Secretion of beta-N-acetylglucosaminidase isoenzymes by cultured cystic fibrosis fibroblasts

Abstract

Secretion of the lysosomal enzyme beta-N-acetylglucosaminidase (EC 3.2.1.30) by normal and cystic fibrosis fibroblasts has been compared. In contrast to an earlier report, no differences were found in either the rate of secretion, or in the molecular forms of the enzyme secreted by normal fibroblast cultures and cultures initiated from patients with cystic fibrosis. The B isoenzyme of beta-N-acetylglucosaminidase from cystic fibrosis fibroblasts was converted to a more negatively charged form during preincubation for 3 h at pH 5.0 and 37 degrees C. The enzyme from normal fibroblasts was unaffected by this treatment.