Birckbichler P J, Orr G R, Conway E, Patterson M K
Cancer Res. 1977 May;37(5):1340-4.
Transglutaminase activity was determined in normal and transformed paired cell systems. Reduced enzyme activity was found in virus-transformed human and hamster cells and in chemically transformed mouse cells relative to normal counterparts. Most of the enzyme activity was localized in the particulate fraction sedimenting at 105,000 X g. Enzyme activity was highest when normal cell populations were in an essentially nonmitotic state. Protein capable of incorporating putrescine was present in normal and transformed human cells, although the rate of incorporation was lower in the latter. The putrescine acceptor in the normal cell paralleled enzyme activity and enzyme distribution. Trypsin (5 microng/ml) treatment of the normal cell resulted in a 3-fold increase in enzyme activity, which occurred independently of protein synthesis.
在正常和转化的配对细胞系统中测定了转谷氨酰胺酶活性。相对于正常对应细胞，在病毒转化的人和仓鼠细胞以及化学转化的小鼠细胞中发现酶活性降低。大部分酶活性定位于在105,000×g下沉淀的颗粒部分。当正常细胞群体处于基本非有丝分裂状态时，酶活性最高。正常和转化的人细胞中存在能够掺入腐胺的蛋白质，尽管后者的掺入速率较低。正常细胞中的腐胺受体与酶活性和酶分布平行。用胰蛋白酶（5微克/毫升）处理正常细胞导致酶活性增加3倍，这一增加独立于蛋白质合成而发生。
