Morton L F, Young R D, Barnes M J
Coll Relat Res. 1985 Dec;5(6):493-503. doi: 10.1016/s0174-173x(85)80003-0.
Collagen type VI in native (undenatured or triple-helical) form has been shown, like collagen types I-V, alpha 1(I) trimer and alpha 2(I) trimer, to possess platelet reactivity provided that essential quaternary structural needs are first satisfied. Thus platelet aggregation was induced by the collagenous domain of collagen type VI, isolated free of the non-collagenous elements, when this entity was presented to platelets in fibrillar form. This implies that platelet recognition sites in collagen type VI are located in the collagenous sequence of the molecule. Aggregation of platelets was also induced, although a higher concentration was required, by the intact, "parent" collagen following its polymerisation by random association of molecules with the aid of a cross-linking agent (glutaraldehyde) to yield an amorphous polymer. This permits the suggestion that the more ordered molecular assembly of collagen type VI thought to occur in vivo, to yield a microfibrillar form, is likely to be associated with significant platelet reactivity. Our results support the notion that any collagenous species may be reactive towards platelets provided that essential tertiary and quaternary structural requirements are met and in this sense, therefore, they favour more the idea of multiple platelet-reactive sites in collagen of relatively low structural specificity and low affinity.
已表明，天然（未变性或三螺旋）形式的VI型胶原蛋白与I-V型胶原蛋白、α1(I)三聚体和α2(I)三聚体一样，只要首先满足基本的四级结构需求，就具有血小板反应性。因此，当以纤维状形式将不含非胶原蛋白成分的VI型胶原蛋白的胶原结构域呈现给血小板时，会诱导血小板聚集。这意味着VI型胶原蛋白中的血小板识别位点位于分子的胶原序列中。通过分子借助交联剂（戊二醛）随机缔合使其聚合以产生无定形聚合物后的完整“母体”胶原蛋白，也能诱导血小板聚集，尽管需要更高的浓度。这表明，被认为在体内发生的VI型胶原蛋白更有序的分子组装以产生微纤维形式，可能与显著的血小板反应性相关。我们的结果支持这样一种观点，即只要满足基本的三级和四级结构要求，任何胶原物种都可能对血小板有反应，因此从这个意义上说，它们更倾向于认为胶原蛋白中存在多个具有相对低结构特异性和低亲和力的血小板反应位点的观点。
