Polysaccharides

Abstract

This review will be a discussion of some of the papers on a selected num ber of topics of polysaccharide biochemistry. Reviews relevant to the topics discussed arc indicated at the appropriate places in the text.The main trends in the work on the chemistry of the polysaccharides have been toward improved methods of isolating the materials with the use of cationic detergents, ion exchange cellulose columns, and electrophoresis; the exploration of the detailed fine structure of the polysaccharides by analyses of partial acid and enzymic hydrolysates; and the use of periodate oxidation methods. While new enzymic routes for synthesis and degradation of polysac charides have been investigated, exciting new biochemical developments in the biological control and cytological location of the enzymic systems have been made.

Freezing Stresses and Survival

“…2 The structure of xylans obtained from seed and other tender tissues of the plant is known to vary, particularly in complexity and frequency of branching units from the xylose chain. Those from the least hardy species have the simplest structure (5,9,52,104,105,144,156,161,163). The types of branching units are genetically controlled.…”

Carbohydrate Metabolism

“…Glycoproteins.-As the structure of many glycoproteins has become clearer (84)(85)(86), interest in their metabolism has shifted from measuring overall kinetics of their synthesis (e.g., [87][88][89][90][91][92] to elucidating mechanisms of synthesis. In particular three questions have been raised: (a) are sugars linked to amino acids before, during or after polypeptide formation; (b) in what subcellular site is this accomplished; and (c) are the sugars added singly, as in the formation of bacterial "core" lipopolysaccharides (see below), or in blocks?…”