Human acetyl-coenzyme A:α-glucosaminide N-acetyltransferase: Kinetic characterization and mechanistic interpretation

Abstract

Acetyl-CoA:α-glucosaminide N-acetyltransferase (N-acetyltransferase) is an integral lysosomal membrane protein which catalyses the transfer of acetyl groups from acetyl-CoA on to the terminal glucosamine in heparin and heparan sulphate chains within the lysosome. In vitro, the enzyme is capable of acetylating a number of mono- and oligo-saccharides derived from heparin, provided that a non-reducing terminal glucosamine is present. We have prepared highly enriched lysosomal membrane fractions from human placenta by a combination of differential centrifugation and density-gradient centrifugation in Percoll. This preparation was used to investigate the kinetics of the enzyme with three acetyl-a..