Kaempferol inhibits myosin light chain kinase.
Kaempferol, 3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one, was found to inhibit bovine aorta myosin light chain kinase with a Ki of 0.3-0.5 microM. It was found to be competitive with ATP and non-competitive with isolated myosin light chains. The specificity of this inhibitor was studied relative to protein kinase C and cAMP dependent protein kinase (IC50 = 15 microM and 150 microM, respectively). It appears not to interact strongly with calmodulin binding proteins, such as Ca2+-calmodulin dependent phosphodiesterase (IC50 = 45 microM), and had little effect on actin-activated myosin subfragment-1 ATPase activity (IC50 greater than 100 microM) or smooth muscle phosphatase activities (IC50 greater than 100 microM).
Rogers
J C
JC
Department of Biological Chemistry, Merck Sharp and Dohme Research Laboratories, West Point, PA 19486.
Williams
D L
DL
D000818:Animals; D001011:Aorta / Q000201:enzymology; D002147:Calmodulin / Q000494:pharmacology; D002417:Cattle; D005419:Flavonoids / Q000494:pharmacology*; D066298:In Vitro Techniques; D044949:Kaempferols; D009219:Myosin-Light-Chain Kinase / Q000037:antagonists & inhibitors*; D013379:Substrate Specificity
D002147:Calmodulin; D005419:Flavonoids; D044949:Kaempferols; C006552:kaempferol; D009219:Myosin-Light-Chain Kinase