Guidon P T, Perrin D, Harrison P
Department of Biology, Seton Hall University, South Orange, New Jersey 07079, USA.
J Cell Physiol. 1996 Feb;166(2):407-12. doi: 10.1002/(SICI)1097-4652(199602)166:2<407::AID-JCP19>3.0.CO;2-7.
We have identified proteolytic activities in the rat osteoblastic osteosarcoma cell line ROS 17/2.8 which are capable of cleaving a peptide substrate for protein kinase C-mediated phosphorylation (PSPKC, Pro-Leu-Ser-Arg-Thr-Leu-Ser-Val-Ala-Ala-Lys). Using polyacrylamide gel electrophoresis conditions similar to those used to resolve small molecular weight proteins, the peptide bonds of PSPKC which are cleaved by the proteolytic activities present in ROS 17/2.8 cell lysates have been determined. These activities cleave the Ser-Arg, Thr-Leu, and Ser-Val peptide bonds. To date, no proteolytic activities present in osteoblast cell lysates have been described with the aforementioned peptide bond specificities, suggesting that these activities are novel. The PSPKC-cleaved peptide fragment pattern generated was similar for several different osteoblast cell lysates. Lysates generated from different rat tissues were also able to cleave PSPKC, but the peptide fragment pattern generated by ROS 17/2.8 cell lysates appeared to be unique amongst these tissues.
我们已在大鼠成骨细胞骨肉瘤细胞系ROS 17/2.8中鉴定出蛋白水解活性，该活性能够切割用于蛋白激酶C介导的磷酸化的肽底物（PSPKC，脯氨酸-亮氨酸-丝氨酸-精氨酸-苏氨酸-亮氨酸-丝氨酸-缬氨酸-丙氨酸-丙氨酸-赖氨酸）。使用与用于分离小分子量蛋白质相似的聚丙烯酰胺凝胶电泳条件，已确定ROS 17/2.8细胞裂解物中存在的蛋白水解活性所切割的PSPKC的肽键。这些活性切割丝氨酸-精氨酸、苏氨酸-亮氨酸和丝氨酸-缬氨酸肽键。迄今为止，尚未有文献报道成骨细胞裂解物中存在具有上述肽键特异性的蛋白水解活性，这表明这些活性是新发现的。几种不同的成骨细胞裂解物产生的PSPKC切割肽片段模式相似。来自不同大鼠组织的裂解物也能够切割PSPKC，但ROS 17/2.8细胞裂解物产生的肽片段模式在这些组织中似乎是独特的。
