1998 Volume 74 Issue 6 Pages 142-144
An attempt was made to confirm and develop the work of Kuwayama et al. (J. Biochem. 104, 862-866, 1988) which showed a significant discrepancy between myosin light chain kinase (MLCK) activity (K-activity) and actomyosin-activating activity (L-activity) of bovine stomach. A simple method of preparing 155 kDa protein identical with MLCK was presented. Preparations thus obtained showed high ratios of the L-activity to the K-activity, the highest being 230. This indicates that a mechanism other than the phosphorylation of light chain plays a crucial role on the molecular level in activating contractile processes of the actomyosin-ATP system.
