Turzynski A, Mentlein R
Anatomisches Institut, Universität Kiel, Federal Republic of Germany.
Eur J Biochem. 1990 Jul 5;190(3):509-15. doi: 10.1111/j.1432-1033.1990.tb15603.x.
Based on the liberation of proline from ProLeuGlyNH2 (MIF-1, melanostatin) manganese-activated prolyl aminopeptidase activities were purified from rat brain and kidney cytosolic fractions. They were distinguished from other di- and tripeptidases and an arylamidase liberating N-terminal proline. Purified prolyl aminopeptidase from both sources had identical molecular properties (native Mr 300,000, subunit Mr 54,000) and very similar catalytic properties. The action of the purified enzymes was not restricted to proline. Other, in particular lipophilic, amino acids were cleaved from di-, tri- and oligopeptides with even higher velocities. Peptides with N-terminal penultimate proline residues were not degraded. From a comparison of molecular data, action on peptides, influence of pH values, inhibitors and activators, it is concluded that the activity is identical with leucyl aminopeptidase (EC 3.4.11.1) and that a separate prolyl aminopeptidase (EC 3.4.11.5) does not exist in rats.
基于从ProLeuGlyNH2（MIF-1，黑素抑制素）中释放出脯氨酸，从大鼠脑和肾胞质部分纯化出锰激活的脯氨酰氨基肽酶活性。它们与其他二肽酶、三肽酶以及一种释放N端脯氨酸的芳基酰胺酶区分开来。从这两种来源纯化得到的脯氨酰氨基肽酶具有相同的分子特性（天然分子量300,000，亚基分子量54,000）和非常相似的催化特性。纯化酶的作用并不局限于脯氨酸。其他氨基酸，尤其是亲脂性氨基酸，从二肽、三肽和寡肽上被切割下来的速度甚至更快。具有N端倒数第二个脯氨酸残基的肽不会被降解。通过对分子数据、对肽的作用、pH值的影响、抑制剂和激活剂的比较得出结论，该活性与亮氨酰氨基肽酶（EC 3.4.11.1）相同，并且大鼠中不存在单独的脯氨酰氨基肽酶（EC 3.4.11.5）。
