Structures of the amylopectins of waxy, normal, amylose-extender, and wx:ae genotypes and of the phytoglycogen of maize

Carbohydr Res. 1993 May 7;243(2):307-21. doi: 10.1016/0008-6215(93)87035-q.

Abstract

Average chain lengths and beta-amylolysis limits have been determined for the waxy and ae/wx genotypes of mature maize starch, and for the amylopectin fractions of normal and amylose-extender starches (prepared by precipitation with concanavalin A), rabbit-liver glycogen, phytoglycogen, and waxy rice starch. All amylopectin samples had similar A:B chain ratios of > 1 and the two glycogens had ratios of < 1. This finding led to average frequencies of substitution of B chains over the whole molecule of > 2 for the amylopectins and < 2 for the glycogens. An equation for the number of tiers for a molecule with various frequencies of substitution of B chains and chain lengths has been used to determine the effect of variation in average frequency of branching and average chain length on structure.

Publication types

  • Comparative Study

MeSH terms

  • Amylopectin / chemistry*
  • Amylopectin / isolation & purification
  • Animals
  • Carbohydrate Sequence
  • Genotype
  • Glycogen / chemistry*
  • Glycogen / genetics
  • Liver Glycogen / chemistry*
  • Mathematics
  • Models, Biological
  • Molecular Sequence Data
  • Oligosaccharides / chemistry
  • Oligosaccharides / isolation & purification
  • Rabbits
  • Zea mays / chemistry
  • Zea mays / genetics*

Substances

  • Liver Glycogen
  • Oligosaccharides
  • Glycogen
  • Amylopectin