摘要
分别以磷酸苏氨酸多肽(K-R-pT-I—R—R)和4-硝基苯基磷基二钠盐(pNPP)为底物,研究原核表达的日本血吸虫丝/苏氨酸蛋白磷酸酶重组蛋白rSjPP的酶活性,检测二价金属阳离子(Mn^2+、Ni^2+、Mg^2+、Ca^2+)、温度、pH值对rSjPP酶活性的影响。结果显示,rSjPP重组蛋白可以有效地水解磷酸苏氨酸多肽,具有丝/苏氨酸蛋白磷酸酶活性。rSjPP酶活性的最适温度为60℃,最适pH值为8.0。1~4mmol/L Ni^2+对rSjPP酶活力有促进作用,但Mn^2+、Mg^2+、Ca^2+等阳离子对rSjPP的酶活力影响不大。
Using phosphothreonine polypeptide K-R-pT-I-R-R as substrate, the activities of Ser/Thr protein phosphatase (rSjPP) of Schistosoma japonicum expressed in Escherichia coli were tested. The effects of temperature,pH value,divalent cations(Mn^2+ ,Ni^2+ ,Mg^2+ ,and Ca^2+) on the enzymatic activities of the rSjPP were analyzed using pNPP as substrate. The phosphothreonine polypeptide could been hydrolyzed by the rSjPP,indicating that the rSjPP possessed the characteristics of Ser/Thr protein phosphatase. Using pNPP as substrate,rSjPP had the strongest catalytic activities under the condition of pH8.0 and 60℃. The activities of rSjPP could be enhanced by adding Ni^2+ from 1 mmol/L to 4 mmol/L but not by Mn^2+ ,Mg^2+ ,and Ca^2+.
出处
《中国兽医科学》
CAS
CSCD
北大核心
2008年第7期555-558,共4页
Chinese Veterinary Science
基金
国家高技术研究发展计划(863)项目(2006AA10A207)
国家“十一五”科技支撑计划项目(2006BAD06A09)
关键词
日本血吸虫
丝/苏氨酸蛋白磷酸酶
酶活性
影响因子
Schistosoma japonicura
Ser/Thr protein phosphatase
enzymatic activity
impact factor