摘要
①目的确定Ｌ－亮氨酸（Ｌ－Ｌｅｕ）对人类胎盘碱性磷酸酶（ＰＬＡＰ）的抑制类型，并探讨其抑制机理。②方法应用分光光度法分别测定有Ｌ－Ｌｅｕ和无Ｌ－Ｌｅｕ存在下的酶活力，根据其活力变化求出酶的相对活力；用双倒数作图法，确定Ｌ－Ｌｅｕ对ＰＬＡＰ的抑制类型并求出其抑制常数（Ｋｉ）；同时也观察了ｐＨ对抑制作用的影响。③结果Ｌ－Ｌｅｕ对ＰＬＡＰ有明显地抑制作用，抑制程度与ｐＨ有关；双倒数作图得到一组平行线，Ｋｉ为１．９８ｍｍｏｌ／Ｌ．④结论Ｌ－Ｌｅｕ是ＰＬＡＰ的反竞争性抑制剂。
Objective To determine the inhibition type of L leucine( L Leu) on human placental alkaline phosphatase (PLAP) and discuss the molecular mechanism underlying the inhibition activity. Methods Spectrophotometry was used to study the activity of PLAP in the presence and absence of L Leu. PLAP relative activity was calculated according to the absorbance variation. The inhibition type and inhibition constant (Ki) of L Leu on PLAP were determined by using the double reciprocal plot. The effect of pH on L Leu inhibition activity was studied. Results The activity of PLAP was obviously inhibited by L leu. A group of parallel lines was obtained by using the double reciprocal plot. The inhibition constant (Ki) was 1.98mmol/L. Conclusion L Leu is an uncompetitive inhibitor of PLAP. The ihhibition activity on PLAP was affected by the pH of solutions.
出处
《青岛医学院学报》
1998年第1期1-3,共3页
Acta Academiae Medicinae Qingdao Universitatis
基金
山东省卫生厅科研基金
