S Yang1, X M Zhang, M H Jiang. 1. Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai 200032, China. mhjiang@shmu.edu.cn
Abstract
AIM: To investigate the effect of melittin (Mel) of Na+,K+-ATPase activity and it's kinetic mode of action on guinea pig myocardial mitochondria. METHODS: Effect of Mel on heart mitochondrial Na+,K+-ATPase activity was determined with colorimetry method. RESULTS: Mel inhibited Na+,K+-ATPase in a concentration and time dependent manner, IC50 was 2.60 micromol/L. Kinetic studies of interaction between Mel and K+, Na+, ATP revealed that inhibitory effect of Mel was competitive with K+, but not with Na+ and ATP. CONCLUSION: Mel polypeptide potently inhibits Na+,K+-ATPase, possibly by binding to the K+ site.
AIM: To investigate the effect of melittin (Mel) of Na+,K+-ATPase activity and it's kinetic mode of action on guinea pig myocardial mitochondria. METHODS: Effect of Mel on heart mitochondrial Na+,K+-ATPase activity was determined with colorimetry method. RESULTS: Mel inhibited Na+,K+-ATPase in a concentration and time dependent manner, IC50 was 2.60 micromol/L. Kinetic studies of interaction between Mel and K+, Na+, ATP revealed that inhibitory effect of Mel was competitive with K+, but not with Na+ and ATP. CONCLUSION: Mel polypeptide potently inhibits Na+,K+-ATPase, possibly by binding to the K+ site.