EFFECT OF N,N-DIMETHYLALKYLAMINE N-OXIDES ON THE ACTIVITY OF PURIFIEDSARCOPLASMIC-RETICULUM (CA-MG)ATPASE

Amphiphilic N,N-dimethylalkylamine N-oxides (abbreviation CnNO, n is t he number of carbon atoms in the alkyl substituent) modulate the activ ity of the purified sarcoplasmic reticulum (Ca-Mg)ATPase. The phase of insensivity or slight stimulation of the activity at lower homologue concentrations is followed by the inhibition phase at higher concentra tions. The potency to inhibit the activity at high concentrations is m aximal for the homologue with the alkyl chain length n = 16. The inhib ition could be caused by the binding of homologues to binding sites at the protein/lipid bilayer interface.