Answers are grounded in this paper and cite their sources.
The two collagens of cartilage differing in primary structure, extracted from lathyritic chick xiphoid processes, can be separated from each other in their native forms by differential salt precipitation. One form, [α1(I)]2α2, present in smaller amount, is less soluble and is precipitated by 2.2 m NaCl at neutral pH; the other form, [α1(II)]3, which remains in solution, can be precipitated by dialysis at very low ionic strength. The two different α1 chains, α1(I) and α1(II) which chromatograph close to one another on CM-cellulose, can be completely separated under mildly alkaline conditions on an anion exchange resin, DEAE-cellulose, by stepwise elution with buffers of decreasing pH. This chromatographic technique for collagen chain separation has revealed microheterogeneity of both types of α1 chains by separating a number of components displaying only small differences in amino acid content, principally in the hydroxylysine moiety.
No takes yet. Share an insight, caveat, or question.
Trelstad et al. (1972) studied this question.