肌球蛋白轻链激酶CaM结合位点突变体对肌球蛋白ATP酶活性的影响  

Effects of Calmodulin-binding site mutant of myosin light chain kinase on myosin ATPase activity

作　　者：赵莹[1] 张月[2] 吕广艳[1] 王辉[1] 崔颖[1] 魏晓晴[1] 陈海波[1] 高颖[1,2] 

机构地区：[1]辽宁省医学细胞分子生物学重点实验室,辽宁大连116044 [2]大连医科大学生化教研室,辽宁大连116044

出　　处：《现代生物医学进展》2009年第18期3419-3421,共3页Progress in Modern Biomedicine

基　　金：国家自然科学基金资助项目(30470394)

摘　　要：目的:探讨肌球蛋白轻链激酶(MLCK)钙调蛋白(CaM)结合位点突变体对肌球蛋白ATP酶活性的影响。方法:构建牛胃重组全长野生型MLCKCaM结合位点突变型蛋白(△CaM/MLCK);孔雀绿方法检测△CaM/MLCK对肌球蛋白的Mg2+-ATP酶活性的影响。结果:在无Ca2+/CaM存在时,随着△△CaM/MLCK浓度的增加,非磷酸化肌球蛋白的Mg2+-ATP酶活性明显增加;而磷酸化肌球蛋白的Mg2+-ATP酶活性明显降低。结论:△CaM/MLCK对肌球蛋白Mg2+-ATP酶活性的影响表明MLCK具有非激酶活性。Objective： To investigate the effect of calmodulin-binding site mutant of myosin light chain kinase on myosin ATPase activity. Methods： The recombinant calmodulin-binding site mutant of MLCK （△CaM/MLCK） was expressed. The effect of △CaM/MLCK on myosin Mg^2＋-ATPase activity was detected by Malachite Green method. Results： The △CaM/MLCK increased the unphosphorylated myosin Mg^2＋-ATPase activity but decreased the phosphorylated myosin Mg^2＋-ATPase activity in the absence of Ca^2＋/CaM. Conclusions： MLCK has non-kinase activity that increases unphosphorylated myosin Mg^2＋-ATPase activity and decreases phosphorylated myosin Mg^2＋-ATPase activity in the absence of Ca^2＋/CaM.

关 键 词：MLCK △CaM/MLCK 肌球蛋白 ATP酶活性 

分 类 号：Q593[生物学—生物化学] Q75