Статті в журналах: "Isoelectric focussing"

1

Houston, B., and C. Goddard. "Molecular forms of growth hormone in the chicken pituitary gland." Journal of Endocrinology 116, no. 1 (January 1988): 35—NP. http://dx.doi.org/10.1677/joe.0.1160035.

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ABSTRACT Different forms of GH present in freshly prepared homogenates of chicken pituitary were analysed by high-performance gel permeation chromatography and by immunoblotting following sodium dodecylsulphate polyacrylamide gel electrophoresis, non-denaturing polyacrylamide gel electrophoresis and isoelectric focussing. Chicken GH was found to occur mainly in a monomeric form with a relative molecular mass of 23 500 together with small amounts of interchain disulphide-linked oligomers. No evidence was obtained for proteolytically modified forms of GH nor for a form analogous to the 20K variant of human GH. Isoelectric focussing resolved ten distinct charge variants of chicken GH with isoelectric points between 8·45 and 6·0. The predominant charge variant (pI = 7·85) was present in pituitaries of birds of both sexes at all ages examined (3–114 days) whereas the more acidic forms were not apparent until after day 13. These findings indicate that the chicken pituitary contains different forms of GH, some of which may be developmentally regulated. J. Endocr. (1988) 116, 35–41

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2

Minshull, Thomas C., Amanda Wood, David Roberts, Christine Hallam, Joshua Lewis, Adetola Orekoya, and David Gervais. "Determination of extent of PEGylation using denaturing capillary isoelectric focussing." Analytical Biochemistry 611 (December 2020): 113953. http://dx.doi.org/10.1016/j.ab.2020.113953.

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3

Ataman, Can, Ufuk Çelik, and Hartmut Rehbein. "Identification of some Aegean fish species by native isoelectric focussing." European Food Research and Technology 222, no. 1-2 (October 13, 2005): 99–104. http://dx.doi.org/10.1007/s00217-005-0149-0.

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4

Miao, J. K., X. Q. Yu, and M. Z. Huang. "Study of the Isoelectric Point (IEP) and Isoelectric Point Distribution (IEPD) of Photographic Gelatinwith Isoelectric Focussing on Flat Bed Polyacrylamide Gel." Journal of Photographic Science 40, no. 5-6 (September 1992): 165–67. http://dx.doi.org/10.1080/00223638.1992.11737197.

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5

Pioselli, Barbara, Caroline Munro, Andrea Raab, Christian L. Deitrich, Kriangsak Songsrirote, Jörg Feldmann, and Jane Thomas-Oates. "Denaturing and non-denaturing microsolution isoelectric focussing to mine the metalloproteome." Metallomics 1, no. 6 (2009): 501. http://dx.doi.org/10.1039/b903607e.

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6

Houston, B., I. E. O'Neill, M. A. Mitchell, and C. Goddard. "Purification and biological activity of a single charge isomer of pituitary-derived chicken growth hormone." Journal of Endocrinology 125, no. 2 (May 1990): 207–15. http://dx.doi.org/10.1677/joe.0.1250207.

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ABSTRACT The chicken pituitary gland contains a number of naturally occurring, developmentally regulated forms of GH which have identical molecular weights but differ in their isoelectric points. In order to characterize their biological properties, each must be separated from non-GH proteins and other forms of GH. Chicken GH (cGH) was separated from other pituitary proteins by immunoaffinity chromatography using an anti-GH monoclonal antibody covalently linked to Sepharose 4B. The cGH eluted from this column as a single peak and migrated as a single band during sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), but showed multiple bands on isoelectric focussing. This material was chromatographed on a high-performance cation exchange column, and separation of charge isomers was monitored by a combination of isoelectric focussing and immunoblotting. Chicken GH eluted from this column in two distinct peaks. The minor peak (cGH P1) contained an isomer with an isoelectric point of 6·86 and the major peak (cGH P2) an isomer with an isoelectric point of 7·52. Each isomer migrated as a single band during isoelectric focussing and SDS-PAGE (Mr = 23 500), and as a single peak during high-performance gel permeation chromatography and reverse-phase high-performance liquid chromatography. Analysis of cGH P2 through 30 cycles in a gas-phase microsequencer gave an amino acid sequence identical to that predicted by translation of the GH complementary DNA nucleotide sequence. This single charge isomer increased the rate of lipolysis in chicken adipose tissue explants by about fourfold and was able to displace 125I-labelled cGH from binding sites in liver membranes with a dissociation constant of about 4 nmol/l. The output of insulin-like growth factor-I by hepatocytes in culture was increased from a basal rate of 50·4±11·6 (mean ± s.e.m.) to 787·9 ± 98·6 pg/6 × 106 cells per 48 h by two separate pulses of 1 μg cGH P2/ml. An i.v. injection of cGH P2 (15 μg/kg body weight) decreased the thyroxine:tri-iodothyronine ratio in serum of adult hens from 15·71 to 4·44, indicating an increase in 5′-monodeiodinase activity. These results demonstrate that the single most abundant charge isomer of chicken pituitary GH is likely to contain all the biological activity ascribed to the hormone. Journal of Endocrinology (1990) 125, 207–215

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7

Getliffe, K. A., L. C. Ward, and R. W. Shepherd. "Identification of cystic fibrosis homozygotes and heterozygotes by isoelectric focussing of serum proteins." Journal of Inherited Metabolic Disease 9, no. 4 (December 1986): 348–56. http://dx.doi.org/10.1007/bf01800484.

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8

Bodinet, C., N. Beuscher, and L. Kopanski. "Purification of Immunologically Active Glycoproteins fromBaptisia tinctoriaRoots by Affinity Chromatography and Isoelectric Focussing." Planta Medica 55, no. 07 (December 1989): 659. http://dx.doi.org/10.1055/s-2006-962249.

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9

Kang, Sungzong, and Julian Niemetz. "Purification of Human Brain Tissue Factor." Thrombosis and Haemostasis 59, no. 03 (1988): 400–403. http://dx.doi.org/10.1055/s-0038-1647504.

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SummaryTissue factor (thromboplastin or Factor III), a glycoprotein cofactor, is required for Factor VII to express its catalytic activity, thereby initiating the extrinsic as well as intrinsic pathway of blood coagulation. Human brain tissue factor was purified 2,500-fold to 98% homogeneity from 2% Tiiton X-100 extraction of acetone dried brain powder with an overall yield of 36%. The method was based upon affinity chromatography utilizing the high affinity binding of tissue factor to Factor VII noncovalently complexed to immobilized anti-Factor VII-agarose beads. The apparent molecular weight of the purified tissue factor is 45,000 as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its isoelectric point is 4.8–5.1 by column chromatofocussing and flat bed agarose isoelectric focussing.

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10

Anderson, Carrie L., Yang Wang, and Richard R. Rustandi. "Applications of imaged capillary isoelectric focussing technique in development of biopharmaceutical glycoprotein-based products." ELECTROPHORESIS 33, no. 11 (June 2012): 1538–44. http://dx.doi.org/10.1002/elps.201100611.

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11

William, M. D. H. M., and Abdul Mujeeb-Kazi. "Rapid detection of 1B, 1BL/1RS heterozygotes in the development of homozygous 1BL/1RS translocation stocks of Triticum turgidum (2n = 4x = 28)." Genome 36, no. 6 (December 1, 1993): 1088–91. http://dx.doi.org/10.1139/g93-144.

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A biochemical marker was utilized to facilitate detection of chromosome 1B, 1BL/1RS translocation heterozygote plants in segregating backcross progenies during the development of 1BL/1RS homozygous lines in several Triticum turgidum L. cultivars (2n = 4x = 28; AABB). Isoelectric focussing of glucose phosphate isomerase (GPI) on either pH 3.5–9.5 or 5.5–8.5 polyacrylamide gels facilitated the detection of 1B, 1BL/1RS translocation heterozygotes from the homozygous 1B or 1BL/1RS derivatives during each backcross of the heterozygote to the respective recurrent parent. The biochemical diagnostic procedure complements the more time consuming and cumbersome chromosome banding technique. This GPI diagnostic in durum 1BL/1RS development is also swifter than a similar stocks development in T. aestivum where both GPI and acid PAGE are essential.Key words: Triticum turgidum, glucose phosphate isomerase, 1BL/1RS translocation, isoelectric focusing.

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12

Marvin-Guy, Laure F., Tatiana Zinger, Sandrine Wagnière, Véronique Parisod, Michael Affolter, and Martin Kussmann. "Differential Human Plasma Proteomics Based on AniBal Quantification and Peptide-level Off-Gel Isoelectric Focussing." Proteomics Insights 3 (January 2010): PRI.S4851. http://dx.doi.org/10.4137/pri.s4851.

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Despite its enormous complexity, human plasma is still one of the most frequently used body fluids for identification and quantification of health and disease biomarkers. We have developed a new workflow for qualitative and quantitative analysis of human plasma proteins. The first step was to remove the seven most abundant plasma proteins (MARS). Moreover, in order to reduce the complexity of the sample and to increase protein and proteome coverage, Off-Gel fractionation was performed at peptide level. Our own stable isotope-based quantitative proteomics approach termed AniBAL was chosen for relative quantification of proteins between conditions. The method was developed with commercial human plasma and resulted in the identification of 85 proteins, of which 68 revealed quantitative information (Mascot database search combined with Peptide-/ProteinProphet validation). The combined methods consisting of MARS, AniBAL, Off-Gel and nano-LC-MS/MS on a Bruker HCT ion trap represent a new and efficient platform to quantify human plasma proteome differences between conditions. The method was also found technically compatible to a pair of human plasma pilot samples from the European FP6 project “DiOGenes”. Many of the identifiable/quantifiable proteins are relevant to obesity, diabetes and inflammation, which form the context of investigation within “DiOGenes”.

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13

van Ginkel, L. A., та J. G. Loeber. "Heterogeneity of human luteinizing hormone. Effect of neuraminidase treatment on biologically active hormone and α- and β-subunits". Acta Endocrinologica 114, № 4 (квітень 1987): 577–83. http://dx.doi.org/10.1530/acta.0.1140577.

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Abstract. By preparative isoelectric focussing of a highly purified LH preparation in a sucrose density gradient, four biologically active LH components were isolated. The effect of neuraminidase treatment of each component on the charge heterogeneity was studied by isoelectric focussing followed by in vitro biological and immunochemical techniques. The number of biologically active components with pI-values > 7 containing varying amounts of sialic acid is at least six. The pI-value of the most basic (= asialo) LH component was 9.26. The two most basic components were not present in our preparation (NM 14) before neuraminidase treatment. It is concluded that the difference between the pI-values of LH components is caused by a difference in sialic acid content. When an intact LH component was incubated with neuraminidase there was detectable dissociation owing to the elevated temperature (37°C) and necessary acidic conditions of the incubation. Under these conditions we found the same subunits as we have described before. The most basic α-subunit had a pI-value of 9.29, whereas two β-subunits with pI > 9 were observed at pI 9.26 and pI 9.9. On the other hand, when an LH component was forced to dissociate by incubation at 56°C prior to neuraminidase digestion, two additional α-subunits were found. From this it is concluded that in the intact LH molecule, some sialic acid residues are poorer substrates for neuraminidase action than in the free subunits.

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14

Ceccanti, Brunello, Serena Doni, Cristina Macci, Giovanni Cercignani, and Grazia Masciandaro. "Characterization of stable humic–enzyme complexes of different soil ecosystems through analytical isoelectric focussing technique (IEF)." Soil Biology and Biochemistry 40, no. 9 (September 2008): 2174–77. http://dx.doi.org/10.1016/j.soilbio.2008.02.004.

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15

McDowell, I. F. W., G. B. Wisdom, E. R. Trimble, and D. P. Nicholls. "A simplified method for determination of apolipoprotein E phenotype by isoelectric focussing in agarose and immunoblotting." Atherosclerosis 74, no. 3 (December 1988): 253–54. http://dx.doi.org/10.1016/0021-9150(88)90253-5.

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16

Badour, S. S., and W. K. Kim. "Detection of specific polypeptides in Chlamydomonas segnis adapted to atmospheric concentrations of CO2, using a zwitterionic detergent." Canadian Journal of Botany 66, no. 9 (September 1, 1988): 1750–54. http://dx.doi.org/10.1139/b88-240.

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Polypeptides from 5% CO2 adapted and air-adapted cells of Chlamydomonas segnis, extracted in the presence of the zwitterionic (ampholytic) detergent CHAPS, then lyophilized and washed with a chloroform – methanol mixture, were compared with those extracted in the presence of sodium dodecyl sulphate and Nonidet-P40 and precipitated by cold acetone, using two-dimensional electrophoresis. The electrophoretograms of these detergent-soluble polypeptides indicate that the use of CHAPS instead of sodium dodecyl sulphate – Nonidet-P40 considerably increases the mobility of proteins in the isoelectric focussing gels, improves resolution, and facilitates the detection of polypeptides with low molecular masses on the gradient gels. Comparison of polypeptides extracted with CHAPS from air-adapted and 5% CO2 adapted cells revealed the presence of 20 polypeptides unique to the former type of cells. Fourteen of these polypeptides had molecular masses of approximately 20 kDa and isoelectric-point (pI) values ranging from 7.4 to 6.4. They represented the major proteins characteristic of cells capable of active photosynthesis and growth under atmospheric concentrations of CO2.

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17

Greenstein, B. D., and I. M. Adcock. "Oestrogen receptors and effects of oestradiol administration on mRNA synthesis in the limbic system of the neonatal female rat." Journal of Endocrinology 120, no. 1 (January 1989): 83–88. http://dx.doi.org/10.1677/joe.0.1200083.

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ABSTRACT There is sexual dimorphism of specific species of mRNA in the neonatal rat brain and this sexual dimorphism may be imprinted by steroids of testicular origin during the perinatal period. According to current theories, only aromatizable androgens may cause sexual differentiation of sexual behaviour and function in the adult. The effects of oestradiol benzoate on mRNA synthesis in the neonatal female limbic system were therefore studied. In addition, cytosolic and nuclear oestrogen receptors were measured after administration of testosterone propionate, oestradiol benzoate or dihydrotestosterone (DHT). An attempt was made to distinguish between the brain oestrogen receptor and the plasma oestrogen-binding protein, alphafoetoprotein (AFP) by isoelectric focussing. After injection of 50 μg oestradiol benzoate s.c. to neonatal female rats, the expression of mRNA coding for sexually dimorphic proteins appeared to be changed to a male-type pattern. The overall density of labelling was noticeably greater and specific changes in labelled proteins were observed. These effects were observed within 3 h of injection. Both testosterone and oestradiol caused a marked depletion of cytosolic oestrogen receptors in the limbic system whereas DHT was ineffective in this respect. Nuclear receptors were present in equal abundance in male- and female-derived nuclei and only oestradiol was able to cause a significant (P < 0·025) increase in nuclear oestrogen receptors. The receptor and AFP could be distinguished by isoelectric focussing, since the pI of the receptor was 7·05, while that of AFP was 4·5. These results are consistent with the possibility that oestradiol alters transcription in the neonatal rat brain and may do this through the oestrogen receptor. Nevertheless, it is also possible that oestradiol could alter post-transcriptional events such as the stability of mRNA or the binding of tRNA to the polysomal complex. Journal of Endocrinology (1989) 120, 83–88

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18

Rawlings, A. V., and T. Deegan. "Interference by Pro-Apolipoprotein A-I in Apolipoprotein E Phenotyping Using Chemical Precipitation Procedures." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 25, no. 6 (November 1988): 638–44. http://dx.doi.org/10.1177/000456328802500607.

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Lipoproteins of density, d < 1·063, isolated by polyanion-cation precipitation methods, gave isoelectric focussing patterns of apolipoprotein E isoforms by rod-gel electrophoresis which differed from the corresponding patterns obtained from ultracentrifugally-derived very low density lipoproteins. The differences were sporadic and variable but the most common effect was an increased frequency of the E3 isoform. Two-dimensional analyses involving sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Immunoelectrophoresis against anti-apolipoprotein A-I indicated that contamination of precipitated lipoproteins with pro-apolipoprotein A-I was responsible for this phenomenon. It is suggested that two-dimensional techniques should be applied for definitive phenotyping if precipitated lipoproteins are used as source material.

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19

Hattori, Masa-aki, Kazunori Ozawa, and Katsumi Wakabayashi. "Isoelectric properties, lectin binding characteristics and biological activities of neuraminidase-treated rat LH components." Acta Endocrinologica 117, no. 1 (January 1988): 73–79. http://dx.doi.org/10.1530/acta.0.1170073.

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Abstract. The present study was performed to evaluate the different carbohydrate structure of rat LH isoelectric components related to their intrinsic biological activities. Terminal sialic acid residues were essential to the formation of multiple LH components observed in the isoelectric focussing profile, which was proved by their interaction with Ricinus communis agglutinin-120 following neuraminidase treatment, and the conversion of component F (pI, 10.0) to less alkaline components after incubation with liver Golgi membrane fraction in the presence of CMP-NeuNAc. The affinity studies using lentil lectin indicated that component F was not an asialo form of component A (pI 8.4). The serial removal of sialic acid residues from these components led to increases in the steroidogenic activity, owing to increases in the activation of the receptor-adenylate cyclase system. The enhancement of the steroidogenic activity by desialylation was very great in component A'(pI, 8.0) (751% increase), and decreased with increasing pI. It can be concluded that the different biological potencies of intact LH components are attributable principally to terminal sialic acid residues. However, the peripheral chains of asialo oligosaccharides of less alkaline components (pI, 8.0, 8.4) seem to prevent the maximal cellular responses, since their desialylated forms did not attain the maximum activity.

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20

O'Neill, C. M., and R. J. Mathiasu. "A rapid and simple method of producing high-resolution zymograms from Brassica and related species on isoelectric-focussing gels." Plant Breeding 114, no. 2 (April 1995): 179–81. http://dx.doi.org/10.1111/j.1439-0523.1995.tb00787.x.

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21

Nauseef, WM, and HL Malech. "Analysis of the peptide subunits of human neutrophil myeloperoxidase." Blood 67, no. 5 (May 1, 1986): 1504–7. http://dx.doi.org/10.1182/blood.v67.5.1504.1504.

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Abstract Myeloperoxidase is a cationic protein present in the azurophilic granules of human neutrophils and constitutes 2% to 5% of neutrophil protein by weight. Despite extensive characterization of the functional importance of myeloperoxidase in the microbicidal activity of neutrophils, there is no consensus regarding the subunit composition of this enzyme or the presence of genetic polymorphism. Using isoelectric focussing and peptide mapping of chymotryptic digests of myeloperoxidase subunits under reducing and nonreducing conditions, we found two different heavy chain peptides that have overlapping but distinctive chymotryptic digest maps. One of these heavy chains has a reducible intrapeptide disulfide bond not found in the other. These results suggest that the model proposed for the structure of myeloperoxidase as a symmetric molecule with two identical heavy-light protomers may not be correct.

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22

Nauseef, WM, and HL Malech. "Analysis of the peptide subunits of human neutrophil myeloperoxidase." Blood 67, no. 5 (May 1, 1986): 1504–7. http://dx.doi.org/10.1182/blood.v67.5.1504.bloodjournal6751504.

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Myeloperoxidase is a cationic protein present in the azurophilic granules of human neutrophils and constitutes 2% to 5% of neutrophil protein by weight. Despite extensive characterization of the functional importance of myeloperoxidase in the microbicidal activity of neutrophils, there is no consensus regarding the subunit composition of this enzyme or the presence of genetic polymorphism. Using isoelectric focussing and peptide mapping of chymotryptic digests of myeloperoxidase subunits under reducing and nonreducing conditions, we found two different heavy chain peptides that have overlapping but distinctive chymotryptic digest maps. One of these heavy chains has a reducible intrapeptide disulfide bond not found in the other. These results suggest that the model proposed for the structure of myeloperoxidase as a symmetric molecule with two identical heavy-light protomers may not be correct.

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23

O'dowd, Brian F., Don Mahuran, Dale Cumming та J. Alexander Lowden. "Characterization by nuclear magnetic resonance of the concanavalin A binding oligosaccharide on the βb chain of placental β-hexosaminidase B: lectin binding to the separated polypeptide chains of hexosaminidases A and B". Canadian Journal of Biochemistry and Cell Biology 63, № 7 (1 липня 1985): 723–29. http://dx.doi.org/10.1139/o85-090.

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The type and distribution of the oligosaccharides on each polypeptide of human placental β-hexosaminidases A (α(βaβb)) and B (2((βaβb)) were examined. The denatured polypeptides were separated by isoelectric focussing in a polyacrylamide slab gel and each gel was then overlaid with 125I-labelled lectins. The study indicated that the βa chain contains negligible carbohydrate, the βb chain contains both the high-mannose and a complex type oligosaccharide, and the α chain contains predominantly high-mannose or hybrid type moieties. Two asparagine-linked high-mannose type oligosaccharides present on the βb polypeptide of β-hexosaminidase B were isolated by concanavalin A chromatography and by reverse-phase high pressure liquid chromatography. Proton nuclear magnetic resonance characterization of the oligosaccharides revealed an equimolar glycan mixture of the high-mannose type structure Man5 and Man6.

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24

Sahota, T. S., F. G. Peet, A. J. Thomson, and A. Ibaraki. "CHANGES IN HEMOLYMPH PROTEINS IN RELATION TO DORMANCY OF BARBARA COLFAXIANA KFT. AND THE INFLUENCE OF ECDYSONE AND PRECOCENE ON THE PROTEIN COMPOSITION." Canadian Entomologist 118, no. 9 (September 1986): 839–47. http://dx.doi.org/10.4039/ent118839-9.

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AbstractHemolymph proteins of the Douglas-fir cone moth, Barbara colfaxiana (Kft.), in the year of pupation (year P) and the next year (year P + 1) were studied by visual examination and analysis of digitized images of isoelectric focussing patterns. Differences in these proteins between light and dark individuals in year P and P + 1 were not related to dormancy duration but reflected the extent of pharate-adult development. Hormone applications were more effective in changing hemolymph proteins of light insects than those of dark ones. Changes in the hemolymph proteins of light insects in year P + 1 were not very obvious by visual examination of gels but were readily detectable by digital image analysis and showed that development occurred in these insects through June-September leading to visible pigmentation differences observable in relation to dormancy commitments of these insects.

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25

Ibrahim, Zaharah, Wan Azlina Ahmad, and Abu Bakar Baba. "Bioaccumulation of silver and the isolation of metal-binding protein from P.diminuta." Brazilian Archives of Biology and Technology 44, no. 3 (September 2001): 223–25. http://dx.doi.org/10.1590/s1516-89132001000300001.

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A silver uptake study by Pseudomonas diminuta was carried out by growing the bacteria in a chloride-free medium (CFM) containing silver ions (50 muM) in a batch culture. From the results, it was found that higher amounts of silver were accumulated inside the cell during early exponential phase compared to the amount bound at the cell surface. This suggested a possible mechanism for metal uptake during bacterial growth. In view of this, attempts were made to isolate proteins which might be associated with silver-binding properties from cultures of P.diminuta grown in the presence and absence of silver. The proteins were first extracted from the bacterial cultures by precipitation with ammonium sulfate followed by purification using isoelectric focussing and SDS-PAGE. Results of the experiment showed the presence of low molecular weight and high molecular weight proteins containing silver with pI values ranging from 2.0 to 9.0 for bacteria grown in the presence of silver.

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26

Welle, Roland, and Hans Grisebach. "Purification and Properties of Chalcone Synthase from Cell Suspension Cultures of Soybean." Zeitschrift für Naturforschung C 42, no. 11-12 (December 1, 1987): 1200–1206. http://dx.doi.org/10.1515/znc-1987-11-1211.

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Incubation of soybean cell suspension cultures in B-5 medium containing 0.4 ᴍ sucrose caused induction of chalcone synthase (CHS) up to a specific activity of 8 µkat/kg. CHS from these cultures was purified to apparent homogeneity by a 5-step procedure. Isoelectric focussing of pure CHS gave a major band at pH 5.45 and two weaker bands at pH 5.35 and 5.5. At least the bands at pH 5.35 and 5.45 had CHS activity. Analysis of pure CHS by two-dimensional electrophoresis gave a set ot six proteins with a M, of 40 kDa and pIs between 6.0 and 6.6. One-dimensional PAGE of CHS under non-denaturing conditions gave three closely spaced protein bands. A specific antibody was raised against soybean CHS which cross-reacted with parsley CHS. Attempts to find synthesis of deoxychalconc or of the corresponding 7.4′-dihydroxyflavanonc with CHS of different purification stages and with various cofactors failed.

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27

Westwood, J. Tim, Robert B. Church, and Emile B. Wagenaar. "Patterns of protein synthesis during the cell cycle of Chinese hamster ovary cells." Biochemistry and Cell Biology 65, no. 3 (March 1, 1987): 219–29. http://dx.doi.org/10.1139/o87-028.

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The protein synthesis patterns at various stages of the cell cycle of Chinese hamster ovary cells were examined by labelling cells with [35S]methionine and then separating the proteins by isoelectric focussing and two-dimensional, nonequilibrium pH gradient gel electrophoresis. We have observed a number of proteins which display quantitative differences in synthesis at specific cell cycle stages and of these the α- and β-tubulins have been identified. A few proteins appear to be uniquely synthesized at specific times during the cell cycle. These include the histones and a modified version of them, which are synthesized only in S phase, and a pair of 21 kilodalton (kDa), pI 5.5 proteins, which appear only in late G2 and mitosis. We have also identified a 58-kDa, pI 7.5 protein which is present at all cell cycle stages except during late G2. This protein appears to have the same temporal properties as a 57-kDa protein called "cyclin" originally described in sea urchin embryos.

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28

Marsigliante, S., V. A. Baker, J. Puddefoot, S. Barker, and G. P. Vinson. "4 S Oestrogen receptor isoforms and their distribution in breast cancer samples." Journal of Molecular Endocrinology 7, no. 3 (December 1991): 205–11. http://dx.doi.org/10.1677/jme.0.0070205.

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ABSTRACT The variability in the profile of oestrogen receptor (ER) isoforms in breast tumours has been studied. Using low-resolution isoelectric focussing (IEF), two major ER isoforms with isoelectric point (pI) values of 6.1 and 6.6 could be identified, with corresponding sedimentation coefficients in sucrose density gradients of 8 S and 4 S respectively. Using high-resolution IEF or immunoblotting, the pI 6.6 form (4S) was shown to be composed of three different species, with pI values of 6.3, 6.6 and 6.8, while the oligomeric pI 6.1 protein (8 S) did not show charge heterogeneity. Data were obtained on the soluble receptors from supernatants of 42 ER-positive primary breast tumour homogenates using high-resolution IEF to obtain ER isoform profiles. It was found that 54.7% of tumours contained the isoforms at pI 6.6 and 6.1, while only 11.9% contained the full complement of isoforms (pI 6.1, 6.3, 6.6 and 6.8). Of the tumours studied, 11.9% contained isoforms of pI 6.1, 6.6 and 6.8, with 14.3% containing isoforms with pI 6.1, 6.6 and 6.3. Very few tumours contained only one isoform, with 4.8% of tumours containing a single isoform at pI 6.1 and 2.4% of tumours containing only the isoform at pI 6.6. All four ER isoforms were also shown to be present in some tumours by immunoblotting using antibody H222 and, in addition, high-resolution IEF indicated that all isoforms bind oestradiol, diethylstilboestrol and tamoxifen. The variability in the ER isoform profile may have a bearing on the known variability of tumour response to endocrine therapy and prognosis.

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29

Shigeno, Chohei, Itsuo Yamamoto, Shegiharu Dokoh, Megumu Hino, Jun Aoki, Rikushi Morita, and Kanji Torizuka. "Co-purification of bone resorbing activity and adenylate cyclase stimulating activity from human tumours associated with the humoral hypercalcaemia of malignancy." Acta Endocrinologica 114, no. 1 (January 1987): 18–26. http://dx.doi.org/10.1530/acta.0.1140018.

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Abstract. We have partially purified a tumour factor capable of stimulating both bone resorption in vitro and cAMP accumulation in osteoblastic ROS 17/2 cells from three human tumours associated with humoral hypercalcaemia of malignancy. Purification of tumour factor by sequential acid urea extraction, gel filtration and cation-exchange chromatography, reverse-phase high performance liquid chromatography followed by analytical isoelectric focussing provided a basic protein (pI > 9.3) with a molecular weight of approximately 13 000 as a major component of the final preparation which retained both the two bioactivities. Bone resorbing activity and cAMP-increasing activity in purified factor correlated with each other. cAMP-increasing activity of the factor was heat- and acid-stable, but sensitive to alkaline ambient pH. Treatment with trypsin destroyed cAMP-increasing activity of the factor. Synthetic parathyroid hormone (PTH) antagonist, human PTH-(3– 34) completely inhibited the cAMP-increasing activity of the factor. The results suggest that this protein factor, having its effects on both osteoclastic and osteoblastic functions, may be involved in development of enhanced bone resorption in some patients with humoral hypercalcaemia of malignancy.

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30

Santoso, S., V. Kiefel, and C. Mueller-Eckhardt. "Blood Group A and B Determinants Are Expressed on Platelet Glycoproteins IIa, IIIa, and Ib." Thrombosis and Haemostasis 65, no. 02 (1991): 196–201. http://dx.doi.org/10.1055/s-0038-1647483.

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SummaryWe report the localization of A, B blood group determinants on intrinsic glycoproteins using anti-A, B IgG antibodies. By radioimmunoprecipitation, anti-A and anti-B precipitated three bands with apparent molecular masses in sodium dodecylsulphate- polyacrylamide gel electrophoresis (SDS-PAGE) of 159, ~ 120 and 85 kDa under non-reduced conditions and 145, ~ 126 and 97 kDa under reduced conditions. In two-dimensional gel electrophoresis (isoelectric focussing/SDS-PAGE) these three bands could be resolved into six spots and fulfilled previously defined citeria for platelet membrane glycoprotein complexes Ia/IIa, Ic’IIIa, Ib/IX and IIb/IIIa. The results were supported by data obtained by an assay employing antibody-specific immobilizatisn of platelet antigens (MAIPA). By this technique, blood group A, B determinants were shown to be immobilized by monoclonal antibodies specific for GPIa, Ic’, IX, IIb/IIIa and strongly by mab specific for GPIIa, but not by mab specific for HLA class I molecules.The more precise localization on platelet glycoproteins was achieved by immunoblotting technique by which blood group A determinants could be assigned to GPs IIa, IIIa and Ib.

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31

Pickard, Michael A., and Atsumi Hashimoto. "Stability and carbohydrate composition of chloroperoxidase from Caldariomyces fumago grown in a fructose–salts medium." Canadian Journal of Microbiology 34, no. 8 (August 1, 1988): 998–1002. http://dx.doi.org/10.1139/m88-175.

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The glycoprotein chloroperoxidase has been isolated from Caldariomyces fumago grown in a fructose-salts medium and some of its properties studied, including stability to pH and temperature and carbohydrate composition, as a preliminary to immobilization. At 22 °C, more than 50% of the activity remained after 15 days when the enzyme was maintained between pH 3.5 and 5.5; between pH 6 and 7 only 25% of activity remained after 4 days. At 40 °C and pH 5.5, enzyme activity was stable for 7 days. Carbohydrate composition studies were carried out on six isoenzymes of chloroperoxidase that were separated by isoelectric focussing on flat-bed Sephadex G-75 gels. After acid hydrolysis and derivatization, the carbohydrate components of the isoenzymes were analyzed by gas chromatography. The major components were found to be glucose and mannose, with xylose, galactose, and glucosamine present at levels less than 10% of the total. These results contrasted with those for the enzyme purified after growth of the fungus on glucose and malt extract, previously reported, where the carbohydrate components were identified as arabinose and glucosamine.

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32

Wyatt, Jane, Stephen May, Susan De Caigney, Peter George та Stephen Brennan. "Hypofibrinogenemia due to Novel 316 Asp → Tyr Substitution in the Fibrinogen Bβ Chain". Thrombosis and Haemostasis 85, № 03 (2001): 450–53. http://dx.doi.org/10.1055/s-0037-1615603.

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SummaryWe investigated the molecular basis of hypofibrinogenemia in a woman with a plasma fibrinogen of 1.0 mg/mL. After sequencing the coding region and intronic boundaries of all three fibrinogen genes a single heterozygous GACTAC mutation was identified at codon 316 of the B gene. This AspTyr substitution segregated with the hypofibrinogenemia in the only other affected family member. Examination by SDS-PAGE, isoelectric focussing, reverse phase chromatography and electrospray ionisation (ESI) mass spectrometery, failed to detect expression of the new B chain in purified plasma fibrinogen. The absence of the variant chain was confirmed by ESI tryptic mapping; while the [M + 1 H] and [M + 2 H] ions of the affected peptide (MGPTELLIEMEDWK) were clearly visible at 1,692 and 847 m/z, there were no new signals (1741 or 871 m/z) that would at indicate expression of the variant in plasma. Asp 316 and itschain homologue (Asp 252) are conserved in all known species and this is the first report of a mutation at either of these. The residue appears to be critical in maintaining the structure of the five stranded sheet that forms the dominant structural feature of the D domains.

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33

Sussman, N. L., R. Eliakim, D. Rubin, D. H. Perlmutter, K. DeSchryver-Kecskemeti, and D. H. Alpers. "Intestinal alkaline phosphatase is secreted bidirectionally from villous enterocytes." American Journal of Physiology-Gastrointestinal and Liver Physiology 257, no. 1 (July 1, 1989): G14—G23. http://dx.doi.org/10.1152/ajpgi.1989.257.1.g14.

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A fraction of intestinal alkaline phosphatase (IAP) is secreted into blood. To study this process, enzyme secretion was examined in a fetal (IRD-98) and a differentiated (Caco-2) intestinal cell line. Tissue-unspecific alkaline phosphatase (AP) activity in the IRD-98 cells increased 20-fold after addition of 1.5 mM sodium butyrate and 40 mM NaCl, but no AP activity was secreted into the medium. In contrast, newly synthesized IAP in Caco-2 cells was secreted into the medium. AP secretion increased with time and was inhibited by monensin. Medium AP was still partially bound to membranes as assessed by Triton X-114 phase separation and could be released by the addition of serum. Analysis by sodium dodecyl sulfate polyacrylamide gels and by isoelectric focussing showed that secreted AP gave a pattern similar to that of the AP released from membranes by phospholipase D treatment. When Caco-2 cells were grown on filters, AP activity was found in both basolateral (75%) and luminal (25%) media. These data demonstrate that the secretion of a particulate AP with extracellular release from the membrane can account for the appearance of the intestinal isozyme in both the serum and the lumen.

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34

Münzenberger, B., T. Otter, A. Polle, and D. Wüstrich. "Peroxidase and laccase activities in mycorrhizal and non-mycorrhizal fine roots of Norway spruce (Picea abies) and larch (Larix decidua)." Canadian Journal of Botany 75, no. 6 (June 1, 1997): 932–38. http://dx.doi.org/10.1139/b97-103.

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Peroxidase (EC 1.11.1.7) and laccase (EC 1.10.3.1) activities were determined in mycorrhizal and non-mycorrhizal main and lateral roots of Picea abies (L.) Karst. (Norway spruce) and Larix decidua Mill, (larch) and in mycelia of the ectomycorrhizal fungus Laccaria amethystea (Bull.) Murr. grown under axenic conditions. Peroxidase isozyme patterns were identified after isoelectric focussing. In both tree species, mycorrhizae contained the lowest, and laterals of noninoculated plants the highest, peroxidase activities. Pure mycelia of Laccaria amethystea contained considerable laccase activity but no peroxidase activity. Laccase activity was barely detected in noninoculated laterals of spruce, but was present in noninoculated laterals of larch and in main roots of Norway spruce and larch. Highest laccase activities were found in mycorrhizae of both tree species, indicating that most of the activity was derived from the fungus. Laterals of Norway spruce contained eight, and those of larch five, acidic peroxidase isozymes. In mycorrhizae of Norway spruce and larch, specific peroxidase isozymes with pI values of 4.5 and 6.2 and 5.8 and 6.0, respectively, were almost completely suppressed. The specific suppression of peroxidase suggests that the fungal symbiont is able to modify the host defence response in mature mycorrhizae. Key words: defence mechanism, laccase, mycorrhiza, peroxidase (isozymes), plant–fungus interaction.

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35

O'Cualain, Ronan DM, John E. Hyde, and Paul FG Sims. "A protein-centric approach for the identification of folate enzymes from the malarial parasite, Plasmodium falciparum, using OFFGEL™ solution-based isoelectric focussing and mass spectrometry." Malaria Journal 9, no. 1 (2010): 286. http://dx.doi.org/10.1186/1475-2875-9-286.

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36

Wall, Joanne C., and David S. Bailey. "Two-dimensional isoelectric focussing/sodium dodecyl sulphate polyacrylamide gel electrophoretic mapping and some molecular characteristics of the proteins of the adult guinea-pig small intestinal microvillus membrane." Biochimica et Biophysica Acta (BBA) - Biomembranes 815, no. 2 (May 1985): 175–83. http://dx.doi.org/10.1016/0005-2736(85)90286-x.

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37

Anderson, C. L., D. H. Ryan, R. J. Looney, and P. C. Leary. "Structural polymorphism of the human monocyte 40 kilodalton Fc receptor for IgG." Journal of Immunology 138, no. 7 (April 1, 1987): 2254–56. http://dx.doi.org/10.4049/jimmunol.138.7.2254.

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Abstract The 40 kD monocyte Fc receptor for IgG is capable of binding murine IgG1 and of supporting an IgG1 anti-T3 T lymphocyte proliferative response among approximately 80% of Caucasian individuals (responders), whereas the 40 kD Fc receptor on monocytes of the remaining individuals (nonresponders) is incapable of interacting with murine IgG1. By using a monoclonal antibody (mab IV3) that reacts with the 40 kD receptor, we found that the monocyte 40 kD receptors from responder and nonresponder individuals cannot be distinguished by either electrophoretic mobility on SDS-polyacrylamide gels, or by the number of receptors per cell as determined by indirect immunofluorescence. However, isoelectric focussing of the purified radioiodinated 40 kD receptor revealed that the monocyte receptor from all of four nonresponder individuals evaluated has a single distinctive pattern of multiple, regularly spaced bands, whereas the pattern of the 40 kD monocyte receptor from 11 responder individuals is of two sorts. One (seen in four of 11 responders) consists of multiple, regularly spaced bands that are asynchronous with the nonresponder pattern, and the other (seen in seven of 11 responders) consists of multiple bands that correspond in mobility to all of the bands of both of the other two patterns. The incidence of these three patterns suggests that the 40 kD Fc receptor is encoded by a single structural gene with two alleles, both of which are expressed.

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38

Edwards, Matthew, Fiona McKenzie, Stephen O'Callaghan, David Somerset, Phillip Woodford, Jillian Spilsbury, Michael Fietz, and Janice Fletcher. "Prenatal Diagnosis of congenital disorder of glycosylation type Ia (CDG-Ia) by cordocentesis and transferrin isoelectric focussing of serum of a 27-week fetus with non-immune hydrops." Prenatal Diagnosis 26, no. 10 (2006): 985–88. http://dx.doi.org/10.1002/pd.1543.

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39

Gärtner, Roland, Günther Bechtner, Walter Greil, Klaus Horn, and C. Renate Pickardt. "Characterization of microheterogencity of human thyroglobulin from different thyroid disorders." Acta Endocrinologica 109, no. 1 (May 1985): 76–82. http://dx.doi.org/10.1530/acta.0.1090076.

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Abstract. Human thyroglobulin (Tg) was isolated to apparent purity from various thyroid tissue samples obtained after surgery. Iodine and iodothyronine content of Tg was determined. Isoelectric focussing (IEF) was performed on thin layer agarose gels. Tg revealed a microheterogeneity of 6 bands in the range between pH 4.2 and 4.6. The intensity of the single bands depended on the iodothyronine content of Tg. With increasing degree of iodination, the bands with a lower pI (pI 4.35, 4.40) became more prominent, whereas the bands with higher pI (pI 4.55, 4.60) diminished. This typical change in microheterogeneity pattern could be confirmed by kinetic in vitro iodination and consecutive iodothyronine formation of low iodinated Tg (0.05% iodine). After in vitro desialylation, the bands shifted to a higher pH range (pH 4.60 to pH 4.90), but no reduction of the number of bands occurred. Even in desialylated Tg microheterogeneity is still dependent on iodine content. These results suggest, that the microheterogeneity of Tg is influenced, but not caused by different iodine and NANA content. Different polypeptide composition may be responsible for the microheterogeneity of Tg. In thyroid diseases without disturbance in Tg synthesis (endemic, diffuse and nodular goitre, Graves' disease) variations in relative intensity of single bands could be related to differences in iodine content. In thyroid cyst fluid and cold nodules in addition to low iodinated Tg, further bands were found with pI-values comparable to desialylated Tg.

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40

van Ginkel, L. A., та J. G. Loeber. "Heterogeneity of human luteinizing hormone. Detection and identification of α- and β-subunits in international reference preparations". Acta Endocrinologica 114, № 4 (квітень 1987): 572–76. http://dx.doi.org/10.1530/acta.0.1140572.

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Abstract. The charge heterogeneity of three international reference preparations containing biologically active human luteinizing hormone (LH) or its free α-or β-subunits, respectively, was investigated with isoelectric focussing in sucrose density gradients. The immunoreactive profiles throughout the pH-gradient were assessed with radioimmunoassay (RIA) systems specific for intact, i.e. undissociated, LH or free α- or β-subunits. For the preparation of intact LH (MRC 68/40), two peaks were found at pH = 7.69 and 8.05; for the α-subunit preparation (NIBSC 78/554), the peak values were 4.76, 5.04, 5.94, 6.70, 6.96, 7.35, 8.02, 8.72 and 9.32; and for the β-subunit preparation (NIBSC 78/556), the values were 7.60, 8.40, 8.55 and 9.61. These results are in excellent agreement with those obtained for a highly purified LH preparation (NM 14) which was prepared by one of us and on which we have reported earlier. In addition, with the abovementioned techniques, the spontaneous dissociation of MRC 68/40 into subunits upon incubation at 37°C in phosphate buffer was clearly demonstrated by the increased immunoreactivity in the profiles assessed with both RIA-subunit systems. It is concluded that charge heterogeneity of LHi, α- and β-subunits, as observed for different preparations, is confined to a limited population of forms. Differences between preparations are only quantitative. A single preparation, therefore, can be used as a general model for the study of human luteinizing hormone.

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41

Harris, H., and S. E. Zalik. "Studies on the endogenous galactose-binding lectin during early development of the embryo of Xenopus laevis." Journal of Cell Science 79, no. 1 (November 1, 1985): 105–17. http://dx.doi.org/10.1242/jcs.79.1.105.

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Embryos of the frog Xenopus laevis at cleavage, blastula, gastrula and neurula stages contain a galactose-specific lectin. Extracts of gastrula embryos show the highest specific activity for this lectin compared to the other stages. Haemagglutinating activity of crude extracts is inhibited by lactose, alpha-galactose, beta-galactose, alpha Gal(1----4) beta Gal, beta Gal(1----3) alpha GalNAc, beta Gal(1----3) beta GlcNAc, beta Gal (1----4) beta GlcNAc, and most effectively by the disaccharide alpha Gal(1----3) beta Gal. Lectin from all stages was purified by absorption to galactose-linked immunoadsorbent or by affinity chromatography on a column of p-aminophenyl-beta-D-lactoside coupled to Sepharose 4B. In order to identify a single lectin band under reducing conditions in sodium dodecyl sulphate/polyacrylamide electrophoresis SDS/PAGE, it was necessary to treat aqueous suspensions of the purified lectin with chloroform/methanol (2:1, v/v). The lectin remained in the aqueous layer and gave rise on SDS/PAGE to a distinct band of 65 500 +/− 2780 molecular weight. Aqueous suspensions of the purified lectin that were not subjected to extraction with chloroform/methanol gave rise to several bands. Isoelectric focussing of the purified lectin resulted in two bands that separated at pI 4.3 and 4.5. In aqueous solution in the presence of lactose the chloroform/methanol-treated lectin appears to be an aggregate of apparent molecular weight of 375 000; the non-treated lectin under the same conditions has an apparent molecular weight of 490 000.

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42

Steffen, W., E. A. Fajer, and R. W. Linck. "Centrosomal components immunologically related to tektins from ciliary and flagellar microtubules." Journal of Cell Science 107, no. 8 (August 1, 1994): 2095–105. http://dx.doi.org/10.1242/jcs.107.8.2095.

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Centrosomes are critical for the nucleation and organization of the microtubule cytoskeleton during both interphase and cell division. Using antibodies raised against sea urchin sperm flagellar microtubule proteins, we characterize here the presence and behavior of certain components associated with centrosomes of the surf clam Spisula solidissima and cultured mammalian cells. A Sarkosyl detergent-resistant fraction of axonemal microtubules was isolated from sea urchin sperm flagella and used to produce monoclonal antibodies, 16 of which were specific- or cross-specific for the major polypeptides associated with this microtubule fraction: tektins A, B and C, acetylated alpha-tubulin, and 77 and 83 kDa polypeptides. By 2-D isoelectric focussing/SDS polyacrylamide gel electrophoresis the tektins separate into several polypeptide spots. Identical spots were recognized by monoclonal and polyclonal antibodies against a given tektin, indicating that the different polypeptide spots are isoforms or modified versions of the same protein. Four independently derived monoclonal anti-tektins were found to stain centrosomes of S. solidissima oocytes and CHO and HeLa cells, by immunofluorescence microscopy. In particular, the centrosome staining of one monoclonal antibody specific for tektin B (tekB3) was cell-cycle-dependent for CHO cells, i.e. staining was observed only from early prometaphase until late anaphase. By immuno-electron microscopy tekB3 specifically labeled material surrounding the centrosome, whereas a polyclonal anti-tektin B recognized centrioles as well as the centrosomal material throughout the cell cycle. Finally, by immunoblot analysis tekB3 stained polypeptides of 48–50 kDa in isolated spindles and centrosomes from CHO cells.

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43

Olofsson, Anders, Hans Hebert, Urban Kavéus та Monica Thelestam. "Staphylococcus aureus α-Toxin Crystals on Lipid Layers: Effects of Trypsin Treatment". Proceedings, annual meeting, Electron Microscopy Society of America 48, № 1 (12 серпня 1990): 106–7. http://dx.doi.org/10.1017/s0424820100179282.

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α-toxin is a lethal, dermonecrotic, cytotoxic, and hemolytic protein which is secreted by most strains of Staphylococcus aureus . The biological effects are brought about by pertubation of membrane structures making them permeable to ions and small molecules. The structural basis for the mode of action is not known in detail. One hypothesis is that an oligomeric form of the toxin, observed both biochemically and by electron microscopy, circumscribe a hydrophilic pore through which transport can occur. Recent functional studies have demonstrated that oligomerization is a necessary but not a sufficient criterion for permeabilization. For example, trypsin treated α-toxin was, despite its lack of membrane damaging activity, able to form 200 kDa aggregates on mouse adrenocortical (Yl) tumor cells. In this work we have compared the structure of trypsin treated α-toxin with that of the intact toxin.α-toxin was purified from S. aureus strain wood 46 by isoelectric focussing and gel filtration. Tryptic toxin fragments (18 and 17 kD as determined by SDS-PAGE) were generated by digestion of native α-toxin (1 mg in 1.5 ml Tris buffered saline) with 30μg trypsin for 4 h at 37°C, pH 8.0. The reaction was terminated by the addition of 30μg lima beam trypsin inhibitor. Toxin specimens were applied to lipid layers pre-formed on carbon support films. Electron microscopy was performed after negative staining either with 1% Na-PTA (pH 7.0) or with a mixture of Na-PTA and glucose. Subsequent image processing of large coherent crystalline arrays produced correlation averaged projection maps. A three-dimensional model was obtained by collecting and combining data from tilted views.

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44

Prost, Josiane, Jacques Belleville, and Carole Valantin-Rollet. "Effects of age, and protein malnutrition followed by a balanced diet on the non-parallel change in digestive enzymes in the pancreas and their secretion in the rat." British Journal of Nutrition 60, no. 3 (November 1988): 619–31. http://dx.doi.org/10.1079/bjn19880132.

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1. Ninety male Wistar rats were divided into two groups. A control group (C) was fed on a balanced diet, containing 200 g protein/kg for 51 d. An experimental group (E) was fed on a low-protein diet containing 50 g protein/kg for 28 d (PM), and then on a balanced diet for 23 d (BR). At different days of PM and BR, the pancreas and the pancreatic juice were collected 40 min after injection of 0.1 mCi [3H]leucine. The amounts of amylase (EC3.2.1.1), trypsinogen 2 (EC3.4.21.4), chymotrypsinogen 1 (EC3.4.21.1) and lipase (EC3.1.1.3) were determined after separation by the isoelectric focussing technique. Incorporation of [3H]leucine into the four hydrolases of pancreatic juice and pancreas was also determined.2. In control rats a progressive increase in the concentration of digestive enzymes and the amounts secreted were observed with age. Maturation was reached when the rats were 9 weeks old. In rats E, PM inhibited maturation of the pancreas. However, individual enzymes were not affected to the same extent and at the same time. As soon as re-feeding was initiated, pancreas maturation took place and a significant increase in these variables was observed. The increases varied according to the hydrolase and did not appear at the same time.3. In control rats, a preferential secretion of newly synthesized enzymes was observed in young rats, whereas with age, the proportion of newly synthesized enzymes excreted decreased slowly. In group E rats, at the beginning of PM, the proportion of newly synthesized enzymes secreted was very low and increased with time.4. In rats C and E, our results indicated a non-parallelism between pancreatic enzyme levels and amounts secreted. This non-parallelism was different in both groups, it was changed with age and pancreas maturation in group C, and according to nutritional state in group E.

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45

"4495279 Isoelectric focussing-polynucleotide/polyacrylamide gel electrophoresis." Biotechnology Advances 3, no. 1 (January 1985): 99–100. http://dx.doi.org/10.1016/0734-9750(85)90069-2.

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46

Luckenbach, Christine, R. Wahl, and E. Kallee. "Isoelectric Focussing of Human Thyroxine Binding Globulin (Thyropexin) and Human Prealbumin (Transthyretin)." Clinical Chemistry and Laboratory Medicine 30, no. 7 (1992). http://dx.doi.org/10.1515/cclm.1992.30.7.387.

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47

Azulay, David-Olivier D., Hendrik Neubert, and Mireia Fernández Ocaña. "Visualisation tool for peptide fractionation data in proteomics: application to OFFGEL isoelectric focussing." BMC Bioinformatics 11, no. 1 (July 5, 2010). http://dx.doi.org/10.1186/1471-2105-11-371.

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48

Neubauer, H., K. Sotlar, A. Nordheim, A. Schrattenholz, M. Cahill, D. Wallwiener, E. Solomayer, and T. Fehm. "Breast cancer proteomics by laser capture microdissection, sample pooling, 54 cm immobilised pH gradient isoelectric focussing, and differential iodine radioisotope detection." Geburtshilfe und Frauenheilkunde 66, S 01 (September 19, 2006). http://dx.doi.org/10.1055/s-2006-952350.

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