Supattapone S, Fricker L D, Snyder S H
J Neurochem. 1984 Apr;42(4):1017-23. doi: 10.1111/j.1471-4159.1984.tb12705.x.
Enkephalin convertase, the enkephalin-synthesizing carboxypeptidase B-like enzyme, has been purified to apparent homogeneity from bovine pituitary and adrenal chromaffin granule membranes. The membrane-bound enkephalin convertase can be solubilized in high yield with 0.5% Triton X-100 in the presence of 1 M NaCl. Extensive purification is achieved by affinity chromatography with p-aminobenzoyl-L-arginine linked to Sepharose 6B. Enzyme purified from both pituitary and adrenal chromaffin granule membranes shows a single band by sodium dodecyl sulfate polyacrylamide gel electrophoresis with an apparent molecular weight of 52,500, whereas enkephalin convertase purified from soluble extracts of these tissues has an apparent molecular weight of 50,000. The regional distribution of the membrane-bound enzyme in the rat brain differs from that of the soluble enzyme. While the soluble enzyme shows 10-fold variations, resembling somewhat the enkephalin peptides, membrane-bound enkephalin convertase is more homogeneously distributed throughout the brain. In rat pituitary glands, membrane-bound enzyme activity is similar in the anterior and posterior lobes, whereas the soluble enzyme is enriched in the anterior lobe. Membrane-bound and soluble forms of enkephalin convertase isolated from either bovine pituitary glands or adrenal chromaffin granules show identical substrate and inhibitor specificities. As with the soluble enzyme, membrane-bound enkephalin convertase hydrolyzes [Met]- and [Leu]enkephalin-Arg6 and -Lys6 to enkephalin, with no further degradation of the pentapeptide.
脑啡肽转换酶，一种合成脑啡肽的羧肽酶B样酶，已从牛垂体和肾上腺嗜铬颗粒膜中纯化至表观均一。在1 M氯化钠存在下，膜结合的脑啡肽转换酶可用0.5% Triton X-100以高产率溶解。通过用与琼脂糖6B相连的对氨基苯甲酰-L-精氨酸进行亲和层析实现广泛纯化。从垂体和肾上腺嗜铬颗粒膜纯化的酶在十二烷基硫酸钠聚丙烯酰胺凝胶电泳中显示出一条带，表观分子量为52,500，而从这些组织的可溶性提取物中纯化的脑啡肽转换酶的表观分子量为50,000。大鼠脑中膜结合酶的区域分布与可溶性酶不同。虽然可溶性酶表现出10倍的变化，有点类似于脑啡肽肽，但膜结合的脑啡肽转换酶在整个大脑中分布更均匀。在大鼠垂体中，膜结合酶活性在前叶和后叶相似，而可溶性酶在前叶中富集。从牛垂体或肾上腺嗜铬颗粒中分离的膜结合和可溶性形式的脑啡肽转换酶显示出相同的底物和抑制剂特异性。与可溶性酶一样，膜结合的脑啡肽转换酶将[Met]-和[Leu]脑啡肽-Arg6和-Lys6水解为脑啡肽，五肽不再进一步降解。
