Peptide Mapping of Cornea Collagens from Chick Embryos by Dodecylsulfate/Polyacrylamide Gel Electrophoresis

Abstract

Using differential salt fractionation, different collagen types were obtained from corneas of 17‐day‐old chick embryos. The collagen precipitated by 1.7 M and 2.5 M NaCl consisted of type I collagen, having an α1:α2 ratio of 2. The collagen precipitated by 5 M NaCl contained αA, αB, α1 and α2 chains having an αA:αB ratio of 1 and an α1:α2 ratio of 10. The α1 and α2 chains isolated from corneas were found to have higher mobility in polyacrylamide gel electrophoresis in sodium dodecylsulfate as compared with that of their counterparts isolated from embryonic chick tendons. When the α1 and α2 chains isolated by polyacrylamide gel electrophoresis in sodium dodecylsulfate were subjected to limited protease degradations, the peptide maps obtained from corneal α chains were not identical to those of tendon α chains. It is suggested that the type I collagen in cornea is different from type I collagen in tendon. Also the results indicated that the α1 chain present in the 5 M NaCl precipitate is a type I α1 chain. Copyright © 1980, Wiley Blackwell. All rights reserved