摘要
催化血浆中游离胆固醇酯化反应的卵磷脂胆固醇酰基转移酶(LCAT)是胆固醇逆向运输过程中的关键酶之一。本研究针对原测定方法中本底过高的问题,改变了对照本底的反应条件,使原反应体系中的前两步酶反应无法进行,最终测得的反应速率真实地反映了样品中本底(甘油-3-磷酸)的水平。经改进的测定方法除成功地用于人血清测定外,还应用于细胞培养液和兔血清的测定,对于相关药物的研究和筛选具有实际应用价值。
Lecithin:cholesterol acyltransferase (LCAT) is a key enzyme in reverse cholesterol transport, which catalyzes the esterification of free cholesterol in human plasma. In most of the methods, an artificial liposome is served as the substrate for LCAT and the enzyme activity is measured by the radioactivity incorporated into the cholesterol ester generated, which limits the use of LCAT assay in clinical test and drug screening with a large number of samples. LCAT activity was determined by an endogenous selfsubstrate method in a series of enzyme catalyzed reactions developed by Imamura Shigeyuki with an extraordinarily high blank level. To resolve this problem, the reaction system was investigated and it was found that the incomplete inhibition of LCAT activity by Triton X100 resulted in the unusual phenomenon. So, the first two enzymatic reactions following the LCAT catalyzed reaction were omitted in the blank measurement, and the NADH reduction was only due to the glycero3phosphate present in the sample solution. After the improvement, this system was applied successfully in cell culture medium and rabbit serum. So, this is a practical method in drug screening and other fields related to LCAT metabolism.
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2003年第2期152-155,共4页
Journal of East China University of Science and Technology
