Enkephalin analogs. Introduction of stereochemical constraints, metal binding sites and fluorescent groups

Nagaraj, R. ; Sudha, T. S. ; Shivaji, S. ; Balaram, P. (1979) Enkephalin analogs. Introduction of stereochemical constraints, metal binding sites and fluorescent groups FEBS Letters, 106 (2). pp. 271-274. ISSN 0014-5793

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Official URL: http://dx.doi.org/10.1016/0014-5793(79)80512-8

Related URL: http://dx.doi.org/10.1016/0014-5793(79)80512-8

Abstract

There has been considerable speculation on the biologically active conformations of the enkephalins and their possible structural similarity to the opiates [1- 4]. A number of models have been proposed on the basis of theoretical calculations [2] and computer modelling [3]. Recent NMR studies suggest a high degree of conformational flexibility at Gly2 and Gly3 implying that a favoured conformation does not exist in aqueous solution [5]. The replacement of the Gly residues by Aib residues will greatly restrict the available conformations at positions 2 and 3 of the pentapeptides and may thereby allow a better definition of the steric requirements for biological activity. This approach appears particularly attractive in view of the extremely well defined conformations adopted by Aib containing peptides [6 -10]. An earlier report described the synthesis of Aib2 - Met3 -enkephalin-amide [11]. Here we present the preparation and compare the biological properties of the Aib2, Aib3, and Aib2 - Aib3 Met5 -enkephalin derivatives. The properties of 3-nitro-Tyr analogs, designed to bind paramagnetic NMR shift probes and a fluorescent Aib2 analog developed for studies of receptor interactions, are also described.

Item Type:Article
Source:Copyright of this article belongs to Federation of European Biochemical Societies.
ID Code:23505
Deposited On:25 Nov 2010 13:13
Last Modified:17 May 2016 07:19

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