CELL-LAYER-ASSOCIATED PROTEOLYTIC CLEAVAGE OF THE TELOPEPTIDES OF TYPE-I COLLAGEN IN FIBROBLAST-CULTURE
CELL-LAYER-ASSOCIATED PROTEOLYTIC CLEAVAGE OF THE TELOPEPTIDES OF TYPE-I COLLAGEN IN FIBROBLAST-CULTURE
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DOI：
10.1042/bj2450677
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发表时间：
1987-08-01
影响因子：
4.1
通讯作者：
COLE, WG
中科院分区：
文献类型：
--
作者：
BATEMAN, JF;PILLOW, JJ;COLE, WG
在人皮肤成纤维细胞培养中，一部分被加工成胶原并留在细胞层的前胶原通过去除N-末端和C-末端端肽进一步进行蛋白水解性修饰。蛋白分解活性与细胞层有关，因为分泌的胶原蛋白总是含有完整的端肽。中性聚合物的夹杂，导致细胞层中胶原的积累[贝特曼，科尔，Pillow和Ramshaw(1986)J.Biol]。化学。261,4198-4203]，使端肽在表达蛋白分解活性的细胞中的裂解更加明显。这种分裂的程度在不同的细胞培养和同一成纤维细胞系的不同实验之间是不同的。蛋白水解酶的活性依赖于pH，当培养基pH为7.5和8.0时，裂解活性最大，当培养基pH为7.0和6.5时，裂解完全被抑制。大豆胰蛋白酶抑制剂、弹性酶特异性抑制剂(N-acetylalanylalanylprolylvalylchloromethane)和凝血酶抑制剂水飞蓟素显著抑制该酶的活性。这种细胞相关的蛋白分解活性可能通过去除作为胶原交联的主要部位的端肽而在胶原降解中发挥作用，从而充分破坏胶原基质的稳定性，使其容易进一步的蛋白分解。
In human skin fibroblast cultures a fraction of the procollagen that was processed to collagen and remained in the cell layer was further proteolytically modified by removal of both N- and C-terminal telopeptides. The proteolytic activity was associated with the cell layer, since secreted collagens were found always to contain intact telopeptides. The inclusion of neutral polymers, which caused the accumulation of the collagen in the cell layer [Bateman, Cole, Pillow and Ramshaw (1986) J. Biol. Chem. 261, 4198-4203], made the telopeptide cleavage more apparent in those cells which expressed the proteolytic activity. The extent of this cleavage was variable from cell culture to cell culture and between experiments with the same fibroblast line. The proteolytic activity was pH-dependent; cleavage was greatest at a culture-medium pH of 7.5 and 8.0 and was completely inhibited at a culture-medium pH of 7.0 and 6.5. The activity was significantly inhibited by soybean trypsin inhibitor, an elastase-specific inhibitor (N-acetylalanylalanylprolylvalylchloromethane) and the thrombin inhibitor hirudin. This cell-associated proteolytic activity may play a role in collagen degradation by removing the telopeptides, which are the primary sites of collagen cross-linking, thus destabilizing the collagen matrix sufficiently to render it susceptible to further proteolytic breakdown.