Some chemical characteristics of dimethylsuberimidate and its effect on sarcoplasmic reticulum vesicles

Sarcoplasmic reticulum vesicles treated with dimethylsuberimidate lose the capacity for ATP-promoted Ca2+ accumulation and show other properties indicative of leaky vesicles. As an aid to assessing whether this effect was caused by cross-linking or by hydrolysis products, characteristics of dimethylsuberimidate hydrolysis under incubation conditions used were measured. At pH 7.0, 25 DEGREES C, dimethylsuberimidate is hydrolyzed with an apparent first order rate constant of 0.016 min-1, to give dimethylsuberate as the principal product. The effect on ATP-promoted Ca2+ accululation was shown to be caused by partially and fully hydrolyzed products of the diimido ester, and not to cross-linking of membrane components.