【摘要】 该文研究了甘氨酰辅氨酸二肽氨基肽酶（GPDAEC．3．4．14．5）的最适反应条件，9次测定米氏常数（Km）值为（1．91±0．08）mmol／L，选用158mmol／LTris、64mmol/L，双甘氨肽，10mmol／L底物，pH8．6缓冲液，同时建立了手工法和自动化分析法，酶促反应速度在70min内呈线性，酶活力用手工法在750IU／L，内成线性，自动化分析法在1300IU/L，以下成线性，三份高、中、低值酶活力标本手工法及自动化分析法批内变异系数分别为1．7％～3．1％和0．7％～1．4％，批间变其分别为3.8％～6．7％和1．2％～4．4％。132例正常人GPDA为185．2±28．6（x±s），65例原发性肝癌组为408．0±216．1（x±s）明显高于正常组（P＜0．001）且与AFP水平无相关意义（r＝0．0361）．24例胃癌和59例肺癌分别为（99．5±16．6）IU／L和（11．8±23．0）IU／L，明显伏于正常组（P＜0．001）；并发现GPDA在食道癌及有门癌病人亦有下降趋势（P＜0．01）。更多还原

【Abstract】 This paper reports the optimal conditions for the determination of glycylproline dipeptidyl aminopeptidase (GPDA, EC, 3. 4. 14. 5 ). The determined Km value was (1. 91± 0. 08)mmol/L. The enzymatic reactions increased in a linear manner, and when measured with a manual and an automatic analyzer were found to be below 750 and 1 300IU/L respectively. Serum GPDA in 132 healthy subjects was (185. 2±28. 6) IU/L (x ±s ). The GPDA activity in sera from 65 patients with primary hepatic cancer was significantly higher at (408.0±216.1) IU/L x ±s) (P ＜0.001). No correlation with alphafetoprotein was found (r = 0. 0361). The GPDA levels in 24 gastric cancer patients and 59 lung cancer patients were (99. 5±16. 6) IU/L and (11.8±23.0) IU/L, respectively, and were significantly lower than those of the healthy controls (P＜0.001). The GDPA activity in sera appears to be decreased in patiCnts with esophageal cardiac cancers (P＜0.01).更多还原