DELAYED TRIPLE-HELIX FORMATION OF MUTANT COLLAGEN FROM PATIENTS WITH OSTEOGENESIS IMPERFECTA
DELAYED TRIPLE-HELIX FORMATION OF MUTANT COLLAGEN FROM PATIENTS WITH OSTEOGENESIS IMPERFECTA
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DOI：
10.1006/jmbi.1994.1199
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发表时间：
1994-02-25
影响因子：
5.6
通讯作者：
STEINMANN, B
中科院分区：
文献类型：
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作者：
RAGHUNATH, M;BRUCKNER, P;STEINMANN, B
在6例遗传性结缔组织疾病成骨不全症（OI）患者的正常人成纤维细胞培养物和细胞株中测量了I型前胶原蛋白三螺旋形成的动力学。在用[35S]蛋氨酸进行4分钟脉冲标记后，对蛋白酶抗性和螺旋型胶原分子的出现进行可变追踪时间的跟踪。在对照细胞中，50%的分子在14分钟后完全呈三螺旋状。在α1(I)-链螺旋结构域的94、223、526、691和988位含有单一Gly→Cys取代的6株OI细胞株中，包含两个突变α1(I)-链的全长蛋白酶抗性分子的形成（通过二硫连接α1(I)-二聚体的外观来判断）延迟了5至60分钟。该延迟与含有α1(I)-二聚体的异常胶原分子的热稳定性呈负相关。第6株c端三螺旋区外1017位Gly→Cys取代的细胞株的I型前胶原折叠时间和熔化温度正常。在这里，我们证明了迄今为止假设的α1(I)链中含有Gly→Cys取代的胶原蛋白分子的拉链状折叠延迟影响分子的螺旋部分。
The kinetics of triple helix formation of procollagen I were measured in normal human fibroblast cultures and cell strains from six patients with osteogenesis imperfecta (OI), a heritable connective tissue disorder. After a 4-minute pulse-labelling with [35S]methionine, the appearance of protease-resistant and thus helical collagen molecules was followed for variable chase times. In control cells, 50% of the molecules were fully triple-helical after 14 minutes. In the six OI cell strains harbouring a single Gly→Cys substitution at positions 94, 223, 526, 691 and 988 in the helical domain of the α1(I)-chain, formation of full-length protease-resistant molecules containing two mutant α1(I)-chains as judged by the appearance of disulphide-linked α1(I)-dimers was delayed by 5 to 60 minutes. The delay inversely correlated with the thermal stability of abnormal collagen molecules containing α1(I)-dimers. Folding time and melting temperature of procollagen I in the sixth cell strain with a Gly→Cys substitution at position 1017, outside the triple helical region in the C-terminal telopeptide, were normal. Here, we demonstrate the hitherto postulated delay in the zipper-like folding of collagen molecules harbouring Gly→Cys substitutions in the α1(I)-chain affecting the helical part of the molecule.