SPECTROSCOPIC STUDIES OF INHIBITION OF CALMODULIN ACTIVITY BY SOME DRUGS

Abstract

The effect of four inhibitors on calmalulin (CuM) were studied by a ftuorescence and ultraviolet techniques. Four compounds IN - ( 6 - aminohexyt) 5-chloro - I - napthalenesulphonamide] (W-7), 1 - [ bis - (4 - chtorophenyt) methyl] - 3 - [2, 4-dichloro - β - ( 2 , 4 - dichlorobenzyloxyl) phenethyt] imidazolium chloride (R24571), trifluoperazine (TFP) , thiodiphenylamide chloride (TDPAC) showed inhibitory effect on bovine brain phosphodiesterase (PDE) induced by CaM. The concentration of inhibitors producing 50% inhibition of of Ca 2+ / CaM activity activity (IC50) and the Hill coefficient were correlating closely between the methods, Ki's and thermodynamic parameters for these interactions were estimated.