Studies on a distinct fraction of bovine vitreous body collagen.

We were able to separate pepsin-solubilized collagen of the bovine vitreous body into three distinct fractions by differential salt precipitation with 0.5 M acetic acid containing 0.7 M, 1.2 M, and 2.0 M NaCl, respectively. The 0.7 M NaCl fraction showed an electrophoretic mobility in polyacrylamide gel identical to that of type II collagen, CNBr-derived peptides very similar to type II collagen CNBr-peptides, and a reaggregation behaviour closely related to type II collagen as observed by electron microscopy. Therefore, the fibres of the bovine vitreous body appear to contain a mixture of a collagen very similar to type II collagen precipitable in the presence of 0.7 M NaCl, at least two different collagen types that can be precipitated at 1.2 M, and 2.0 M NaCl concentrations that have not been identified previously.