Isolation and characterization of type III collagen from bovine cardiac muscle

Abstract

1. 1. Bovine cardiac muscle collagen was solubilized by limited digestion with pepsin and subsequently fractionated by differential salt precipitation. 2. 2. Chromatographie studies on CM-cellulose and agarose of pepsin-soluble collagen and its salt-precipitated fractions showed it to be composed of type I collagen and a species with a mol. wt of 285,000 daltons, having an amino acid composition characteristic of type III collagen. 3. 3. The molecular structure of the 285,000-dalton component was confirmed as [α1(III)] 3 after reduction with dithiothreitol to a chains having the same amino acid composition. 4. 4. Cyanogen bromide peptides of pepsin-soluble collagen which co-eluted on CM-cellulose and were identified as α1(I)-CB8 and α1(III)-CB8 showed a molar ratio of 2:1 indicating that 25% of the collagen molecules solubilized are [α1(III)] 3.