The side-chain hydroxy groups of a cyclic α,α-disubstituted α-amino acid promote oligopeptide 310-helix packing in the crystalline state
Autor: | Takashi Misawa, Hiroko Yamashita, Hiroshi Suemune, Yosuke Demizu, Masaaki Kurihara, Masakazu Tanaka, Makoto Oba, Mitsunobu Doi |
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Rok vydání: | 2016 |
Předmět: |
chemistry.chemical_classification
Oligopeptide Tetrapeptide 010405 organic chemistry Hydrogen bond Stereochemistry Organic Chemistry Biophysics Peptide General Medicine 010402 general chemistry 01 natural sciences Biochemistry 0104 chemical sciences Amino acid Biomaterials Residue (chemistry) chemistry 310 helix Side chain |
Zdroj: | Biopolymers. 106:757-768 |
ISSN: | 0006-3525 |
Popis: | A single chiral cyclic α,α-disubstituted amino acid with side-chain methoxymethyl (MOM) protecting groups, (3S,4S)-1-amino-(3,4-dimethoxymethoxy)cyclopentanecarboxylic acid [(S, S)-Ac5 c(dOMOM) ], or side-chain hydroxy groups, (3S,4S)-1-amino-(3,4-dihydroxy)cyclopentanecarboxylic acid [(S, S)-Ac5 c(dOH) ], was attached to the N-terminal or C-terminal position of α-aminoisobutyric acid (Aib) tetrapeptide segments; i.e., we designed and synthesized four pentapeptides, Cbz-[(S, S)-Ac5 c(dOMOM) ]-(Aib)4 -OEt (1), Cbz-[(S, S)-Ac5 c(dOH) ]-(Aib)4 -OEt (2), Cbz-(Aib)4 -[(S, S)-Ac5 c(dOMOM) ]-OMe (3), and Cbz-(Aib)4 -[(S, S)-Ac5 c(dOH) ]-OMe (4). We then analyzed the peptides' structures in the crystalline state. The four peptides all folded into 310 -helical structures; 1 formed a left-handed (M) 310 -helix, 2 formed a mixture of right-handed (P) and (M) 310 -helices, 3 formed a mixture of (P) and (M) 310 -helices, and 4 formed a (P) 310 -helix, respectively. In packing mode, the molecules of peptides 1 and 3, which both possessed an Ac5 c(dOMOM) residue, were connected by intermolecular hydrogen bonds along the peptide backbone (NH···O type). On the other hand, the packing of peptides 2 and 4, which both contained an Ac5 c(dOH) residue, was based on intermolecular hydrogen bonds derived from both the peptide backbone and the side-chain hydroxy groups of the amino acid Ac5 c(dOH) (OH···O type). © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 757-768, 2016. |
Databáze: | OpenAIRE |
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