INCREASED CALCIUM SENSITIVITY OF CHEMICALLY SKINNED HUMAN ATRIA BY MYOSIN LIGHT CHAIN KINASE

被引:31
作者
MORANO, I [1 ]
BACHLESTOLZ, C [1 ]
KATUS, A [1 ]
RUEGG, JC [1 ]
机构
[1] UNIV HEIDELBERG, INST PHYSIOL 2, NEUENHEIMER FELD 326, D-6900 HEIDELBERG, FED REP GER
关键词
D O I
10.1007/BF02005820
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
We investigated the influence of myosin P-LC phosphorylation catalysed by calcium/calmodulin-dependent myosin light chain kinase (MLCK) on the tension-pCa relation of chemically skinned human atrial fibres. MLCK-induced increased myosin P-LC phosphorylation sensitized human atrial skinned fibres for calcium by 0.11 pCa-units in patients with valvular heart disease, and by 0.05 to 0.07 pCa-units in patients with coronary heart disease. The MLCK effect could be antagonized by a light chain phosphatase. The protein phosphatase ocadiac acid (OA) had no influence on the tension-pCa relation of skinned human atrial fibres and had no potentiating effect together with MLCK. The MLCK preparation used in this study was from bovine ventricle and revealed a Km of 1.8 .times. 10-5 M and a Vmax of 822 nmol Pi/min/mg using purified bovine ventricular myosin-LCs as substrate.
引用
收藏
页码:350 / 359
页数:10
相关论文
共 35 条