Relevant bibliographies by topics / Yeast Biochemistry / Dissertations / Theses

Dissertations / Theses on the topic 'Yeast Biochemistry'

To see the other types of publications on this topic, follow the link: Yeast Biochemistry.
Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Yeast Biochemistry.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Chelebi, Noorhan Ali. "Steryl ester and lipid particle biochemistry in yeast Saccharomyces cerevisiae." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264296.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Guy, Colin Paul. "RadB from archaea : bioinformatics, biochemistry and yeast two-hybrid analyses." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446393.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Goyer, Charles. "Characterization of yeast cap binding proteins." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41144.

Full text
Abstract:
The prominent role played by the cap structure in ribosome binding is mediated by the cap binding protein complex (eIF-4F). The importance of eIF-4F in the regulation of gene expression has been demonstrated in both mammalian and yeast cells. Nevertheless, the function of the high molecular weight subunit of eIF-4F is unknown. Here we describe the isolation and characterization of yeast eIF-4F (24- and 150-kD) as well as a novel CBP of 96-kD. The yeast gene TIF4631 encoding p150 and a closely related gene, TIF4632 were isolated. TIF4631 and TIF4632 are 53% identical, carry out an essential function, display sequences closely resembling the RNA recognition motif (RRM) and are homologous to the high molecular weight subunit of human eIF-4F (p220). The presence of an RRM-like sequence in TIF4631 is consistent with its RNA binding properties and promises to challenge the current views on how cap-dependent and cap-independent ribosome binding operate in eukaryotes.
APA, Harvard, Vancouver, ISO, and other styles
4

Eaglestone, Simon Spencer. "Studies of Sup35p : a yeast prion protein." Thesis, University of Kent, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297347.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Pratt, Kathryn Alice. "Expression of wheat gluten protein in yeast." Thesis, University of Kent, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236722.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Chu, Clement SM. "Towards the structure of yeast prions." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3390039.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hashmi, Salman. "The Cytotoxic Effect of Methylglyoxal on Yeast Cell Growth." Thesis, The George Washington University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10123815.

Full text
Abstract:

The Cytotoxic Effect of Methylglyoxal on Yeast Cell Growth Methylglyoxal (MG) is a highly reactive, cytotoxic dicarbonyl compound, mainly formed as a by-product of glycolysis. It is one of the most potent glycating agents and readily reacts with proteins, lipids and nucleic acids to form advanced glycation end products (AGEs). However, the molecular targets of MG are largely unknown. Glucose is the preferred carbon source of yeast Saccharomyces cerevisiae which it can sense and utilize efficiently over a broad range of concentrations. It prefers to ferment rather than oxidize glucose, even when oxygen is abundant. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of genes encoding glucose transporters (Hxts). Using molecular and cell biology approaches, including Western blotting, qRT-PCR analysis and fluorescence microscopy, I have provided evidence that MG inhibits expression of the Hxts (Hxt1 and Hxt3) by inactivating the low-affinity yeast glucose sensor Rgt2. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensor. However, the glucose sensor with mutations at their putative ubiquitin-acceptor lysine residues is resistant to MG-induced degradation. The results of this study suggest that the low-affinity glucose sensor Rgt2 is inactivated through ubiquitin-mediated endocytosis and degraded in the presence of MG. Under physiological conditions, MG is detoxified by the glyoxalase system into D-lactate, with glyoxalase 1 (Glo1) as the key enzyme in the anti-glycation defense. This study further indicates that the inhibitory effect of MG on the glucose sensor is greatly enhanced in the cells lacking Glo1. Thus, the stability of this glucose sensor seems to be critically regulated by intracellular MG levels. Taken together, these findings suggest that MG attenuates glycolysis by promoting degradation of the cell surface glucose sensor and thus identify MG as a potential glycolytic inhibitor.

APA, Harvard, Vancouver, ISO, and other styles
8

Motshwene, Precious Gugulethu. "Yeast cell wall proteomics: a tale of two proteins." Master's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/4300.

Full text
Abstract:
Bibliography: leaves 53-57.
This thesis investigates cell wall proteins, the presence of which increased in concentration as a result of stress. Two such proteins were found, phosphoglycerate mutase and Hsp 12. Studies on these proteins are reported in chapters 2 (phosphoglycerate mutase) and chapter 3 (Hsp 12).
APA, Harvard, Vancouver, ISO, and other styles
9

White, Malcolm F. "Yeast phosphoglycerate mutase studied by site-directed mutagenesis." Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/24419.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Grob, Ralph. "Variability and optimisation of yeast intracellular enzyme yield." Thesis, University of Surrey, 1991. http://epubs.surrey.ac.uk/843035/.

Full text
Abstract:
The variability of the yield of the intracellular enzyme cytochrome P-450 in Saccharomyces cerevisiae NCYC 754, in closed batch fermentation using a 5-litre computer-controlled stirred-tank fermenter, was investigated using two control strategies: a) Conventional constant set-point control, using previously determined optimal control parameters; b) time-profiled control of three fermenter control parameters, pH, temperature and stirrer speed varied with time according to pre-calculated profiles, computed from a single empirical model using Pontryagin's continuous maximum principle. Cytochrome P-450 was assayed using the reduced carbon monoxide spectrophotometric procedure. The sample treatment and carbon monoxide gassing rate having been optimised before. The accuracy of the fermenter control variables was assessed. The sum of the squared differences (SSD) between the set and actual control values was used. The values of the SSD were related to the enzyme yield. It was found that the enzyme yield was strongly affected by the accuracy of the control, as expected in a near optimal system. It was noted that inaccurate control always gave low enzyme yields, while accurate control gave a range of enzyme yields. It was concluded that yield variability was caused by more than one factor, including the accuracy of control, but that the accuracy of control was overriding. It was found that the accuracy of control of the individual variables depended on the control strategy used. It was concluded that this provides a useful practical method of assessing operational control efficiency, as opposed to analysis of individual control loops, in analysing process efficiency. Analysis of batch to batch variation in components of the complex growth-medium showed that the enzyme yield was affected. Changes in the batch of yeast extract were found to have most effect on the enzyme yield, mycological peptone less so and the glucose and salt virtually none at all. It was concluded that the saving in cost of growth medium, by partially replacing mycological peptone with yeast extract, may be offset by the costs arising from the resulting greater variability in yield. The effect on enzyme yield of the method of sterilising the growth medium indicated that the complex medium contained material which inhibited enzyme production. This material was believed to affect the rheology and the mass-transfer properties of the growth-medium. Analysis of the time interval between the occurrence of the biomass and the enzyme concentration peaks during the fermentation showed that, in this system, the biomass peak always preceded the enzyme peak. In "slower" fermentations the time interval was smaller. This also explained an apparent discrepancy in behaviour between shake-flask and stirred-tank fermentations. In general, the time interval was slightly shorter under time-profile control than with set-point control fermentations. Exhaust gas analysis data showed that the maximum carbon dioxide concentration occurred at the same time as the minimum oxygen concentration. The turning point consistently preceded the enzyme concentration peak by a virtually constant time interval, this time interval was found to be 69 minutes under set-point control and 56 minutes under time-profiled control. This is potentially valuable in enabling the occurrence of the peak enzyme concentration to be predicted accurately, with consequent saving in process time and enzyme yield.
APA, Harvard, Vancouver, ISO, and other styles
11

Chen, Leanna. "Construction of a comprehensive yeast endoplasmic reticulum interactome." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66950.

Full text
Abstract:
Protein-protein interactions in the endoplasmic reticulum (ER) are essential for concerted action of higher molecular complexes. However, the presence of transmembrane domains (TMDs) in many ER proteins and the environmental conditions of the ER prohibit protein-protein interactions from being identified in the ER. To detect interactions between membrane and luminal proteins of the ER, the ER Membrane Yeast Two-Hybrid (MYTH) system uses the ER type 1 membrane protein Ire1p as a reporter of protein interactions in the ER. A hyperactive Ire1p system was developed to determine the C-terminal topologies of ER and ER-related proteins to generate functional N-terminal fusions to Ire1p for the MYTH system. Among 256 proteins, which were hard to analyze on a high-throughput basis by other approaches, 454 interactions were identified. Results showed novel links between previously established biological processes, such as that between the SRP-dependent and independent pathways, and provided roles for ER and ER-related proteins.
Les interactions protéine-protéine dans le réticulum endoplasmique (RE) sont essentielles pour qu'une action concertée des complexes moléculaires de haut poids ait lieu. Cependant, la présence de domaines transmembranaires dans plusieurs protéines et les conditions environnementales du RE ne permettent pas l'identification des interactions protéine-protéine dans cette organite. Afin de détecter les interactions entre les protéines membranaires et luminales du RE, nous avons utilisé la technique du MYTHS (Membrane Yeast Two-Hybrid System) qui emploie la protéine membranaire de type 1, Ire1p, comme rapporteur des interactions des protéines dans le RE. Un système du Ire1p hyperactif a été développé afin de déterminer la topologie de l'extrémité C-terminale des protéines du RE ainsi que celles qui sont y reliées en les fusionnant à l'extrémité N-terminale du Ire1p du MYTHS. Parmi les 256 protéines qui étaient difficiles à analyser par d'autres méthodes à haut débit, 454 interactions sont identifiées. Les résultats démontrent des nouveaux liens entre les fonctions biologiques déjà établies comme celles entre les voies dépendantes et indépendantes de la particule de reconnaissance du signal (SRP) et postulent des rôles aux protéines du RE ainsi qu'à celles qui y sont reliées.
APA, Harvard, Vancouver, ISO, and other styles
12

Eurwilaichitr, Lily. "Structure-function studies of yeast SUP45p (eRF1) protein." Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283974.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Guzman-Juarez, M. "Yeast protein products : Preparation, characterisation and functional properties." Thesis, University of Reading, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376661.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Talreja, Kavita. "Stress induced changes at the yeast plasma membrane." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321558.

Full text
APA, Harvard, Vancouver, ISO, and other styles
15

Garnham, Geoffrey William. "Salt tolerance in the marine yeast Debaryomyces hansenii." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303646.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

McGoldrick, Eamon Michael John. "Control of proliferation in the yeast Saccharomyces cerevisiae." Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370665.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Lau, Andrea. "Synthetic dosage lethal analysis of the yeast NuA4 complex." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28532.

Full text
Abstract:
The NuA4 complex is the only essential lysine acetyltransferase in Saccharomyces cerevisiae and is evolutionarily conserved with the human Tip60 complex, which has been implicated in a wide variety of pathologies. NuA4 plays roles in processes that range from DNA repair to gluconeogenesis. To further investigate the cellular processes impacted by and to identify new targets of NuA4, a genome-wide synthetic dosage lethal screen was performed. This analysis produced an extensive network of genetic interactions, and identified a novel link between NuA4 and septin assembly and cytokinesis. I determined that NuA4 mutants have defects in septin structure, which lead to activation of the morphogenesis checkpoint. Further, I determined that NuA4 is working directly in the septin assembly pathway, potentially by regulating the protein levels of the septin Shs1. My study has revealed a new and important role for NuA4 in regulating the cell cycle and chromosome stability.
APA, Harvard, Vancouver, ISO, and other styles
18

Lawrence, Clare Louise. "Factors affecting the aggregation of yeast prion protein Sup35p." Thesis, University of Kent, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246590.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Rolph, C. E. "Control of lipid desaturation in the yeast Rhodotorula gracilis." Thesis, Bucks New University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384750.

Full text
APA, Harvard, Vancouver, ISO, and other styles
20

Seymour, Ian Jonathan. "Weak acid effects on stress gene activity in yeast." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298866.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Terali, Kerem. "Characterisation of the yeast Nfs1/Isd11 cysteine desulphurase complex." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/572.

Full text
Abstract:
Small inorganic assemblies of alternating ferrous/ferric iron and sulphide ions, so-called iron–sulphur (Fe–S) clusters, are probably nature‟s most ancient prosthetic groups. These multipurpose reactive centres are biosynthesised by dedicated Fe–S cluster assembly proteins which are conserved in the mitochondria of all eukaryotes. One of the early actors in Fe–S cluster biosynthesis is a cysteine desulphurase, Nfs1, which catalyses the release of elemental sulphur from cysteine and plays a key role in its transfer to a molecular scaffold. Recent work has discovered that these reactions require the involvement of a small adaptor protein, Isd11. Isd11 belongs to the LYR family of proteins and helps stabilise Nfs1 upon binding. In this Thesis, heterologous production of soluble yeast Nfs1 on its own as well as in complex with yeast Isd11 in E. coli is presented. In the absence of Nfs1, Isd11 aggregated in the form of inclusion bodies from which the in vitro recovery of soluble protein could not be achieved. Both Nfs1 and the Nfs1/Isd11 complex were shown to be active, reflecting the correct fold of Nfs1. Biophysical approaches were used to provide new insights into the stoichiometry and structure of the Nfs1/Isd11 complex.
APA, Harvard, Vancouver, ISO, and other styles
22

Toyama, Brandon Hiroyuki. "The structural basis of yeast prion strain variants." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3378511.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

Mtwisha, Linda. "Isolation and characterisation of a LEA-like protein from yeast (Saccharomyces cerevisiae)." Master's thesis, University of Cape Town, 1998. http://hdl.handle.net/11427/9685.

Full text
Abstract:
Bibliography: leaves 48-53.
LEA proteins are plant proteins that are characteristically hydrophilic and soluble at elevated temperature. The consistent correlation between desiccation tolerance in orthodox seed tissue and an accumulation of LEA proteins suggests that these proteins play an important role in protecting cells from desiccation induced damage. Yeast (Saccharomyces cerevisiae) has been known to desiccate as part of its normal growth cycle and to remain viable after long periods in the desiccated state. As a result of these properties this project was designed to investigate the presence of LEA-like proteins in yeast. A protein was isolated from baker’s yeast that fulfils the requirements for being a LEA protein. This protein, with a molecular mass of 11 kDa, was found to be the most prevalent heat soluble protein in the yeast extract. Antibodies raised against LEA group I proteins recognised this 11 kDa yeast protein in the total extract but failed to recognise the protein after heat treatment at 80°C for 10 min. Amino acid analysis showed that the ll kDa protein was highly hydrophilic - a characteristic of LEA proteins. The protein was partially sequenced (10 cycles) after CNBr digestion and the sequence obtained was compared with the sequence of known proteins in the Stanford databank. Only one protein, HSP 12, was identified to be 100 % homologous to the obtained sequence without the introduction of gaps. Despite a previous report that HSP 12 is a heat shock protein, HSP 12 was present in a reduced concentration in yeast grown at 37 °C compared with yeast grown at 30 °C. HSP 12 was found to increase in concentration after entry into stationary phase - a time when nutrients are limiting and the yeast is preparing to reduce its water content and sporulate. This might be considered equivalent to plant seed maturation - the stage when LEA proteins are synthesised. Moreover, growth conditions that have been reported to stimulate LEA protein biosynthesis in plants also stimulated HSP 12 synthesis in yeast. Purified HSP 12 was shown to inhibit thermal denaturation of yeast alcohol dehydrogenase (ADH) at elevated temperatures. This is a functional property of the pea seed p11 LEA group I protein. From the above results, it was therefore concluded that HSP 12 should be identified as a LEA-like protein rather than as a heat shock protein.
APA, Harvard, Vancouver, ISO, and other styles
24

Gerien, Kenneth S. "The roles of Mso1 and Sec1 in fission yeast exocytosis during cytokinesis." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595586710049398.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Yarashus, Heather R. "Stripping and Reassembly of the Yeast Vacuolar H+-ATPase Peripheral Protein Subunits." W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539625807.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

Zunder, Eli Richard. "A yeast screen for PI3K inhibitor resistance." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3339211.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Armes, Helen Elizabeth Harcourt. "Implementing super-resolution palm microscopy in fission yeast." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/67027/.

Full text
Abstract:
Fluorescence microscopy is a popular biological technique because it allows the study of cells in great detail. However, the resolution achievable is limited by the diffraction properties of light, meaning that fine detail cannot be resolved. Various super-resolution microscopy methods have been developed to break this resolution limit. This thesis focuses on the single molecule localisation microscopy techniques. My host laboratory focuses on DNA replication and repair pathways using the model organism Schizosaccharomyces pombe (fission yeast). The aim of this thesis is thus to apply the technique of photo-activatable localisation microscopy (PALM) to specific biological questions in order to establish its benefits and limitations. In theory, in PALM every molecule will be imaged once and, as such, could be counted. So far this has been largely limited to membrane proteins. Using a combination of artificially created fluorescent oligomers, endogenous ribonucleotide reductase proteins tagged with mEos and computer simulations I studied the feasibility of counting highly expressed cytoplasmic proteins and assigning them to complexes of known or unknown stoichiometry. I established that density of expression is a significant limiting factor when using PALM to resolve complex stoichiometry. I thus went on to develop a variation of fluorescence correlation spectrometry to study the same protein complexes to see if we could determine their stoichiometry by diffusion speed. I established that the technique could differentiate between quite small changes in size. However the endogenous complex did not respond well to the fluorophore used so I was not able to establish its size. Using the PALM system I also studied a biological molecule, Rrp2, which was expressed at such low levels it was not possible to observe with conventional fluorescence microscopy. I established that we were able to observe this protein at endogenous levels and characterised its behaviour in response to stress.
APA, Harvard, Vancouver, ISO, and other styles
28

Hüsler, Jennifer. "Biosynthesis of Cucurbita maxima trypsin inhibitor I in the methylotropic yeast Pichia pastoris." Master's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/20454.

Full text
Abstract:
Squash inhibitors are the smallest natural serine protease inhibitors. Their compact, rigid nature has enabled detailed examination of their 3D structure by NMR and X-ray crystallography. Being of a convenient size to synthesise chemically, the effects on activity of selective substitutions and deletions within the sequence have also been investigated. Thus, this family of inhibitors is considered useful as a model system for the study of protein-protein interactions. Cucurbita maxima trypsin inhibitor I (CMTI I) may be thought of as representative of the squash inhibitors, for which there is detailed structural and functional information available. It is a 29 amino acid protein, with the tri-disulphide bridging pattern common to all squash inhibitors. There are only a few examples of squash inhibitors being produced by recombinant DNA technology. As this technique offers a relatively cheap way of producing large amounts of these proteins, further investigation is required. Problems have been experienced with the expression of disulphide-rich proteins in E. coli, as the cytosol of this microorganism is not conducive to their folding. Furthermore extraction of these proteins from the peri plasmic space is often required, resulting in a reduction in yield. To overcome these shortcomings, the methylotrophic yeast Pichia pastoris was investigated as an alternative means of expression, although at the inception of this work, no disulphide-rich proteins of this size had been expressed in P. pastoris. It was a challenge to investigate the feasibility of producing squash inhibitors in this expression host and to compare the activity of the recombinant inhibitor to that of native CMTI I.
APA, Harvard, Vancouver, ISO, and other styles
29

Hüsler, Jennifer. "Biosynthesis of Cucurbita maxima trypsin inhibitor I in the methylophic yeast Pichia pastoris." Master's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/19711.

Full text
Abstract:
Squash inhibitors are the smallest natural serine protease inhibitors. Their compact, rigid nature has enabled detailed examination of their 3D structure by NMR and X-ray crystallography. Being of a convenient size to synthesise chemically, the effects on activity of selective substitutions and deletions within the sequence have also been investigated. Thus, this family of inhibitors is considered useful as a model system for the study of protein-protein interactions. Curcrbita maxima trypsin inhibitor I (CMTI I) may be thought of as representative of the squash inhibitors, for which there is detailed structural and functional information available. It is a 29 amino acid protein, with the tri-disulphide bridging pattern common to all squash inhibitors. There are only a few examples of squash inhibitors being produced by recombinant DNA technology. As this technique offers a relatively cheap way of producing large amounts of these proteins, further investigation is required. Problems have been experienced with the expression of disulphide-rich proteins in E. coli, as the cytosol of this microorganism is not conducive to their folding. Furthermore extraction of these proteins from the peri plasmic space is often required, resulting in a reduction in yield. To overcome these shortcomings, the methylotrophic yeast Pichia pastoris was investigated as an alternative means of expression, although at the inception of this work, no disulphide-rich proteins of this size had been expressed in P. pastoris. It was a challenge to investigate the feasibility of producing squash inhibitors in this expression host and to compare the activity of the recombinant inhibitor to that of native CMTI I.
APA, Harvard, Vancouver, ISO, and other styles
30

Tan, Elaine. "Interactions of p24 proteins characterized by yeast two-hybrid, mutagenesis, and overexpression." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40758.

Full text
Abstract:
The evolutionary conserved and abundant p24 proteins cycle through the early secretory pathway, but their cellular functions are still poorly understood. They are not essential in yeast, but in mice, p23 knockout is embryonic lethal. Moreover, p23 is involved in Alzheimer’s disease pathogenesis. The p24 proteins have the ability to form hetero-complexes. Here, the pairwise interactions among p24s, in yeast and human, were determined by yeast two-hybrid. The p24 interactions are specific and occur mostly through their GOLD domain with some contribution from their DOG sequence. Mutagenesis experiments suggested that two p24s interact differently with a common p24 partner. Finally, co-overexpression of p24s in yeast has a harmful effect on a subset of combinations. Some have a growth defect whereas others have a cell size increase phenotype or both. I propose that the p24 proteins might participate in transport of GPI-anchored proteins involved cell wall maintenance or cell cycle pathways.
Les abondantes protéines de la famille p24 sont conservées dans l’évolution et circulent dans la voie sécrétoire précoce, mais leurs fonctions cellulaires sont encore mal définies. Ils sont dispensables chez la levure, mais un knock-out de p23 est létal embryonnaire chez la souris. De plus, p23 est impliqué dans la pathogénèse de la maladie d’Alzheimer. Les protéines p24 peuvent former des hétéro-complexes. Dans cette étude, les interactions des p24s sont déterminées par double hybride. Elles sont spécifiques et se font surtout par leur domaine GOLD avec une contribution de leur séquence DOG. Les expériences de mutagénèse révèlent que deux p24s interagissent différemment avec un p24 commun. La co-surexpression de certains p24s dans la levure cause la mort ou l’élargissement des cellules. Je propose que les protéines p24s participent dans le transport des protéines à ancrage GPI impliquées dans l’entretien de la paroi cellulaire et dans les voies du cycle cellulaire.
APA, Harvard, Vancouver, ISO, and other styles
31

Win, Thein Zaw. "Characterisation of two class V myosins in the fission yeast Schizosaccharomyces pombe." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247086.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Schaschke, C. J. "Growth and mathematical modelling of recombinant yeast in batch and continuous culture." Thesis, University of Strathclyde, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293380.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Wilcox, Andrew. "Cloning of novel insulin-signalling proteins using the yeast two-hybrid system." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272849.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Novo, Molinero Maite. "Biochemistry and physiology of rehydration and adaptation of active dry wine yeast for winemaking." Doctoral thesis, Universitat Rovira i Virgili, 2006. http://hdl.handle.net/10803/8659.

Full text
Abstract:
Alcoholic fermentation is a process mainly characterised by several factors that induce yeast stress response (low pH, high osmotic pressure, low nitrogen content, etc). Thus, stress response is essential to yeast in order to assure its survival, adaptation and growth, in both natural habitats and industrial conditions such as winemaking. One of the main features to optimise and improve alcoholic fermentation is the establishment of metabolic and physiological changes by the yeast just after must inoculation. In this early phase, yeast must quickly change its metabolism to achieve maximum advantage in the new growth medium. Oenological industry uses selected active dry wine yeast (ADWY) to inoculate the musts in order to get a better control over the fermentation process. Those dry yeasts have to be rehydrated before must inoculation. Therefore, yeast rehydration is the first step to ensure healthy cells and a good fermentation performance. The knowledge of the early yeast metabolic responses, from a biochemical and physiological point of view, were the main objectives of this thesis. The studied objectives were:

Analysis of trehalose and glycogen metabolism (reserve carbohydrates) in a commercial wine yeast strain, considering these carbohydrates markers of stress response. Study of their metabolism in winemaking conditions, taking into account the fermentation temperature (low 13ºC and control 25ºC), nitrogen content (low 60 mg/l, control 300 mg/l and high 1200 mg/l) and the ADWY rehydration and pre-adaptation.

Determination of early transcriptional responses of yeast just after must inoculation. It was considered the presence of glucose and fructose, the osmotic shock and the yeast metabolic activation, including the presence of the drug Cycloheximide, which is an inhibitor of protein synthesis.

Characterisation of the standard protocol of ADWY rehydration in an oenological context, which is rehydrate in warm water (37ºC) during 30 minutes.

Low fermentation temperatures affected fermentation kinetics, but not induced any additional stress response. In fact, high levels of trehalose were accumulated at control temperature than at 13ºC. In industrial conditions, after a period of pre-adaptation before inoculation, carbohydrates were completely depleted once yeasts were inoculated into the must. Their synthesis started simultaneously with a change in the phase of growth, from exponential to stationary, coinciding with nitrogen depletion.
We also studied rehydration and characterised the early response to synthetic must but also to relevant conditions that ADWY must cope after inoculation (osmotic shock, presence of carbon sources). Glycogen content did not presented any change. However, trehalose was early mobilised in those media capable to ensure yeast growth.
The effect of nitrogen availability upon trehalose metabolism was also studied. Neither glucose nor nitrogen exhaustion were involved in the regulation of trehalose metabolism. TPS1 (gene which codifies for trehalose-6-phosphate synthase) was induced just before trehalose accumulation, simultaneously with growth arrest. Microarray technique was used to determine whole gene expression after rehydration and in the same conditions previously studied. We can conclude that 30 minutes of rehydration in water is enough for the yeast to fully recover and that longer times in this medium are detrimental. The yeast transcriptional switch is the presence of fermentable sugars, and this is mostly related to ribosome and protein synthesis, glycolysis and ethanol synthesis.
La fermentació alcohòlica és un procés bàsicament caracteritzat per una sèrie de factors que indueixen estrès al llevat, el microorganisme responsable de la seva consecució. La resposta a estrès per part del llevat és essencial per a la seva supervivència, adaptació i creixement, tant en medis naturals com en processos industrials (enologia). Una de les principals característiques per a l'optimització de la fermentació alcohòlica és l'establiment de canvis metabòlics i fisiològics del llevat just després de la inoculació en el most. És en aquesta fase inicial quan el llevat ha de canviar ràpidament el seu metabolisme per tal d'adquirir el màxim d'avantatge en el nou medi de creixement. La indústria enològica disposa de llevats secs actius (LSA) seleccionats que s'inoculen al most per tal d'assolir un millor control sobre el procés fermentatiu. Aquests llevats secs requereixen d'una rehidratació prèvia a la inoculació en el most. La rehidratació és el primer pas per tal d'assegurar el bon estat cel.lular i una bona fermentació alcohòlica. El coneixement de les respostes metabòliques inicials del llevat des d'un punt de vista bioquímic i fisiològic foren els objectius fonamentals d'aquest treball. Els objectius van ésser:

- Anàlisi del metabolisme de trehalosa i glicogen (carbohidrats de reserva) en una soca de llevat comercial, com a indicadors de resposta a estrès. Estudi del metabolisme en condicions víniques, considerant com a variables la temperatura de fermentació (baixa, 13ºC i control, 25ºC), contingut en nitrogen (baix 60 mg/l, control 300 mg i elevat 1200 mg/l) i la rehidratació i preadaptació del LSA.
- Determinació de les respostes transcripcionals inicials del llevat immediatament després de la seva inoculació en el most. Es va considerar la presència de glucosa i fructosa, el shock osmòtic i l'activació metabòlica del llevat, incloent la presència de cicloheximida, un inhibidor de la síntesi proteica.
- Caracterització del protocol estàndard de rehidratació del llevat dins el context enològic, que és la utilització d'aigua a 37-40ºC durant 30 minuts.

Les baixes temperatures de fermentació van incidir sobre la cinètica fermentativa, però no sobre una resposta a estrès. De fet, es va trobar major acumulació de trehalosa a temperatura control que a 13ºC. En condicions industrials, després d'un període d'adaptació previ a la inoculació (peu de cuba), els nivells de carbohidrats van ser nuls. La seva síntesi es va produir al canvi de fase exponencial a estacionària, coincidint amb l'esgotament de nitrogen. Es va estudiar la rehidratació i permanença en diferents medis (aigua, glucosa/fructosa, most sintètic i sorbitol). La concentració intracel.lular en glicogen no presentà cap modificació. Però la trehalosa es va metabolitzar en les fases inicials, en aquells medis favorables per al creixement del llevat.

Es va estudiar l'efecte de la disponibilitat de nitrogen sobre el metabolisme de la trehalosa. Independentment del contingut nitrogenat, el seu metabolisme no es va veure modificat. TPS1 (gen que codifica trehalosa-6-fosfat sintasa) es va induir just abans de la acumulació de trehalosa, coincidint amb l'aturada del creixement cel.lular. Mitjançant la tècnica dels "microarrays" es va determinar l'expressió gènica global del llevat després de rehidratar i romandre en els medis anteriors. Podem concloure que el temps de rehidratació utilitzat en enologia assegura la total recuperació de LSA. Temps més llargs afectaren negativament la fisiologia del llevat, reduint significativament la seva vitalitat. Les modificacions transcripcionals al most foren degudes bàsicament a la presència de glucosa i fonts nitrogenades, induint la síntesi proteica, glucòlisi i producció d'etanol.
APA, Harvard, Vancouver, ISO, and other styles
35

Mocke, Leanie. "Kinetic modelling of wine fermentations : why does yeast prefer glucose to fructose." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80316.

Full text
Abstract:
Thesis (MSc)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: In the present-day competitive global market, wine industries are constantly aiming to improve the wine-making process,including the role of yeast. The most commonly used wine yeast is Saccharomyces cerevisiae, which is able to produce high quality wines, but problem fermentations do sometimes arise. The occurrence of stuck and sluggish fermentations pose a serious problem leading to loss of productivity and quality. Although the precise mechanism leading to stuck fermentations is unknown, they are often correlated with high fructose to glucose ratios in the wine-must. S. cerevisiae is a glucophylic yeast, indicating its preference for consuming glucose over fructose. Both these hexose sugars are present in unfermented wine must, mostly in equal concentrations. As fermentation progresses, glucose is consumed at a faster rate than fructose, leading to an increase in the fructose to glucose ratio. Yeast are left with the undesirable fructose at the later stages of fermentation, when the environmental stresses on the yeast can lead to stuck or sluggish fermentation. This residual fructose can lead to undesirable sweetness, as fructose is about twice as sweet as glucose. Even with the extensive research into yeast metabolism, there is as yet no definitive explanation as to why yeasts ferment glucose faster than fructose. This study aimed to investigate the mechanism responsible for the faster consumption of glucose over fructose of a commercially used wine yeast strain S. cerevisiae VIN 13. The first two steps of sugar metabolism, uptake and phosphorylation, were investigated as the possible sites of discrepancy in fermentation rates. Enzyme rates and affinities for both glucose and fructose as substrates for the relevant enzymes were experimentally determined. These kinetic parameter values were used to improve an existing model of yeast glycolytic pathway to model wine fermentations. The feasibility of constructing and validating a kinetic model of wine fermentations were investigated, by comparing model predicted fluxes with experimentally determined fluxes. Another aspect of this study was an investigation into the effect of hexose sugar type on fermentation profiles. Wine fermentations were done with only one hexose sugar as carbon source to determine if it has an effect on the flux through metabolism. This work succeeded in the construction of a kinetic model that distinguished between glucose and fructose as carbon source. The glucose was consumed faster than fructose, with control lying in the hexose transport step. It was also established that fermentation prfiles of fermentations with only one sugar was the same for both one sugar type fermentations. Fermentation with either glucose or fructose as the sole carbohydrate source had the same specfic production and consumption rates as normal fermentations with both sugars. Construction of detailed kinetic models can aid in the metabolic and cellular engineering of novel yeast strains. By identifying the importance of hexose transport, and thus the glucophilic character of the yeast, in flux control, yeast transporters can be targeted for strain improvement. This may in turn lead to more effective fermentation practices for controlling problem fermentations, or to the development of novel strains that utilizes fructose in the same manner as glucose, and in so doing lower the risk of stuck or sluggish wine fermentation.
AFRIKAANSE OPSOMMING: In die hedendaagse kompeterende wynmark is wynmakers aanhoudend besig om die wynmaak proses te verbeter en dit sluit die verbetering van wyngis in. Die mees algemeenste gebruikte wyngis is Saccharomyces cerevisiae, omdat dit wyn van gehalte produseer, maar probleem fermentasies kom wel voor. Die verskynsel van vasval of stadige fermentasies kan lei tot die verlies van produksie en kwaliteit. Die oorsaak van probleem fermentasies is gewoontlik veelvoudig, maar die verhouding van glukose tot fruktose in die wyn-mos kan ongunstig raak om fermentasies te onderhou. S. cerevisiae is 'n glukofiliese gis, wat sy voorkeur om glukose bo fruktose te gebruik beskryf. Albei hierdie heksose suikers is teenwoordig in ongefermenteerde wyn-mos, meestal in gelyke hoeveelhede. Soos fermentasies vorder word glukose vinniger verbruik as fruktose wat lei tot 'n toename in die fruktose tot glukose verhouding. Die gis moet dus die fruktose in die later stadium van fermentasie gebruik wanneer die omgewings druk op die gis kan lei tot probleem fermentasies. Die oorblywende fruktose kan lei tot ongewenste soetheid aangesien fruktose twee keer soeter is as glukose. Selfs met die ekstensiewe navorsing met betrekking tot gis metabolisme is daar nog nie 'n verduideliking hoekom gis glukose vinniger as fruktose gebruik nie. Hierdie studie het beoog om die meganisme wat lei tot die vinniger verbruik van glukose oor fruktose te ondersoek vir 'n kommersieël gebruikte gis S. cerevisiae VIN 13. Die eerste twee stappe van suiker metabolisme, suiker opname en fosforilasie, was ondersoek as die moontlike punt van die verskil in fermentasie tempo. Ensiem snelhede en affiniteite vir beide glukose en fruktose as substrate vir die ensieme van belang was eksperimenteel bepaal. Hierdie waardes is gebruik om 'n bestaande model van gis glikolise aan te pas vir wyn fermentasies. Die uitvoerbaarheid van saamstel en valideer van 'n kinetiese model van wyn fermentasies was ondersoek, deur model voorspelde fluksie waardes met eksperimentele fluksie waardes te vergelyk. 'n Ander aspek van die studie was die ondersoek van die effek van heksose suiker tipe op fermentasie profiel. Wyn fermentasies is gedoen met slegs een heksose suiker as koolstof bron om te bepaal of dit 'n invloed het op die fluksie deur metabolisme. Hierdie werk het daarin geslaag om 'n kinetiese model saamtestel wat onderskei tussen glukose en fruktose as koolstof bron. Die glukose is vinniger verbruik as fruktose, met beheer gesetel in die heksose opname stap. Dit was ook vasgestel dat fermentasie profiele van fermentasies met slegs een suiker nie verskil het vir fermentasies met slegs fruktose of glukose. Fermentasies met slegs een suiker het dieselfde spesifieke produksie en konsumpsie tempo gehad as die normale fermentasie met albei suikers. Die konstruksie van 'n gedetailleerde kinetiese model kan gebruik word in die metaboliese en sellulêre ontwikkeling van nuwe gisstamme. Deur die ontdekking van die belangrikheid van heksose opname in fluksie beheer, wat lei tot die glukofiliese karakter van gis, kan gis opname geteiken word vir gis ontwikkeling. Dit mag om die beurt lei tot meer effektiewe fermentasie praktyk in die beheer van probleem fermentasies, of die ontwikkeling van nuwe stamme wat fruktose in dieselfde manier as glukose benut, en sodoende die risiko van vasval of stadige wyn fermentasies verlaag.
National Research Foundation
Post-graduate Merit Bursary
APA, Harvard, Vancouver, ISO, and other styles
36

Flanagan, Timothy. "Studies on yeast D-xylulokinase : purification and properties from Pichia stipitis NCYC 1541." Thesis, London South Bank University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334392.

Full text
APA, Harvard, Vancouver, ISO, and other styles
37

Cronin, Nora Bernadette. "X-ray structural analysis of six inhibitors bound to yeast aspartic proteinase A." Thesis, Birkbeck (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300532.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Hartley, Alan David. "Factors affecting translation initiation in the yeast Saccharomyces cerevisiae : an in vitro study." Thesis, University of Kent, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332518.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Wilkinson, Marc George. "Functional analysis of the STY1 stress-activated map kinase pathway of fission yeast." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286786.

Full text
APA, Harvard, Vancouver, ISO, and other styles
40

Farzadfar, Rahin. "Identification of Artemis and PARP-1 interacting factors: A yeast two hybrid screening approach." Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28481.

Full text
Abstract:
The genomic integrity of the cell is under the constant threat of DNA damage from endogenous and exogenous sources. In response to DNA damage mammalian cells elicit a highly complex, yet coordinated series of cellular responses, which are triggered by the detection of DNA lesions and ultimately lead to cell survival (DNA repair) or apoptosis. Artemis and PARP-1 are two proteins with significant implications in the various branches within the DNA damage response network. A series of yeast two hybrid screening (Y2H) experiments were conducted using both classical and interacting mating Y2H systems to find Artemis and PARP-1 interacting factors. The ATRX protein was identified as a putative interactor of Artemis, Caspase-7 and an "unkown" protein were identified as putative interactors of PARP-1 binding factors. In addition a rare case of false positives were identified and characterized. Furthermore, the strengths and limits of each Y2H system, as well as troubleshooting techniques developed to increase the efficiency of each system were thoroughly examined.
APA, Harvard, Vancouver, ISO, and other styles
41

Murcott, Toby Howard Latutin. "A study of wild type and two site specific mutants of yeast pyruvate kinase." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303853.

Full text
APA, Harvard, Vancouver, ISO, and other styles
42

Lebo, Kevin. "The Driving Forces of Peptide Aggregation: A Study of the Yeast Sup35 Prion Fragment GNNQQNY." Thesis, Boston College, 2008. http://hdl.handle.net/2345/549.

Full text
Abstract:
Thesis advisor: Jianmin Gao
Protein aggregation can be highly detrimental to organisms, and has been associated with diseases including Alzheimer's, Huntington's, type II diabetes, and transmissible spongiform encephalopathies such as Mad Cow disease. There is no single amino acid sequence responsible for aggregation into amyloid-like structures, but rather a large range of amyloidogenic peptides have been discovered. A fragment of the yeast Sup35 prion, GNNQQNY, has been found to aggregate using a "dry, steric zipper" structure. This study looks at mutants of GNNQQNY in order to elucidate the exact contributions of various amino acids to the aggregation process
Thesis (BS) — Boston College, 2008
Submitted to: Boston College. College of Arts and Sciences
Discipline: Chemistry
Discipline: College Honors Program
APA, Harvard, Vancouver, ISO, and other styles
43

Sinclair, Kirsty Ellen. "Effects of the yeast ubiquitination system on proteins accumulated at the entry to stationary phase." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299751.

Full text
APA, Harvard, Vancouver, ISO, and other styles
44

Gilbert, S. C. "Studies on lipid accumulaltion and genetics of Rhodosporidium toruloides." Thesis, University of Hull, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381881.

Full text
APA, Harvard, Vancouver, ISO, and other styles
45

Friday, Dillon R. "Processing of Potato Spindle Tuber Viroids (PSTVd) RNAs in Yeast, a Nonconventional Host." Thesis, University of the Sciences in Philadelphia, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10692985.

Full text
Abstract:

The discovery of viroids in 1971 opened the door to a whole new field of RNA biochemistry. Viroids subsequently became the first of many facets of RNA biochemistry: the first single stranded covalently closed RNA discovered in nature, the first subviral pathogen discovered, and the first pathogen of a eukaryotic system to have its genome sequenced. Viroids are the smallest known agents of infectious disease and they represent the borders of life. They replicate autonomously within their host and since they do not code for their own proteins, they act as scavengers of the host transcriptional machinery. By doing so, viroids find ways of trafficking, localizing, and replicating within their host based on the sequence and structure of the RNA alone. Once in their hosts, viroids are incredibly resilient and can cause economic damage on several commercial crops. Apart from controlling viroids for economic reasons, the more enticing feature of viroid study is the use of viroids as model systems to study essential underlying questions about the evolution of RNA pathogens, and to use viroids as models to study non-coding RNAs. The field of non-coding RNA research has surged within the past decade and viroids are becoming important vehicles to bring insight into this field of study. The study of viroids has been extensive through the years, but several questions remain: What structural conformations do viroids employ to recruit host enzymes, and what are the enzymes that cleave and ligate viroids into mature progeny. To answer some of these questions, we have looked at processing of the potato spindle tuber viroid (PSTVd) RNA in the budding yeast Saccharomyces cerevisiae. We found that one specific construct will process into a mature viroid circle in yeast and we also found that processing in this system is distinct from other plant and non-plant based host systems. This processing is a delicate interplay of ligation and degradation by host machinery. Yeast is a great system to study viroid processing as yeast allows for use of the entire toolbox of temperature-sensitive and knockout protein mutants. By employing yeast, focus can be driven towards the mechanisms of host protein recruitment, viroid processing requirements, and degradation mechanisms from the host. We have ascertained insight into PSTVd processing using yeast. We have found methods to transform and process PSTVd, investigated enzymes that effect processing, and started to establish an in vitro yeast system. Through these studies, we have also developed a method to enrich viroid RNAs from total RNA extractives. This has been vital to assays specific around viroid transcription and cleavage. Overall, this research is further testament that viroids are minimalist scavengers of a very diverse array of cellular transcriptional machinery. They can process in higher eukaryotes (plants) and simple eukaryotes (yeast). They are shown to affect each host in distinct manners using fundamental RNA biology that all organisms share.

APA, Harvard, Vancouver, ISO, and other styles
46

Jones, Brittnee. "Structural and enzymatic characterization of the yeast mRNA decapping enzyme, Dcp2." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2010. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3390050.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Excell, Celeste. "Pop2: A Potential Regulator of Hmt1-Catalyzed Arginine Methylation in Yeast." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/2104.

Full text
Abstract:
Protein arginine methylation is an important post-translational modification that is vital in regulating various cellular processes such as gene transcription, cell signaling, and RNA processing. Protein arginine methyltransferases (PRMTs) are responsible for performing this important modification. PRMT1 (protein arginine methyltransferase 1) and Hmt1 (hnRNP methyltransferase 1) are the predominant PRMTs in humans and yeast, respectively. Despite growing momentum in this field, relatively little is understood about PRMT regulation. Further work discovering how PRMTs are regulated will greatly advance our understanding of diseases where PRMTs have been implicated, such as heart disease, viral pathogenesis, and cancer. It has been discovered that a human protein called hCaf1 (human Ccr4-associated factor 1) is a regulator of PRMT1 with respect to certain substrates, and also colocalizes with PRMT1. We present data that suggest the yeast homolog of hCaf1, Pop2, may also perform a similar function on Hmt1. We provide data on the expression and purification of a truncation of Pop2 from S. cerevisiae, including the temperature sensitivity of one construct of Pop2 and its susceptibility to precipitation. We also demonstrated concentration-dependent inhibition of Hmt1-catalyzed methylation of histone H4 by Pop2 in vitro. Yeast cell lysates also showed altered patterns of methylation in the presence and absence of Pop2 in vivo. In an effort to understand the mechanism employed by Pop2 to accomplish this regulatory function, pull-downs were performed suggesting that Pop2 directly interacts with histone H4, a substrate of Hmt1. Mutagenic studies with Pop2 suggested a region that may be responsible for this interaction. Given these data, we hypothesized that Pop2 is able to inhibit the methylation of histone H4 via a substrate-sequestering mechanism. Further experimentation will determine the precise interaction surfaces of Pop2 and substrate, and continue to define the details of methylation inhibition by Pop2, including the scope of its influence in the cell.
APA, Harvard, Vancouver, ISO, and other styles
48

Huang, Ri-Bo. "Selective separation of yeast proteins by differential product release, enzymitic lysis and aqueous two-phase systems." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280269.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Raby, Roger Lee Jr. "Cloning and Overexpression of Yeast Cystathionine γ-Lyase." Youngstown State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1355527551.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Lipari, Francesco. "Structure and mechanism of action of the yeast class 1 a1,2-mannosidase involved in N-glycan biosynthesis." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35469.

Full text
Abstract:
The Saccharomyces cerevisiae alpha1,2-mannosidase that removes one specific mannose residue from Man9GlcNAc 2 during the biosynthesis of N-glycans is a member of the Class 1 alpha1,2-mannosidase family conserved through eukaryotic evolution. These alpha1,2-mannosidases are type II membrane proteins with an N-terminal transmembrane domain and a large C-terminal catalytic domain. High levels of recombinant yeast alpha1,2-mannosidase catalytic domain were produced using Saccharomyces cerevisiae (0.6 mg/l) and Pichia pastoris (30 mg/l) expression systems, permitting further characterization of the structural and mechanistic properties of the enzyme. Peptide analysis was applied to localize the two disulfide bonds (Cys340-Cys385 and Cys468-Cys 471) and free thiol group (Cys485). Atomic absorption analysis and equilibrium dialysis with 45Ca2+ were used to show that the enzyme binds one Ca2+ ion with high affinity. It was also demonstrated by proton nuclear magnetic resonance spectroscopy that the alpha1,2-mannosidase hydrolyzes the substrate with inversion of the anomeric configuration. Site-directed mutagenesis studies were used to determine the importance of the cysteine residues, the invariant acidic residues, and the putative EF hand Ca2+-binding motif. It was shown that the disulfide bond formed by the invariant Cys340 and Cys 385 residues is essential for the structural integrity of the alpha1,2-mannosidase, while the second disulfide bond and free thiol are not necessary for enzyme activity. It was also demonstrated that the EF hand motif is not the site for Ca2+ binding, whereas Asp275, Glu 279, and Glu438 are important for Ca2+ binding, and Asp86, Glu132, Glu503, and Glu526 are likely active site residues. The yeast alpha1,2-mannosidase is the only Class 1 alpha1,2-mannosidase for which both structural and mechanistic properties have been characterized, and it can serve as a model for the other enzymes of the family.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Yeast Biochemistry' for other source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography