4.3.1.28 NAD(P)+ - 719691 4.3.1.28 NAD+ the enzyme has about 0.17 equivalents of tightly bound NAD+. In the presence of exogenous NAD+, the initial rate is elevated 8fold with a Km of 0.0023 mM for the cofactor 719643 4.3.1.28 NAD+ there is no requirement for an external cofactor for full activity, although sequence data indicate NAD+ as cofactor. NAD+ binds very tightly to the enzyme 719006