Conformational aspects of polypeptides. XI. The nitroaromatic effect

Goodman, Murray; Félix, Arthur; Deber, Charles M.; Brause, Allan R.; Schwartz, Gerald

doi:10.1002/bip.360010409

Cited by 96 publications

(22 citation statements)

References 23 publications

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“…In this connection, a few publications have recently reported very stimulating results on the preferred helical handedness of homo‐oligopeptides based on C α ‐ tetra substituted α‐amino acids with only side‐chain chirality 63–66. As far as the large field of helical oligo‐ and polypeptides formed by C α ‐ tri substituted α‐amino acids is concerned, only a limited number of scattered data is available,3–5, 7–10, 67–78 which does not allow one to extract a general picture of this important 3D‐structural issue.…”

Section: Resultsmentioning

confidence: 99%

Handedness control of peptide helices by amino acid side‐chain chirality: Ile/aIle peptides

et al. 2006

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A set of four hexapeptide sequences, each characterized by four strongly helicogenic Aib residues and all combinations of two isomeric Ile/aIle residues at positions 2 and 5, was synthesized by solution methods and fully characterized. A detailed solution (by FT-IR absorption, NMR, and CD techniques) and solid/crystalline state (by X-ray diffraction) conformational investigation allowed us to validate our assumption that all four peptides are folded in well-developed 3(10)-helical structures. However, the most relevant conformational conclusion extracted from the present 3D-analysis is that the handedness of the 3(10)-helical structures formed does not seem to be sensitive to the configurational change at the beta-carbon atom of the constituent Ile versus the diastereomeric aIle residues (in other words, the dominant control on this important structural parameter appears to be exerted by the chirality of the amino acid alpha-carbon atom). These results complement published findings on the diverging relative stabilities of the intermolecularly H-bonded beta-sheet structures generated by Ile versus aIle homo-oligopeptides.

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Section: Resultsmentioning

confidence: 99%

Handedness control of peptide helices by amino acid side‐chain chirality: Ile/aIle peptides

et al. 2006

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“…PClBLA studied in this work also follows this pattern 42, 43. The helix‐sense inversion of copolymers studied by Goodman and his group1, 2, 6–8, 16, 17 in earlier years seems to involve the same transition mechanism 44…”

Section: Discussionmentioning

confidence: 82%

“…Poly(β‐benzyl L ‐aspartate) (PBLA) takes the left form and does not exhibit any screw‐sense inversion. Reversal of the helix sense in copolymer systems such as those comprising X 1 = nitrobenzyl and X 2 = benzyl residues has been extensively investigated by Goodman and his coworkers1, 2 as early as in 1960s. An extensive investigation by Hashimoto et al3–5 revealed that the screw‐sense reversal takes place sensitively with the chemical nature of the surrounding media.…”

Section: Introductionmentioning

confidence: 99%

Three‐dimensional EPR/NMR image coregistration using a MATLAB‐based software

Ohfuchi

Goodwin

Fujii

et al. 2011

Concepts Magn Reson

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ABSTRACT:The coregistration of electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) images in three-dimensional (3D) data space typically involves a process of visual inspection and manual alignment of the images. This is due primarily to the use of separate scanners, which can result in a number of potential differences between the two image types, such as resolution, field-of-view, and image orientation. In this article, we describe recently developed methodology and software that enables automatic coregistration of EPR and NMR acquired images without the need for manual alignment. The technique requires the use of fiducial markers during both EPR and NMR image acquisition, which contain a solution of free radical spin probes, and allow adjustment of the positions and the fields-of-view of the measured images. In this work we present results for EPR/NMR image coregistration using an isoflurane-anesthetized mouse, injected with triarylmethyl radical (Oxo63) spin probes. The same spin probes were also used inside the fiducial markers and in plastic tubes used for phantom measurements. Using our MATLAB-based software, we were able to successfully coregister EPR/NMR images in approximately 60 s.

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“…It is well known that polyaspartates form right‐ or left‐handed helices depending on the side chain structure, solvent, and temperature . While poly(β‐benzyl‐L‐aspartate) (PBLA) forms a left‐handed α‐helix (αL‐helix) in chloroform, polyaspartates bearing para ‐substituted benzyl groups, long n ‐alkyl groups, phenethyl moieties, etc, form a right‐handed α‐helices (αR‐helices) .…”

Section: Introductionmentioning

confidence: 99%

Insights into the helix‐sense inversion of poly(β‐phenethyl‐L‐aspartate) by two‐dimensional Raman correlation spectroscopy

Suzuki

Furuya

2018

Journal of Peptide Science

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In this study, the transition process of the helix-sense inversion of poly(β-phenethyl-L-aspartate) was investigated by Raman scattering and 2-dimensional correlation spectroscopy. Temperature-dependent Raman spectra were obtained during the helix-sense inversion. The results of 2-dimensional correlation analysis in the spectral regions of 1600-1800 and 3200-3400 cm showed that the intensity changes of the side-chain ester C═O stretching bands occurred prior to those of amide A and amide I bands in the unwinding process of αR-helix on heating. The sequential order of the intensity changes for amide A, amide I, and the side-chain ester C═O stretching bands during the inversion process was determined. It was found that the conformation change of the side chain occurred prior to that of the main chain for the αR-helix on heating. Thus, we concluded that the transformation of the backbone chain from right-handed to left-handed is triggered by the conformational change of the side chains.

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Conformational aspects of polypeptides. XI. The nitroaromatic effect

Cited by 96 publications

References 23 publications

Handedness control of peptide helices by amino acid side‐chain chirality: Ile/aIle peptides

Handedness control of peptide helices by amino acid side‐chain chirality: Ile/aIle peptides

Three‐dimensional EPR/NMR image coregistration using a MATLAB‐based software

Insights into the helix‐sense inversion of poly(β‐phenethyl‐L‐aspartate) by two‐dimensional Raman correlation spectroscopy

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