Aoyagi T, Nagai M, Iwabuchi M, Liaw W S, Andoh T, Umezawa H
Cancer Res. 1978 Oct;38(10):3505-8.
Activities of various hydrolytic enzymes were determined in rat organ homogenates and on the surface of cells from various sources, i.e., tumor cell strains, primary cultured cells, normal cells, and their transformants. Alanine, leucine, methionine, phenylalanine, and glycyl-proline aminopeptidases and esterase showed relatively high activities in all these organs and cells. In the kidney homogenate the aminopeptidase A activity was higher in other organs; i.e., the aminopeptidase A activity was lower than that of aminopeptidase B. Normal cells derived from kidneys showed the kidney-type pattern of amino-peptidases A and B on the surface of cells, whereas tumor cells from various origins were of another organ type. When cultured mouse fibroblast strain C3H2K and rat fibroblast strain 3Y1 cells were transformed by SV40 or by a ts A mutant and maintained at permissive temperature, aminopeptidase A activity was drastically decreased, and the ratio of aminopeptidase A to aminopeptidase B was reduced to the levels of tumor cells. If the ts A mutant-transformed cells were grown at the restrictive temperature, the ratio approached that of normal cells. In normal cells, however, cultivation at high or low temperature did not cause any change of the activities.
在大鼠器官匀浆以及来自各种来源的细胞表面，即肿瘤细胞系、原代培养细胞、正常细胞及其转化细胞中，测定了各种水解酶的活性。丙氨酸、亮氨酸、蛋氨酸、苯丙氨酸以及甘氨酰 - 脯氨酸氨基肽酶和酯酶在所有这些器官和细胞中均表现出相对较高的活性。在肾脏匀浆中，氨基肽酶A的活性高于其他器官；也就是说，氨基肽酶A的活性低于氨基肽酶B。源自肾脏的正常细胞在细胞表面呈现出肾脏型的氨基肽酶A和B模式，而来自各种来源的肿瘤细胞则属于另一种器官类型。当培养的小鼠成纤维细胞系C3H2K和大鼠成纤维细胞系3Y1细胞被SV40或ts A突变体转化并在允许温度下维持时，氨基肽酶A的活性急剧下降，并且氨基肽酶A与氨基肽酶B的比例降低到肿瘤细胞的水平。如果ts A突变体转化的细胞在限制温度下生长，该比例接近正常细胞的比例。然而，在正常细胞中，在高温或低温下培养不会引起活性的任何变化。
