Non‐helical regions in rat collagen α1‐chain
Non‐helical regions in rat collagen α1‐chain
复制标题
大鼠胶原蛋白 α1 链的非螺旋区域
DOI：
10.1016/0014-5793(72)80542-8
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发表时间：
1972
期刊：
影响因子：
3.5
通讯作者：
K. Kühn
中科院分区：
文献类型：
--
作者：
M. Stoltz;R. Timpl;K. Kühn
三螺旋胶原蛋白分子在两个末端位点都含有短的非螺旋区域，这些区域对于交联很重要[1，2]并具有主要的抗原活性[3-51]。这些区域的序列研究[6，7]揭示了甘氨酸不占据每三个位置，这被认为是三螺旋组装的先决条件。虽然N-末端区域在几年前就已被表征[1，6]，但直到最近才在小牛和兔胶原蛋白中证明了C-末端对应物[8，9]。这可以通过这些特定的非螺旋序列对组织蛋白酶降解的高度敏感性来解释，这可以通过在变性条件下提取胶原蛋白O-链来防止[S，7，9]。到目前为止，还没有证据表明大鼠胶原czl链中存在C-末端非螺旋区。报道的中性盐提取的大鼠胶原蛋白[lo]的C-末端溴化氰（CNBr）肽czl-CB 6的氨基酸组成表明其不存在（参见[5，8，1 l]）。此外，对大鼠肌腱[121]和皮肤胶原[6]的N-末端区域的比较序列研究表明，后者缺少四个氨基酸残基。考虑到这些数据可能反映了提取工艺，通过最近建立的改进方法[5，8，9]重新研究了这种胶原蛋白的非螺旋区域的出现和性质问题。
The triple-helical collagen molecule contains at both terminal sites short, non-helical areas being important for cross-linking [1, 2] and bearing the major antigenic activity [3-51. Sequence studies of these regions [6, 7] have revealed that glycine does not occupy every third position which is considered a prerequisite for triple-helical assembly. Although the N-terminal regions were already characterized some years ago [1, 6], the demonstration of C-terminal counterparts in calf and rabbit collagen [8, 9] was achieved only recently. This is explained by the high susceptibility of these particular non-helical sequences to degradation by tissue proteases which can be prevented by extraction of the collagen o-chains under denaturating conditions [S, 7, 9]. As yet no evidence was available for a C-terminal, non-helical region in the rat collagen czl-chain. The amino acid composition reported for the C-terminal cyanogen bromide (CNBr) peptide czl-CB6 of neutral salt-extracted rat collagen [lo] rather suggested its absence (cf.[5, 8, 1 l]). Furthermore, comparative sequence studies on the N-terminal region of rat tendon [121 and skin collagen [6] demonstrated the lack of four amino acid residues in the latter. Considering that these data may reflect extraction artzfacts, the question on the occurrence and nature of non-hel-ical regions was reinvestigated for this kind of collagen by improved methods recently established [5, 8, 9].