The Special Feature of Calponin on Myosins Phosphorylated by MLCK and PKA Respectively  

作　　者：JingxianYang ShuyuanLi GuozhuHan YuanLin 

机构地区：[1]DepartmentofPharmacology,DalianMedicalUniversity,Dalian116027,China

出　　处：《Journal of Nanjing Medical University》2005年第3期111-115,共5页南京医科大学学报（英文版）

基　　金：ThisworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina(No.30070203)

摘　　要：Objective: To reveal the special feature of calponin (CaP) on myosins of different states. Methods: Myosin phosphorylation determination, myosin Mg^(2+)-ATPase measurement and protein binding assay were used in this study. The lowest CaP/myosin ratio used in the assay was 1/10000(mol/mol), which was 10 thousands-fold lower than the CaP/myosin ratio used in previous studies. Results: In the absence of actin, micro-amount of calponin (MAC) stimulated the Mg^(2+)-ATPase activities of myosin in different states slightly but significantly; and more importantly, MAC significantly increased the precipitations of unphosphorylated myosin, Ca^(2+)-dependently and independently phosphorylated myosins by MLCK but not the myosin phosphorylated by PKA. Conclusion: MAC has a high efficient and selective effect on myosin in the absence of actin.Objective: To reveal the special feature of calponin (CaP) on myosins of different states. Methods: Myosin phosphorylation determination, myosin Mg^(2+)-ATPase measurement and protein binding assay were used in this study. The lowest CaP/myosin ratio used in the assay was 1/10000(mol/mol), which was 10 thousands-fold lower than the CaP/myosin ratio used in previous studies. Results: In the absence of actin, micro-amount of calponin (MAC) stimulated the Mg^(2+)-ATPase activities of myosin in different states slightly but significantly; and more importantly, MAC significantly increased the precipitations of unphosphorylated myosin, Ca^(2+)-dependently and independently phosphorylated myosins by MLCK but not the myosin phosphorylated by PKA. Conclusion: MAC has a high efficient and selective effect on myosin in the absence of actin.

关 键 词：micro-amount of calponin myosin phosphorylation myosin Mg^(2+)-ATPase activity precipitation 

分 类 号：Q51[生物学—生物化学]