Cellular location of N-acetyltransfer activities toward glucosamine and glucosamine-6-phosphate in cultured human skin fibroblasts

Abstract

The intracellular location in normal human cultured skin fibroblasts of the N-acetyltransferase activities that transfer the acetyl group from acetyl-CoA to the 2-amino group of glucosamine and glucosamine-6-phosphate have been investigated. Organelles have been separated using a combination of differential centrifugation and free flow electrophoresis. The intracellular distribution of the enzyme involved in the N-acetyltransfer to glucosamine and an alpha-glucosaminide disaccharide indicated that this enzyme activity concentrates mainly with lysosomal organelles whereas the activity associated with N-acetyltransferase to glucosamine-6-phosphate is non-lysosomal. It is proposed that acetyl-CoA: alpha-glucosaminide N-acetyltransferase may be used as a convenient enzyme marker of lysosomal organelle membranes.