Carbohydrate Polymers 2 ( 1982) 171 - 191 CONFIGURATIONAL STATISTICS OF SINGLE CHAINS OF o~-LINKED GLUCANS DIDIER GAGNAIRE, SERGE PI~REZ~t Centre de Recherches sur les Macromoldcules Vdgdtales (CNRS/*, 53X, 38041 Grenoble Cddex, France & VINH TRAN~" Laboratoires de Chimie, Groupe Macromoldcules Vdgdtales, Ddpartement de Recherche Fondamentale, Centre d'Etudes Nucldaires, 85X, 38041 Grenoble Cddex, France (Received: 23 March, 1982) ABSTRACT Unperturbed chain conformations are evaluated assuming separable chain configura- tion energies. Spatial chain propagations are constructed assuming an equiprobable occurrence of conformational states within topographically selected portions of the allowed energy space. Random coil dimensions, along with spatial representations of some single chains of t~-linked glucans, such as amylose, pseudo-nigerose, nigeran and linear dextran are reported. Significant architectural differences are observed for these different t~-linked glucan chains, since disordered random-coil as well as persistent pseudo-helical character, either cyclic or linear, are found, depending on the type of glycosidic linkage. l. INTRODUCTION Polysaccharides offer an almost unlimited range of possible structures. To understand their properties it is not only necessary to elucidate their chemical structure but also to characterise their conformations and complete three-dimensional structures. The use of accurate molecular descriptions, as drawn from the crystallographic studies on * Laboratoire Propre du CNRS, associ6 h l'Universit6 Scientifique et M6dicale de Grenoble. t Present address: Laboratoire de Stockage et de Conservation des Denrbes Alimentaires, INRA, Centre de Recherches de Nantes, Chemin de la G6raudi~re, 44072 Nantes C6dex, France. To whom all correspondence should be addressed. 171 Carbohydrate Polymers 0144-8617/82/0002-0171/$02.75 © Applied Science Publishers Lid, England, 1982 Printed in Great Britain