Propenyl-L-NIO (hydrochloride) (ENIPO) is a potent, selective inhibitor of iNOS. The Ki values for inhibition of iNOS, nNOS, and eNOS by ENIPO are 17, 10.3 and 58.2 µM, respectively, as determined using initial rate binding kinetics.1 However, ENIPO is a time-dependent inhibitor that, with longer incubations, demonstrates reversible tight binding inhibition that is selective for iNOS over nNOS or eNOS. This selectivity results from iNOS exhibiting a 4-fold faster binding and 10-fold slower dissociation with ENIPO compared to nNOS.1 Ki values for ENIPO binding to iNOS and nNOS are 0.56 and 6 µM, respectively.1 Accurate determination of the Ki value of ENIPO for eNOS has not been determined but is expected to be 50-fold less than iNOS.1WARNING This product is not for human or veterinary use.
