Shima H, Yamanouchi M, Omori K, Sugiura M
Research Laboratory of Applied Biochemistry, Tanabe Seiyaku Co. Ltd., Osaka, Japan.
Biochem Mol Biol Int. 1995 Jul;36(3):513-9.
A proteinous fraction that produces endothelin-1 (ET-1) from big ET-1 in guinea-pig lung cytosol is described. An active protein has been successfully purified to homogeneity by combinations of sequential column chromatographies. The purified enzyme was a metalloenzyme based upon its sensitivity to chelating agent, and a molecular mass of the enzyme was 38 kDa estimated by gel filtration and SDS-PAGE. Further investigations revealed that the enzyme activity was abolished by sulfhydryl modifier such as N-ethylmaleimide, but inhibited neither by phosphoramidon, by thiorphan nor by captopril. The enzyme actually produced ET-1 with the Km value of 14.5 microM for big ET-1. These results indicate that this enzyme seems to be a novel metalloprotease that converts big ET-1 to ET-1.
本文描述了一种能从豚鼠肺胞质溶胶中的大内皮素-1（big ET-1）产生内皮素-1（ET-1）的蛋白质组分。通过连续柱色谱法的组合，一种活性蛋白已成功纯化至同质。基于其对螯合剂的敏感性，纯化后的酶为金属酶，通过凝胶过滤和SDS-PAGE估计该酶的分子量为38 kDa。进一步研究表明，该酶活性被巯基修饰剂如N-乙基马来酰亚胺消除，但不受磷酰胺、硫磷酰胺或卡托普利抑制。该酶实际产生ET-1，对big ET-1的Km值为14.5 microM。这些结果表明，这种酶似乎是一种将big ET-1转化为ET-1的新型金属蛋白酶。
