Collagen-platelet interaction. Type V (A-B) collagen induced platelet aggregation
Chiang, T.M.; Mainardi, C.L.; Seyer, J.M.; Kang, A.H.
Journal of Laboratory and Clinical Medicine 95(1): 99-107
1980
ISSN/ISBN: 0022-2143 PMID: 7350245 Document Number: 158136
One of the more recently discovered collagens, type V (or A-B) collagen, in its native fibrillar form mediates human platelet aggregation and the release of serotonin. In agreement with a recent report, it had no detectable effect on human platelets in the soluble or amorphous form. That the observed results might be due to contaminating interstitial collagens was eliminated by taking advantage of unusual solubility properties of type V collagen. Type V collagen dissolved in 0.1 M acetic acid formed native-type fibrils when dialyzed against PBS [phosphate-buffered solution] and amorphous fibrils when dialyzed against 0.05 M Tris/0.13 M NaCl, pH 7.4, at 4.degree. C. Interstitial collagens remained in solution under these conditions. Type V collagen treated with sufficient, purified synovial collagenase to digest all contaminating interstitial collagen retained its platelet-aggregating properties. Purity of type V collagen was confirmed by SDS-PAGE [sodium dodecyl sulfate-polyacrylamide gel electrophoresis] of CNBr digests. The quaternary structure of type V collagen apparently is important in its recognition by platelet membranes.