可溶性固定化木瓜蛋白酶的制备及性质研究  

Preparation and properties of soluble immobilized papain

作　　者：李灵玲[1] 张涛[2] 余蓉[1] 

机构地区：[1]四川大学华西药学院,四川成都610041 [2]成都医学院生物化学教研室,四川成都610083

出　　处：《华西药学杂志》2007年第2期177-179,共3页West China Journal of Pharmaceutical Sciences

摘　　要：目的制备一种可溶性固定化木瓜蛋白酶(PP)并研究其部分酶学性质。方法将PP偶联在羧甲基纤维素醋酸琥珀酸酯(AS-L)上,制备得到水溶性固定化PP,并测定游离和水溶性固定化PP最适作用pH、最适作用温度、Km值、热稳定性、酸碱稳定性、低温稳定性和回收稳定性。结果最适作用pH分别为6.0、5.0,最适作用温度分别为60℃、70℃,Km值分别为2.53、3.07 mg.m l-1;可溶性固定化PP在60℃条件下,保温12 h,仍有62%的活性;在4℃条件下,30 d后活性保留达90%以上;在pH6时稳定性最好,pH4-7范围内也较稳定(相对活性>80%)。结论可溶性固定化PP能够在大于pH5.5的溶液中完全溶解,最适作用pH范围变窄,最适作用温度和Km值升高;热和酸碱的稳定性均明显增强。OBJECTIVE To prepare a soluble immobilized papain and determine its enzymatic properties. METHODS The soluble immobilized papain was obtained by conjugating the papain with the hydrophilic high molecular polymer carbexylmetbyl cellulose acetic succinate . Then the optimum pH and temperature,the Km value, the thermodynamic stability, the acid - base stability,the low temperature stability and operational stability of immobilized and soluble papains were determined, respectively. RESULTS The optimun pH of soluble and immobilized papain were 6. 0 and 5.0. Their optimum temperatures were 60℃ and 70℃. Their Km values were 2. 53 and 3.07 mg·ml^ -1. Under 60℃, after 12 hours the relative activity of immobilized papain was 62%. Under 4℃, after 30 days the relative activity was still over 90%. Under the pH6. 0, after 72 hours the activity of immobilized papain didn＇ t decrease, and betweeen pH4 and 7 its stability was high （ relative activity was over 80% ）. CONCLUSION Soluble immobilized papain can fully solubilize above the pH5.5. After immobilization the optimum pH range of papain decreased, and its optimum temperature, Km value and stabilities were all higher than before. Its thermodynamtic stability and the acid - base stability were also strengthened than before.

关 键 词：可溶性固定化酶 木瓜蛋白酶 酶学性质 偶联 

分 类 号：Q503[生物学—生物化学] Q556.3