McClelland P, Hathaway D R
Department of Medicine, Indiana University School of Medicine, Indianapolis 46202.
FEBS Lett. 1991 Sep 23;290(1-2):55-7. doi: 10.1016/0014-5793(91)81224-v.
Vascular smooth muscle contains large amounts of the Ca(2+)-dependent protease calpain II. In this study, we compared bovine aortic muscle (muscle phenotype) to cultured bovine aortic cells of smooth muscle origin (modulated phenotype) with respect to major constituents of the calpain-calpastatin system. Bovine aortic muscle contained only calpain II by activity measurements, Western blot of tissue extracts and Northern blot of poly(A)+ RNA. On the other hand, using the same methodologies, both calpains I and II as well as the 110 kDa inhibitor protein, calpastatin, were identified in cultured bovine aortic cells of smooth muscle origin. We conclude that the phenotypic state of smooth muscle cells is associated with differential expression of major components of the calpain-calpastatin system. Moreover, bovine aortic muscle is the only tissue identified to date that contains calpain II exclusively.
血管平滑肌含有大量的钙（2+）依赖性蛋白酶钙蛋白酶II。在本研究中，我们就钙蛋白酶-钙蛋白酶抑制蛋白系统的主要成分，比较了牛主动脉肌（肌肉表型）和平滑肌来源的培养牛主动脉细胞（调节表型）。通过活性测定、组织提取物的蛋白质印迹和聚腺苷酸（A）+RNA的Northern印迹分析，牛主动脉肌仅含有钙蛋白酶II。另一方面，使用相同的方法，在平滑肌来源的培养牛主动脉细胞中鉴定出了钙蛋白酶I和II以及110kDa的抑制蛋白钙蛋白酶抑制蛋白。我们得出结论，平滑肌细胞的表型状态与钙蛋白酶-钙蛋白酶抑制蛋白系统主要成分的差异表达有关。此外，牛主动脉肌是迄今为止唯一被鉴定为仅含有钙蛋白酶II的组织。
