Li Li-Na, Wu Yu-Qing, Buchet René
State Key Laboratory for Supramolecular Structure and Materials, Jilin University, Changchun 130012, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 Oct;29(10):2820-3.
To evaluate the inhibition effect of dansyl-L-phenylalanine on calf intestinal alkaline phosphatase (CIAP), UV-Vis spectrophotometric method was employed. It was found that dansyl-L-phenylalanine can selectively inhibit CIAP. The kinetic inhibition processes of dansyl-L-phenylalanine and L-phenylalanine were comparatively studied. The authors' finding elucidates that at the optimized alkaline pH of alkaline phosphatase (pH 10.4) and 37 degrees C, dansyl-L-phenylalanine can inhibit alkaline phosphatase activity of CIAP efficiently and specifically, similar as L-phenylalanine. Both inhibition types were uncompetitive inhibition resulting from the double reciprocal curve fitting of upsilon versus substrate concentrations, and the inhibition constants Ki of both inhibitors were determined to be 2.3 and 1.1 mmol L(-1) respectively, both of which were at millimolar level. The investigation of the inhibition effect of dansyl modified L-phenylalanine on calf intestinal alkaline phosphatase not only helped get insight into the detailed inhibition mechanism of L-phenylalanine on tissue specific alkaline phosphatase, such as in the case of intestinal alkaline phosphatase, but also provided the possibility to employ fluorescence spectroscopy by labeling the specific inhibitors of alkaline phosphatase with chromophoric groups.
为评估丹磺酰-L-苯丙氨酸对小牛肠碱性磷酸酶（CIAP）的抑制作用，采用紫外可见分光光度法。结果发现丹磺酰-L-苯丙氨酸可选择性抑制CIAP。对丹磺酰-L-苯丙氨酸和L-苯丙氨酸的动力学抑制过程进行了比较研究。作者的研究结果表明，在碱性磷酸酶的最佳碱性pH值（pH 10.4）和37℃条件下，丹磺酰-L-苯丙氨酸与L-苯丙氨酸类似，能够有效且特异性地抑制CIAP的碱性磷酸酶活性。通过对υ与底物浓度的双倒数曲线拟合可知，两种抑制类型均为非竞争性抑制，两种抑制剂的抑制常数Ki分别测定为2.3和1.1 mmol L⁻¹，均处于毫摩尔水平。对丹磺酰修饰的L-苯丙氨酸对小牛肠碱性磷酸酶抑制作用的研究，不仅有助于深入了解L-苯丙氨酸对组织特异性碱性磷酸酶（如肠碱性磷酸酶）的详细抑制机制，还为通过用发色基团标记碱性磷酸酶的特异性抑制剂来采用荧光光谱法提供了可能性。
