Kuo H J, Keene D R, Glanville R W
Shriners Hospital for Crippled Children, Portland, Oregon 97201.
Biochemistry. 1989 May 2;28(9):3757-62. doi: 10.1021/bi00435a020.
Type VI collagen, prepared from guanidine extracts of human amnion, contains very little monomeric material, the major forms being dimers and tetramers. In order to study the orientation of the molecules in these aggregates, they were digested with pepsin followed by bacterial collagenase. Two fragments were isolated, one containing part of the inner globular domain still attached to part of the triple helix and the other containing large fragments of the outer globular domain. Each fraction was further analyzed; peptides were isolated and their amino-terminal amino acid sequences determined. By comparing the determined sequences with published data, it was found that the outer globular domain contained sequences derived from the amino-terminal domain of all three chains of type VI collagen whereas the inner globular domain contained sequences from the carboxy-terminal domain. This provided direct chemical evidence that dimers and tetramers of type VI collagen are formed by overlapping carboxy-terminal regions of the monomers.
从人羊膜的胍提取物中制备的VI型胶原蛋白几乎不包含单体物质，主要形式是二聚体和四聚体。为了研究这些聚集体中分子的取向，先用胃蛋白酶消化它们，然后用细菌胶原酶处理。分离出两个片段，一个包含仍与部分三螺旋相连的内部球状结构域的一部分，另一个包含外部球状结构域的大片段。对每个组分进行进一步分析；分离出肽并确定其氨基末端氨基酸序列。通过将确定的序列与已发表的数据进行比较，发现外部球状结构域包含源自VI型胶原蛋白所有三条链的氨基末端结构域的序列，而内部球状结构域包含来自羧基末端结构域的序列。这提供了直接的化学证据，表明VI型胶原蛋白的二聚体和四聚体是由单体的羧基末端区域重叠形成的。
