Demmer W, Brand K
Biochem Biophys Res Commun. 1983 Jul 29;114(2):804-12. doi: 10.1016/0006-291x(83)90853-7.
A dipeptidyl carboxypeptidase activity has been localized in synaptic plasma membranes which have been prepared from isolated rat brain cortical synaptosomes. The specificity of this proteolytic activity towards various synthetic and biological active peptides is compared to the peptidase activities of intact synaptosomes. In contrast to the synaptosomal peptidases which are capable of cleaving all peptide bonds of Met-enkephalin-Arg6-Phe7 the peptidase activity associated with the synaptic plasma membrane exclusively hydrolyses a dipeptide from the carboxyl terminus of all hepta- and hexapeptides tested. The fact that this dipeptidyl carboxypeptidase does not cleave the Gly3-Phe4 peptide bond of Met-enkephalin suggests that this enzyme is different from "enkephalinase". The synaptic membrane dipeptidyl carboxypeptidase is inhibited by metal chelating agents and thiols but is not affected by compounds known to inhibit serine proteases, thermolysin and "enkephalinase".
一种二肽基羧肽酶活性已定位在从分离的大鼠脑皮质突触体制备的突触质膜中。将这种蛋白水解活性对各种合成和生物活性肽的特异性与完整突触体的肽酶活性进行比较。与能够切割甲硫氨酸脑啡肽-精氨酸6-苯丙氨酸7所有肽键的突触体肽酶不同，与突触质膜相关的肽酶活性仅从所有测试的七肽和六肽的羧基末端水解一个二肽。这种二肽基羧肽酶不切割甲硫氨酸脑啡肽的甘氨酸3-苯丙氨酸4肽键这一事实表明该酶与“脑啡肽酶”不同。突触膜二肽基羧肽酶受到金属螯合剂和硫醇的抑制，但不受已知抑制丝氨酸蛋白酶、嗜热菌蛋白酶和“脑啡肽酶”的化合物影响。
