Steven F S, Maier H, Talbot I C
Department of Biochemistry and Molecular Biology, School of Biological Sciences, University of Manchester, U.K.
J Enzyme Inhib. 1990;3(3):229-36. doi: 10.3109/14756369009035841.
We studied the enzymic status of the tumour cell surface protease, guanidinobenzoatase (GB) in frozen sections of a human colonic tumour grown in nude mice and also in human colons. Active enzyme was demonstrated by the binding of a synthetic fluorescent probe for the active centre of guanidinobenzoatase (GB). It was observed that tissue derived inhibitors of GB blocked the binding of this fluorescent probe and that enzyme inhibitor complex formation could be controlled by lowering the pH of the medium with lactic acid. The presence of an inhibitor of GB in the mouse tumour extract was taken advantage of by making two fluorescent derivatives of this inhibitor; both of which located GB on colonic tumour cells in frozen sections of human colon.
我们研究了在裸鼠体内生长的人结肠肿瘤以及人结肠的冰冻切片中肿瘤细胞表面蛋白酶——胍基苯甲酸酶（GB）的酶学状态。通过一种针对胍基苯甲酸酶（GB）活性中心的合成荧光探针的结合来证明活性酶的存在。据观察，GB的组织源性抑制剂会阻断这种荧光探针的结合，并且酶抑制剂复合物的形成可以通过用乳酸降低培养基的pH值来控制。利用小鼠肿瘤提取物中GB抑制剂的存在，制备了该抑制剂的两种荧光衍生物；这两种衍生物都能在人结肠冰冻切片中的结肠肿瘤细胞上定位GB。
