Butterworth J, Priestman D
J Inherit Metab Dis. 1984;7(1):32-4. doi: 10.1007/BF01805618.
Skin fibroblasts have a single enzyme, Mn2+-activated prolidase, that hydrolyses a range of amino acid-proline dipeptides. Two cases of prolidase deficiency showed a marked loss of activity against glycyl-proline irrespective of Mn2+ conditions. However, the abnormal enzyme showed only moderate reductions in activity against phenylalanyl-, alanyl-, and leucyl-proline following preincubation with Mn2+ or addition of Mn2+ with the substrate. Control prolidase was stable to prolonged preincubation with Mn2+, whereas the abnormal prolidase was progressively inactivated. The findings indicate, for at least the present two cases, that prolidase deficiency results from an altered rather than a marked reduction in the amount of normal enzyme.
皮肤成纤维细胞有一种单一的酶，即锰离子激活的脯氨酰二肽酶，它能水解一系列氨基酸 - 脯氨酸二肽。两例脯氨酰二肽酶缺乏症患者，无论锰离子条件如何，对甘氨酰 - 脯氨酸的活性都显著丧失。然而，这种异常酶在与锰离子预孵育或与底物一起添加锰离子后，对苯丙氨酰 - 、丙氨酰 - 和亮氨酰 - 脯氨酸的活性仅适度降低。对照脯氨酰二肽酶对长时间与锰离子预孵育稳定，而异常脯氨酰二肽酶则逐渐失活。这些发现表明，至少就目前这两例而言，脯氨酰二肽酶缺乏症是由正常酶量的改变而非显著减少所致。
