Endo F, Matsuda I, Ogata A, Tanaka S
Pediatr Res. 1982 Mar;16(3):227-31. doi: 10.1203/00006450-198203000-00013.
Biochemical studies on human prolidase (EC 3.4.13.9) and prolidase deficiency are described. The urine sample from a 32-year-old female with prolidase deficiency was examined. Diagnosis was based on clinical features and defects of prolidase in her erythrocytes. She excreted massive amounts of iminopeptides, where three major peptides were identified; aspartyl-proline, glutamyl-proline and glycyl-proline. The prolidase was purified approximately 10,000-fold from the normal human erythrocytes through an eight step procedure. The purified enzyme consisted of two identical subunits of which the molecular weight was calculated to be 55,000. The relative cleavage rates of the enzyme for glycyl-L-proline, L-alanyl-L-proline, L-leucyl-L-proline, L-prolyl-L-proline, and glycyl-hydroxy-L-proline were 100%, 53%, 27%, 31% and 2%, respectively. The relative substrate specificity of the enzyme offers a reasonable explantation for the presence of a higher level of urinary imidodipeptides in a patient with prolidase deficiency. An attempt at erythrocyte transfusion was performed, aimed at enzyme replacement therapy. After the transfusion (erythrocytes from 800 ml of whole blood), the prolidase activity of the peripheral erythrocyte was elevated to approximately 35% of the normal values and gradually decreased (half-life, 41 days). During this period urinary peptide-bound proline was monitored, but no significant change was observed.
本文描述了对人氨肽酶（EC 3.4.13.9）及氨肽酶缺乏症的生化研究。对一名32岁氨肽酶缺乏症女性的尿液样本进行了检测。诊断基于临床特征及她红细胞中氨肽酶的缺陷。她排泄出大量的亚氨肽，其中鉴定出三种主要肽；天冬氨酰 - 脯氨酸、谷氨酰 - 脯氨酸和甘氨酰 - 脯氨酸。通过八步程序从正常人红细胞中纯化氨肽酶约10000倍。纯化后的酶由两个相同的亚基组成，计算其分子量为55000。该酶对甘氨酰 - L - 脯氨酸、L - 丙氨酰 - L - 脯氨酸、L - 亮氨酰 - L - 脯氨酸、L - 脯氨酰 - L - 脯氨酸和甘氨酰 - 羟基 - L - 脯氨酸的相对裂解率分别为100%、53%、27%、31%和2%。该酶的相对底物特异性为氨肽酶缺乏症患者尿液中较高水平的亚氨基二肽的存在提供了合理的解释。尝试进行红细胞输血，旨在进行酶替代治疗。输血后（来自800毫升全血的红细胞），外周红细胞的氨肽酶活性升高至正常值的约35%，并逐渐下降（半衰期为41天）。在此期间监测了尿中肽结合脯氨酸，但未观察到明显变化。
