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Journal articles on the topic 'Helical Dichroism'

Author: Grafiati

Published: 30 June 2021

Last updated: 2 February 2022

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1

Xie, Yun Zhi, Chun Hua Liu, Xun Li, Yi Bao Li, and Xiao Lin Fan. "Asymmetry-Induced Supramolecular Helices of Pyrene-Perylene Bisimide Triads." Advanced Materials Research 472-475 (February 2012): 462–65. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.462.

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The formation of helical nanostructure is investigated for donor/acceptor system. The helices of the supramolecular nanofibres can be revealed by atom force microscope (AFM) and circular dichroism (CD) measurement. The expermental results show the Py-Per-Py can self assembly into helical nanofibres. The controlled experiments on the compound Py-e-Per-e-Py with symmetrical conformation indicates the formation of helical nanofibres may be attributed to asymmetrical conformation.

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2

Miles, A. J., and B. A. Wallace. "Circular dichroism spectroscopy of membrane proteins." Chemical Society Reviews 45, no. 18 (2016): 4859–72. http://dx.doi.org/10.1039/c5cs00084j.

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3

Liu, Yong, Chao Li, Yaling Liu, and Zhiyong Tang. "Helical silver(I)-glutathione biocoordination polymer nanofibres." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, no. 2000 (October 13, 2013): 20120307. http://dx.doi.org/10.1098/rsta.2012.0307.

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Helical nanofibres of silver(I)-glutathione (Ag-GSH) biocoordination polymer (BCP) are fabricated by introducing dimethyl sulfoxide into the mixture solution of Ag + ions and l -GSH molecules. The prepared BCP nanofibres show hierarchical helical structures, which are constructed via twisting of small fibres. Water-soluble helices could be further cross-linked with Ca 2+ ions to form a well-dispersed aqueous suspension. When gold nanorods are adsorbed onto these helical nanofibres, the unique plasmon-induced circular dichroism characteristic is observed in the region of the local surface plasmon resonance of gold nanorods. This type of chiroptical metamaterials may have promising applications in nonlinear optics, negative refraction and biosensing.

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4

Daly, Steven, Frédéric Rosu, and Valérie Gabelica. "Mass-resolved electronic circular dichroism ion spectroscopy." Science 368, no. 6498 (June 25, 2020): 1465–68. http://dx.doi.org/10.1126/science.abb1822.

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DNA and proteins are chiral: Their three-dimensional structures cannot be superimposed with their mirror images. Circular dichroism spectroscopy is widely used to characterize chiral compounds, but data interpretation is difficult in the case of mixtures. We recorded the electronic circular dichroism spectra of DNA helices separated in a mass spectrometer. We studied guanine-rich strands having various secondary structures, electrosprayed them as negative ions, irradiated them with an ultraviolet nanosecond optical parametric oscillator laser, and measured the difference in electron photodetachment efficiency between left and right circularly polarized light. The reconstructed circular dichroism ion spectra resembled those of their solution-phase counterparts, thereby allowing us to assign the DNA helical topology. The ability to measure circular dichroism directly on biomolecular ions expands the capabilities of mass spectrometry for structural analysis.

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5

Kaschke, Johannes, and Martin Wegener. "Optical and Infrared Helical Metamaterials." Nanophotonics 5, no. 4 (September 1, 2016): 510–23. http://dx.doi.org/10.1515/nanoph-2016-0005.

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AbstractBy tailoring metamaterials with chiral unit cells, giant optical activity and strong circular dichroism have been achieved successfully over the past decade. Metamaterials based on arrays of metal helices have revolutionized the field of chiral metamaterials, because of their capability of exhibiting these pronounced chiro-optical effects over previously unmatched bandwidths. More recently, a large number of new metamaterial designs based on metal helices have been introduced with either optimized optical performance or other chiro-optical properties for novel applications.The fabrication of helical metamaterials is, however, challenging and even more so with growing complexity of the metamaterial designs. As conventional two-dimensional nanofabrication methods, for example, electron-beam lithography, are not well suited for helical metamaterials, the development of novel three-dimensional fabrication approaches has been triggered.Here, we will discuss the theory for helical metamaterials and the principle of operation. We also review advancements in helical metamaterial design and their limitations and influence on optical performance. Furthermore, we will compare novel nano- and microfabrication techniques that have successfully yielded metallic helical metamaterials. Finally, we also discuss recently presented applications of helical metamaterials extending beyond the use of far-field circular polarizers.

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6

Ala, Paul, Pele Chong, Vettai S. Ananthanarayanan, Neville Chan, and Daniel S. C. Yang. "Synthesis and characterization of a fragment of an ice nucleation protein." Biochemistry and Cell Biology 71, no. 5-6 (May 1, 1993): 236–40. http://dx.doi.org/10.1139/o93-036.

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Synthetic peptides were used as models for studying the conformation of ice nucleation proteins. We chemically synthesized four peptides (16-, 24-, 32-, and 48-mer) that consisted of two to six repeats of the consensus repeating octapeptide unit of ice nucleation proteins and evaluated their conformation by circular dichroism spectroscopy. These model peptides exist predominantly as random coils in aqueous solution, but adopt α-helical structures in the presence of trifluoroethanol. The stability of their secondary structures was investigated by monitoring the pH and time dependence of their circular dichroism spectra. Our results indicated that the α-helical content of the 48-mer exhibited a significant pH dependence, while that of the 24- and 32-mer peptides did not. The 32-mer was the only peptide that transformed from the α-helical to a β-sheet structure upon storage. We suggest that the overall conformation of the ice nucleation protein could be a β-sheet.Key words: ice nucleation protein, synthetic peptides, circular dichroism.

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7

Axelsen, P. H., B. K. Kaufman, R. N. McElhaney, and R. N. Lewis. "The infrared dichroism of transmembrane helical polypeptides." Biophysical Journal 69, no. 6 (December 1995): 2770–81. http://dx.doi.org/10.1016/s0006-3495(95)80150-5.

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8

Rabenold, David A. "Circular dichroism band shapes for helical polymers." Journal of Physical Chemistry 92, no. 17 (August 1988): 4863–68. http://dx.doi.org/10.1021/j100328a013.

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9

Kodaka, Masato. "Circular dichroism induced by helical host molecules." Journal of the Chemical Society, Faraday Transactions 93, no. 11 (1997): 2057–59. http://dx.doi.org/10.1039/a700222j.

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10

Kaerkitcha, N., and T. Sagawa. "Amplified polarization properties of electrospun nanofibers containing fluorescent dyes and helical polymer." Photochemical & Photobiological Sciences 17, no. 3 (2018): 342–51. http://dx.doi.org/10.1039/c7pp00413c.

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Well-aligned nanofibers containing cationic fluorescent dyes and anionic chiral polymers prepared via electrospinning exhibit an enhanced circular dichroism, which is mainly caused by linear dichroism and linear birefringence.

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11

Liang, Kaichang, Lichao Dong, Na Jin, Didi Chen, Xiao Feng, Jianbing Shi, Junge Zhi, Bin Tong, and Yuping Dong. "The synthesis of chiral triphenylpyrrole derivatives and their aggregation-induced emission enhancement, aggregation-induced circular dichroism and helical self-assembly." RSC Advances 6, no. 28 (2016): 23420–27. http://dx.doi.org/10.1039/c5ra26985g.

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12

Li, Hongkun, Juan Cheng, Yihua Zhao, Jacky W. Y. Lam, Kam Sing Wong, Hongkai Wu, Bing Shi Li, and Ben Zhong Tang. "l-Valine methyl ester-containing tetraphenylethene: aggregation-induced emission, aggregation-induced circular dichroism, circularly polarized luminescence, and helical self-assembly." Mater. Horiz. 1, no. 5 (2014): 518–21. http://dx.doi.org/10.1039/c4mh00078a.

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13

Xue, Shan, Luming Meng, Rongsen Wen, Lin Shi, Jacky W. Lam, Zhiyong Tang, Bing Shi Li, and Ben Zhong Tang. "Unexpected aggregation induced circular dichroism, circular polarized luminescence and helical assembly from achiral hexaphenylsilole (HPS)." RSC Advances 7, no. 40 (2017): 24841–47. http://dx.doi.org/10.1039/c7ra02495a.

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14

Rabenold, David A., and William Rhodes. ".alpha.-Helical polypeptide circular dichroism component band analysis." Journal of Physical Chemistry 90, no. 12 (June 1986): 2560–66. http://dx.doi.org/10.1021/j100403a004.

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15

Botek, Edith, and Benoît Champagne. "Circular dichroism of helical structures using semiempirical methods." Journal of Chemical Physics 127, no. 20 (November 28, 2007): 204101. http://dx.doi.org/10.1063/1.2805395.

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16

Miyahara, Shin, and Nobuo Furukawa. "Nonreciprocal Directional Dichroism and Toroidalmagnons in Helical Magnets." Journal of the Physical Society of Japan 81, no. 2 (February 15, 2012): 023712. http://dx.doi.org/10.1143/jpsj.81.023712.

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17

Wang, Heng, Adriana Pietropaolo, Wenbin Wang, Chen-Yi Chou, Ichiro Hisaki, Norimitsu Tohnai, Mikiji Miyata, and Tamaki Nakano. "Right-handed 2/1 helical arrangement of benzene molecules in cholic acid crystal established by experimental and theoretical circular dichroism spectroscopy." RSC Advances 5, no. 122 (2015): 101110–14. http://dx.doi.org/10.1039/c5ra20853j.

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18

Shanmugam, Ganesh, Prasad L. Polavarapu, Amy Kendall, and Gerald Stubbs. "Structures of plant viruses from vibrational circular dichroism." Journal of General Virology 86, no. 8 (August 1, 2005): 2371–77. http://dx.doi.org/10.1099/vir.0.81055-0.

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Vibrational circular dichroism (VCD) spectra in the amide I and II regions have been measured for viruses for the first time. VCD spectra were recorded for films prepared from aqueous buffer solutions and also for solutions using D2O buffers at pH 8. Investigations of four filamentous plant viruses, Tobacco mosaic virus (TMV), Papaya mosaic virus, Narcissus mosaic virus (NMV) and Potato virus X (PVX), as well as a deletion mutant of PVX, are described in this paper. The film VCD spectra of the viruses clearly revealed helical structures in the virus coat proteins; the nucleic acid bases present in the single-stranded RNA could also be characterized. In contrast, the solution VCD spectra showed the characteristic VCD bands for α-helical structures in the coat proteins but not for RNA. Both sets of results clearly indicated that the coat protein conformations are dominated by helical structures, in agreement with earlier reports. VCD results also indicated that the coat protein structures in PVX and NMV are similar to each other and somewhat different from that of TMV. The present study demonstrates the feasibility of measuring VCD spectra for viruses and extracting structural information from these spectra.

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19

Brullot, Ward, Maarten K. Vanbel, Tom Swusten, and Thierry Verbiest. "Resolving enantiomers using the optical angular momentum of twisted light." Science Advances 2, no. 3 (March 2016): e1501349. http://dx.doi.org/10.1126/sciadv.1501349.

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Circular dichroism and optical rotation are crucial for the characterization of chiral molecules and are of importance to the study of pharmaceutical drugs, proteins, DNA, and many others. These techniques are based on the different interactions of enantiomers with circularly polarized components of plane wave light that carries spin angular momentum (SAM). For light carrying orbital angular momentum (OAM), for example, twisted or helical light, the consensus is that it cannot engage with the chirality of a molecular system as previous studies failed to demonstrate an interaction between optical OAM and chiral molecules. Using unique nanoparticle aggregates, we prove that optical OAM can engage with materials’ chirality and discriminate between enantiomers. Further, theoretical results show that compared to circular dichroism, mainly based on magnetic dipole contributions, the OAM analog helical dichroism (HD) is critically dependent on fundamentally different chiral electric quadrupole contributions. Our work opens new venues to study chirality and can find application in sensing and chiral spectroscopy.

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20

Wang, Lei, and Luogen Deng. "Plasmonic Circular Dichroism of the Helical Nanosphere Assemblies and the Helical Nanoellipsoid Assemblies." Plasmonics 10, no. 2 (November 15, 2014): 399–409. http://dx.doi.org/10.1007/s11468-014-9821-1.

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21

Kefala, Aikaterini, Maria Amprazi, Efstratios Mylonas, Dina Kotsifaki, Mary Providaki, Charalambos Pozidis, Melina Fotiadou, and Michael Kokkinidis. "Probing Protein Folding with Sequence-Reversed α-Helical Bundles." International Journal of Molecular Sciences 22, no. 4 (February 16, 2021): 1955. http://dx.doi.org/10.3390/ijms22041955.

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Recurrent protein folding motifs include various types of helical bundles formed by α-helices that supercoil around each other. While specific patterns of amino acid residues (heptad repeats) characterize the highly versatile folding motif of four-α-helical bundles, the significance of the polypeptide chain directionality is not sufficiently understood, although it determines sequence patterns, helical dipoles, and other parameters for the folding and oligomerization processes of bundles. To investigate directionality aspects in sequence-structure relationships, we reversed the amino acid sequences of two well-characterized, highly regular four-α-helical bundle proteins and studied the folding, oligomerization, and structural properties of the retro-proteins, using Circular Dichroism Spectroscopy (CD), Size Exclusion Chromatography combined with Multi-Angle Laser Light Scattering (SEC-MALS), and Small Angle X-ray Scattering (SAXS). The comparison of the parent proteins with their retro-counterparts reveals that while the α-helical character of the parents is affected to varying degrees by sequence reversal, the folding states, oligomerization propensities, structural stabilities, and shapes of the new molecules strongly depend on the characteristics of the heptad repeat patterns. The highest similarities between parent and retro-proteins are associated with the presence of uninterrupted heptad patterns in helical bundles sequences.

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22

Zhao, Chunhui, Kunbing Ouyang, Jin Zhang, and Nianfa Yang. "Synthesis and properties of optically active helical polymers from (S)-3-functional-3′-vinyl-BINOL derivatives." RSC Advances 6, no. 47 (2016): 41103–7. http://dx.doi.org/10.1039/c6ra08146k.

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Helical vinyl polymers bearing N-heterocycles substituent BINOL derivatives were synthesized. The specific optical rotation and circular dichroism spectra data show the obtained polymers can keep a prevailing helicity of backbone in solution.

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23

Rabenold, David A. "Circular dichroism of helical polymers: a short-wavelength formulation." Journal of Physical Chemistry 94, no. 16 (August 1990): 6171–75. http://dx.doi.org/10.1021/j100379a007.

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24

Baimuratov, Anvar S., Tatiana P. Pereziabova, Nikita V. Tepliakov, Mikhail Yu Leonov, Alexander V. Baranov, Anatoly V. Fedorov, and Ivan D. Rukhlenko. "Electric-field-enhanced circular dichroism of helical semiconductor nanoribbons." Optics Letters 44, no. 3 (January 16, 2019): 499. http://dx.doi.org/10.1364/ol.44.000499.

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25

Christofi, Aristi, and Nikolaos Stefanou. "Strong magnetochiral dichroism of helical structures of garnet particles." Optics Letters 38, no. 22 (November 6, 2013): 4629. http://dx.doi.org/10.1364/ol.38.004629.

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26

Song, Chengyi, Martin G. Blaber, Gongpu Zhao, Peijun Zhang, H. Christopher Fry, George C. Schatz, and Nathaniel L. Rosi. "Tailorable Plasmonic Circular Dichroism Properties of Helical Nanoparticle Superstructures." Nano Letters 13, no. 7 (June 24, 2013): 3256–61. http://dx.doi.org/10.1021/nl4013776.

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27

Stevenson, Warren D., Xiangbing Zeng, Chris Welch, Anil K. Thakur, Goran Ungar, and Georg H. Mehl. "Macroscopic chirality of twist-bend nematic phase in bent dimers confirmed by circular dichroism." Journal of Materials Chemistry C 8, no. 3 (2020): 1041–47. http://dx.doi.org/10.1039/c9tc05061b.

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Long-range global chirality is confirmed in the twist-bend nematic phase of bent dimers using circular dichroism spectroscopy. The phase absorbs left and right circularly polarized light differently, confirming its helical rather than wavy character.

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28

Zheng, Xiu-Ying, Han Zhang, Ling-Yun Cao, Xiang-Jian Kong, La-Sheng Long, and Lan-Sun Zheng. "Chirality detection of two enantiomorphic 3D lanthanide coordination polymers by vibrational circular dichroism spectra." Dalton Transactions 44, no. 12 (2015): 5299–302. http://dx.doi.org/10.1039/c5dt00404g.

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Two enantiomorphic 3D lanthanide coordination polymers with chiral helical chains were synthesized based on an achiral ligand. The absolute configurations of the two structures were evidenced by the observation of strong signals in vibrational circular dichroism (VCD) spectra.

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29

Lees, J. G., and B. A. Wallace. "Synchrotron radiation circular dichroism and conventional circular dichroism spectroscopy: A comparison." Spectroscopy 16, no. 3-4 (2002): 121–25. http://dx.doi.org/10.1155/2002/280646.

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Conventional circular dichroism (cCD) spectroscopy is a valuable tool for secondary structure analyses of proteins. In recent years, it has been possible to use synchrotrons as light sources for CD, with the technique being known as Synchrotron Radiation Circular Dichroism (SRCD). In this study, the spectra of two proteins, the primarily helical myoglobin and the primarily beta‒sheet concanavalin A, have been collected on both a cCD instrument and on the SRCD at the Daresbury synchrotron and their characteristics were compared. Over the wavelength regions where both instruments are capable of making measurements (from about 300 to 175 nm) the spectra are very similar, except at the low wavelength extreme of the cCD spectra. In this region, the spectra deviate somewhat, due to the limitations of the light source intensity in the conventional instrument. The SRCD spectra extend to much lower wavelengths (160 nm). This additional low wavelength vacuum ultraviolet (VUV) data contains a large amount of extra information, including, for the first time, a number of peaks consistent with previously predicted charge transfer transitions.

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30

SUDHA, T. S., E. K. S. VIJAYAKUMAR, and P. BALARAM. "Circular dichroism studies of helical oligopeptides: Can 310 and α-helical conformations be chiroptically distinguished?" International Journal of Peptide and Protein Research 22, no. 4 (January 12, 2009): 464–68. http://dx.doi.org/10.1111/j.1399-3011.1983.tb02116.x.

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31

Saxena, Sarika, Satoru Nagatoishi, Daisuke Miyoshi, and Naoki Sugimoto. "Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions." Journal of Nucleic Acids 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/392039.

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In an ATP-dependent reaction, theEscherichia coliRecG helicase unwinds DNA junctionsin vitro. We present evidence of a unique protein conformational change in the RecG helicase from anα-helix to aβ-strand upon an ATP binding under dilute conditions using circular dichroism (CD) spectroscopy. In contrast, under molecular crowding conditions, theα-helical conformation was stable even upon an ATP binding. These distinct conformational behaviors were observed to be independent of Na+and Mg2+. Interestingly, CD measurements demonstrated that the spectra of a frayed duplex decreased with increasing of the RecG concentration both under dilute and molecular crowding conditions in the presence of ATP, suggesting that RecG unwound the frayed duplex. Our findings raise the possibility that theα-helix andβ-strand forms of RecG are a preactive and an active structure with the helicase activity, respectively.

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32

Chen, Jing, Songmei Li, Juan Du, Bo Wang, Shiming Meng, Jianhua Liu, and Mei Yu. "Optically active multi-helical erythrocyte-like Ln(OH)CO3 (Ln = La, Ce, Pr and Sm)." Physical Chemistry Chemical Physics 18, no. 30 (2016): 20261–65. http://dx.doi.org/10.1039/c6cp02302a.

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Hierarchical erythrocyte-like Ln(OH)CO₃ with nanosized chiral structure-induced circular dichroism responses, assigned to valence to conduction band transitions and coupling effects between the left-handed-assembled Ln(OH)CO₃ nanorods in the multi-helical RBC-like architecture.

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33

Hu, Jingpei, Xiaonan Zhao, Ruibin Li, Aijiao Zhu, Linghua Chen, Yu Lin, Bing Cao, Xiaojun Zhu, and Chinhua Wang. "Broadband circularly polarizing dichroism with high efficient plasmonic helical surface." Optics Express 24, no. 10 (May 11, 2016): 11023. http://dx.doi.org/10.1364/oe.24.011023.

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34

Müller, Dirk, Marc Böhme, Martin Nieger, Kari Rissanen, and Fritz Vögtle. "Helical thiaza[2.2]metacyclophanes. Synthesis, structure, circular dichroism, absolute configuration." J. Chem. Soc., Perkin Trans. 1, no. 24 (1996): 2937–43. http://dx.doi.org/10.1039/p19960002937.

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35

Tobata, H., and T. Sagawa. "Specific excitonic interactions in the aggregates of hyaluronic acid and cyanine dyes with different lengths of methine group." Photochemical & Photobiological Sciences 15, no. 3 (2016): 329–33. http://dx.doi.org/10.1039/c5pp00343a.

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The absorption and circular dichroism (CD) spectra of three types of cyanine dyes with different lengths of methine group (3,3′-diethylthiadicarbocyanine iodide, DTDC; 3,3′-diethylthiacarbocyanine iodide, DTC; and 3,3′-diethylthiacyanine iodide, DTTHC) in an aqueous solution were compared with and without hyaluronic acid (HA), which has a helical structure.

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36

GÖKOĞLU, GÖKHAN, and TARIK ÇELİK. "ALPHA-HELIX FORMATION IN C-PEPTIDE RNASE-A INVESTIGATED BY PARALLEL TEMPERING SIMULATIONS." International Journal of Modern Physics C 18, no. 01 (January 2007): 91–98. http://dx.doi.org/10.1142/s0129183107010292.

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We have performed parallel tempering simulations of a 13-residue peptide fragment of ribonuclease-A, c-peptide, in implicit solvent with constant dielectric permittivity. This peptide has a strong tendency to form α-helical conformations in solvent as suggested by circular dichroism (CD) and nuclear magnetic resonance (NMR) experiments. Our results demonstrate that 5th and 8–12 residues are in the α-helical region of the Ramachandran map for global minimum energy state in solvent environment. Effects of salt bridge formation on stability of α-helix structure are discussed.

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37

Jones, Christopher T., Lixin Ma, John W. Burgner, Teresa D. Groesch, Carol B. Post, and Richard J. Kuhn. "Flavivirus Capsid Is a Dimeric Alpha-Helical Protein." Journal of Virology 77, no. 12 (June 15, 2003): 7143–49. http://dx.doi.org/10.1128/jvi.77.12.7143-7149.2003.

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ABSTRACT The capsid proteins of two flaviviruses, yellow fever virus and dengue virus, were expressed in Escherichia coli and purified to near homogeneity suitable for biochemical characterization and structure determination by nuclear magnetic resonance. The oligomeric properties of the capsid protein in solution were investigated. In the absence of nucleic acid, both proteins were predominately dimeric in solution. Further analysis of both proteins with far-UV circular dichroism spectroscopy indicated that they were largely alpha-helical. The secondary structure elements of the dengue virus capsid were determined by chemical shift indexing of the sequence-specific backbone resonance assignments. The dengue virus capsid protein devoid of its C-terminal signal sequence was found to be composed of four alpha helices. The longest alpha helix, 20 residues, is located at the C terminus and has an amphipathic character. In contrast, the N terminus was found to be unstructured and could be removed without disrupting the structural integrity of the protein.

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38

de Cuevas, M., T. Tao, and L. S. Goldstein. "Evidence that the stalk of Drosophila kinesin heavy chain is an alpha-helical coiled coil." Journal of Cell Biology 116, no. 4 (February 15, 1992): 957–65. http://dx.doi.org/10.1083/jcb.116.4.957.

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Kinesin is a mechanochemical enzyme composed of three distinct domains: a globular head domain, a rodlike stalk domain, and a small globular tail domain. The stalk domain has sequence features characteristic of alpha-helical coiled coils. To gain insight into the structure of the kinesin stalk, we expressed it from a segment of the Drosophila melanogaster kinesin heavy chain gene and purified it from Escherichia coli. When observed by EM, this protein formed a rodlike structure 40-55 nm long that was occasionally bent at a hingelike region near the middle of the molecule. An additional EM study and a chemical cross-linking study showed that this protein forms a parallel dimer and that the two chains are in register. Finally, using circular dichroism spectroscopy, we showed that this protein is approximately 55-60% alpha-helical in physiological aqueous solution at 25 degrees C, and approximately 85-90% alpha-helical at 4 degrees C. From these results, we conclude that the stalk of kinesin heavy chain forms an alpha-helical coiled coil structure. The temperature dependence of the circular dichroism signal has two major transitions, at 25-30 degrees C and at 45-50 degrees C, which suggests that a portion of the alpha-helical structure in the stalk is less stable than the rest. By producing the amino-terminal (coil 1) and carboxy-terminal (coil 2) halves of the stalk separately in E. coli, we showed that the region that melts below 30 degrees C lies within coil 1, while the majority of coil 2 melts above 45 degrees C. We suggest that this difference in stability may play a role in the force-generating mechanism or regulation of kinesin.

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39

Koenis, Mark A. J., Valentin P. Nicu, Lucas Visscher, Christian Kuehn, Matthias Bremer, Mireille Krier, Harald Untenecker, Ulmas Zhumaev, Bernd Küstner, and Wybren Jan Buma. "Vibrational circular dichroism studies of exceptionally strong chirality inducers in liquid crystals." Physical Chemistry Chemical Physics 23, no. 16 (2021): 10021–28. http://dx.doi.org/10.1039/d1cp00854d.

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Chiral dopants are used in liquid crystal displays to introduce uniform helical alignment. VCD can provide unambiguous determination of the absolute configuration and structural details of such a dopant, while X-ray crystallography fails.

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40

Rabenold, David A. "Approximations for the electric dipole circular dichroism of long helical polymers." Journal of Physical Chemistry 92, no. 21 (October 1988): 5891–95. http://dx.doi.org/10.1021/j100332a010.

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41

Bloemendal, Michael, Arazdordi Toumadje, and W. Curtis Johnson. "Bovine lens crystallins do contain helical structure: a circular dichroism study." Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology 1432, no. 2 (July 1999): 234–38. http://dx.doi.org/10.1016/s0167-4838(99)00107-7.

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42

Miyahara, Tomoo, Hiroshi Nakatsuji, and Hiroshi Sugiyama. "Helical Structure and Circular Dichroism Spectra of DNA: A Theoretical Study." Journal of Physical Chemistry A 117, no. 1 (December 31, 2012): 42–55. http://dx.doi.org/10.1021/jp3085556.

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43

Fan, Zhiyuan, and Alexander O. Govorov. "Helical Metal Nanoparticle Assemblies with Defects: Plasmonic Chirality and Circular Dichroism." Journal of Physical Chemistry C 115, no. 27 (June 16, 2011): 13254–61. http://dx.doi.org/10.1021/jp204265x.

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Lalov, I. J., D. A. Svetogorski, and N. P. Turkedjiev. "Overtone spectra of helical polymers: Infrared absorption and vibrational circular dichroism." Journal of Chemical Physics 84, no. 6 (March 15, 1986): 3545–52. http://dx.doi.org/10.1063/1.450240.

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Bhattacharjee, Samita, Gergely Tóth, Sándor Lovas, and Jonathan D. Hirst. "Influence of Tyrosine on the Electronic Circular Dichroism of Helical Peptides." Journal of Physical Chemistry B 107, no. 33 (August 2003): 8682–88. http://dx.doi.org/10.1021/jp034517j.

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Kaminský, Jakub, Jan Kubelka, and Petr Bouř. "Theoretical Modeling of Peptide α-Helical Circular Dichroism in Aqueous Solution." Journal of Physical Chemistry A 115, no. 9 (March 10, 2011): 1734–42. http://dx.doi.org/10.1021/jp110418w.

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Lewis, Frederick D., Ligang Zhang, Xiaoyang Liu, Xiaobing Zuo, David M. Tiede, Hai Long, and George C. Schatz. "DNA as Helical Ruler: Exciton-Coupled Circular Dichroism in DNA Conjugates." Journal of the American Chemical Society 127, no. 41 (October 2005): 14445–53. http://dx.doi.org/10.1021/ja0539387.

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Doig, Andrew J., Charles D. Andrew, Duncan A. E. Cochran, Eleri Hughes, Simon Penel, Jia Ke Sun, Benjamin J. Stapley, David T. Clarke, and Gareth R. Jones. "Structure, stability and folding of the α-helix." Biochemical Society Symposia 68 (August 1, 2001): 95–110. http://dx.doi.org/10.1042/bss0680095.

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Abstract:

Pauling first described the α-helix nearly 50 years ago, yet new features of its structure continue to be discovered, using peptide model systems, site-directed mutagenesis, advances in theory, the expansion of the Protein Data Bank and new experimental techniques. Helical peptides in solution form a vast number of structures, including fully helical, fully coiled and partly helical. To interpret peptide results quantitatively it is essential to use a helix/coil model that includes the stabilities of all these conformations. Our models now include terms for helix interiors, capping, side-chain interactions, N-termini and 310-helices. The first three amino acids in a helix (N1, N2 and N3) and the preceding N-cap are unique, as their amide NH groups do not participate in backbone hydrogen bonding. We surveyed their structures in proteins and measured their amino acid preferences. The results are predominantly rationalized by hydrogen bonding to the free NH groups. Stabilizing side-chain-side-chain energies, including hydrophobic interactions, hydrogen bonding and polar/non-polar interactions, were measured accurately in helical peptides. Helices in proteins show a preference for having approximately an integral number of turns so that their N- and C-caps lie on the same side. There are also strong periodic trends in the likelihood of terminating a helix with a Schellman or αL C-cap motif. The kinetics of α-helix folding have been studied with stopped-flow deep ultraviolet circular dichroism using synchrotron radiation as the light source; this gives a far superior signal-to-noise ratio than a conventional instrument. We find that poly(Glu), poly(Lys) and alanine-based peptides fold in milliseconds, with longer peptides showing a transient overshoot in helix content.

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Harada, Tomoyuki, Hiroshi Yanagita, Naoya Ryu, Yutaka Okazaki, Yutaka Kuwahara, Makoto Takafuji, Shoji Nagaoka, Hirotaka Ihara, and Reiko Oda. "Lanthanide ion-doped silica nanohelix: a helical inorganic network acts as a chiral source for metal ions." Chemical Communications 57, no. 36 (2021): 4392–95. http://dx.doi.org/10.1039/d1cc01112j.

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Chiroptical properties (circular dichroism and circularly polarized luminescence) were induced in lanthanide ions by doping in silica nanohelices with a chirally arranged siloxane network without any organic mediates.

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Chai, Hanbo, William E. Allen, and Rickey P. Hicks. "Synthetic Antimicrobial Peptides Exhibit Two Different Binding Mechanisms to the Lipopolysaccharides Isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae." International Journal of Medicinal Chemistry 2014 (December 28, 2014): 1–13. http://dx.doi.org/10.1155/2014/809283.

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Circular dichroism and 1H NMR were used to investigate the interactions of a series of synthetic antimicrobial peptides (AMPs) with lipopolysaccharides (LPS) isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae. Previous CD studies with AMPs containing only three Tic-Oic dipeptide units do not exhibit helical characteristics upon interacting with small unilamellar vesicles (SUVs) consisting of LPS. Increasing the number of Tic-Oic dipeptide units to six resulted in five analogues with CD spectra that exhibited helical characteristics on binding to LPS SUVs. Spectroscopic and in vitro inhibitory data suggest that there are two possible helical conformations resulting from two different AMP-LPS binding mechanisms. Mechanism one involves a helical binding conformation where the AMP binds LPS very strongly and is not efficiently transported across the LPS bilayer resulting in the loss of inhibitory activity. Mechanism two involves a helical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity. Mechanism three involves a nonhelical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity.

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