Welsh C, Gay S, Rhodes R K, Pfister R, Miller E J
Biochim Biophys Acta. 1980 Sep 23;625(1):78-88. doi: 10.1016/0005-2795(80)90110-5.
Limited proteolysis of preparations of mature rabbit cornea with pepsin allows the recovery of approximately 90% of the tissue collagen in soluble form. Using recently described selective precipitation techniques, the soluble cornea collagen can be resolved into two major fractions. The predominant fraction, which accounts for about 95% of the solubilized collagen, was identified by means of solubility properties, electrophoretic and chromatographic properties, as well as amino acid analyses of its constituent chains, as Type I collagen. The alternate fraction, which accounts for virtually all of the remainder of the solubilized cornea collagen, was identified by means of the same criteria as collagen comprised of the A and B chains. In addition, the stoichiometry of the latter chains in preparations of cornea collagen indicate that in the cornea these chains are likely to participate in the formation of only one type of collagen molecule with the chain composition, AB2. And finally, the demonstration that Type I and the AB2 collagens are the predominant forms of collagen recoverable from the mature cornea strongly suggests that molecules comprised of the A and B chains are not necessarily confined to basement membrane structures.
用胃蛋白酶对成熟兔角膜制剂进行有限度的蛋白水解，可回收约90%呈可溶形式的组织胶原蛋白。利用最近描述的选择性沉淀技术，可将可溶性角膜胶原蛋白分解为两个主要部分。通过溶解性、电泳和色谱特性以及对其组成链的氨基酸分析，占溶解胶原蛋白约95%的主要部分被鉴定为I型胶原蛋白。另一部分几乎占溶解角膜胶原蛋白其余部分的全部，通过与由A链和B链组成的胶原蛋白相同的标准进行鉴定。此外，角膜胶原蛋白制剂中后一种链的化学计量表明，在角膜中这些链可能仅参与形成一种链组成为AB2的胶原蛋白分子。最后，从成熟角膜中可回收的I型和AB2型胶原蛋白是主要胶原蛋白形式这一证明，有力地表明由A链和B链组成的分子不一定局限于基底膜结构。
