Transition state analysis of NAD~+ hydrolysis by the cholera toxin catalytic subunit

摘要

The transition state for NAD~+ (oxidized nicotinamide adenine dinucleotide) hydrolysis by the cholera toxin Al polypeptide (CTA) has been characterized by multiple V/K kinetic isotope effects (KIEs) using labeled NAD~+ as the substrate. CTA causes cholera by catalyzing the ADP-ribosylation of the signal-transducing G_Sα protein.