Chiang T M, Mainardi C L, Seyer J M, Kang A H
J Lab Clin Med. 1980 Jan;95(1):99-107.
One of the more recently discovered collagens, type V (or A-B) collagen, in its native fibillar form mediates human platelet aggregation and the release of serotonin. In agreement with a recent report, it has no detectable effect on human platelets in the soluble or amorphous form. The possibility 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 0.1M acetic acid formed native-type fibrils when dialyzed against PBS and amorphous fibrils when dislyzed against 0.05M Tris/0.13M NaCl, pH 7.4, at 4 degrees C. Interstitial collagens remained in solution under both of these conditions. In addition, type V collagen treated with sufficient, purified synovial collagenase to digest all contaminating interstitial collagen retained its platelet-aggregating properties. The purity of type V collagen was confirmed by SDS-PAGE of CNBr digests. These data indicate that the quaternary structure of type V collagen is important in its recognition by platelet membranes.
最近发现的胶原蛋白之一，V型（或A - B型）胶原蛋白，以其天然纤维形式介导人类血小板聚集和血清素释放。与最近的一份报告一致，其可溶或无定形形式对人类血小板没有可检测到的影响。利用V型胶原蛋白不同寻常的溶解性，排除了观察到的结果可能是由于污染的间质胶原蛋白所致的可能性。溶解于0.1M乙酸中的V型胶原蛋白，在对PBS进行透析时形成天然型纤维，而在4℃下对pH 7.4的0.05M Tris/0.13M NaCl进行透析时形成无定形纤维。间质胶原蛋白在这两种条件下均保留在溶液中。此外，用足够的纯化滑膜胶原酶处理以消化所有污染的间质胶原蛋白的V型胶原蛋白，仍保留其血小板聚集特性。通过对CNBr消化产物进行SDS - PAGE证实了V型胶原蛋白的纯度。这些数据表明，V型胶原蛋白的四级结构在其被血小板膜识别中很重要。
