Fernandes R J, Schmid T M, Harkey M A, Eyre D R
Department of Orthopaedics, University of Washington, Seattle 98195, USA.
Eur J Biochem. 1997 Jul 15;247(2):620-4. doi: 10.1111/j.1432-1033.1997.00620.x.
The Swarm rat chondrosarcoma cell line, RCS-LTC, deposits an extracellular matrix that contains the typical type II, IX, and XI collagen phenotype of hyaline cartilage, but the fibrils appear abnormally thin. By N-terminal sequence analysis, the type II collagen from the matrix was shown to have retained its N-propeptides with no evidence of normal processing to type II collagen. Amplification and sequencing of cDNA prepared from the pro alpha1(II) mRNA of these cells showed a normal N-propeptide cleavage site. Furthermore, the type II N-procollagen could be processed to type II collagen by incubation with culture medium from normal chondrocytes. The findings indicate that the RCS-LTC cell line fails to express an active type II procollagen N-proteinase and, therefore, offers a useful culture system in which to study the role of N-propeptide removal in fibrillogenesis.
群体大鼠软骨肉瘤细胞系RCS-LTC能分泌一种细胞外基质，该基质含有透明软骨典型的II型、IX型和XI型胶原蛋白表型，但原纤维显得异常纤细。通过N端序列分析表明，基质中的II型胶原蛋白保留了其N端前肽，没有正常加工成II型胶原蛋白的迹象。对这些细胞的原α1(II) mRNA制备的cDNA进行扩增和测序，结果显示有一个正常的N端前肽切割位点。此外，将II型前胶原蛋白与正常软骨细胞的培养基一起孵育，可将其加工成II型胶原蛋白。这些发现表明，RCS-LTC细胞系不能表达活性II型前胶原N蛋白酶，因此，它提供了一个有用的培养系统，可用于研究去除N端前肽在纤维形成中的作用。
