Molecular structure of Boc-Aib-Aib-Phe-Met-NH2·DMSO. A fragment of a biologically active enkephalin analogue

Prasad, B. V. Venkataram ; Sudha, T. Subrahmanyam ; Balaram, Padmanabhan (1983) Molecular structure of Boc-Aib-Aib-Phe-Met-NH2·DMSO. A fragment of a biologically active enkephalin analogue Journal of Chemical Soceity, Perkin Transanction 1 . pp. 417-421. ISSN 0300-922X

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Official URL: http://www.rsc.org/Publishing/Journals/P1/article....

Related URL: http://dx.doi.org/10.1039/P19830000417

Abstract

The tetrapeptide t-butyloxycarbonyl-α-aminoisobutyryl-α-aminoisobutyryl-L- phenylalanyl-L-methionyl amide crystallizes in the orthorhombic space group P212121 with a= 9.096, b= 18.067, c= 21.701 Å and Z= 4. The crystals contain one molecule of dimethyl sulphoxide (DMSO) associated with each peptide. The structure has been solved by direct methods and refined to an R value of 0.103 for 2 672 observed reflections. The peptide adopts a distorted 310 helical structure stabilized by two intramolecular 4 → 1 hydrogen bonds between the Boc CO and Aib(1) CO groups and the NH groups of Phe(3) and Met(4), respectively. A long hydrogen bond (N...O = 3.35 Å) is also observed between Aib(2) CO and one of the terminal amide hydrogens. The DMSO molecule is strongly hydrogen bonded to the Aib(1) NH group. The solid-state conformation agrees well with proposals made on the basis of n.m.r. studies in solution.

Item Type:Article
Source:Copyright of this article belongs to Royal Society of Chemistry.
ID Code:4920
Deposited On:18 Oct 2010 06:14
Last Modified:16 May 2016 15:30

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