Separation of β- N-acetylglucosaminidase isoenzymes from liver and plasma of six mammalian species by DEAE-cellulose chromatography

Abstract

1. 1. The β- N-acetylglucosaminidase (EC 3.2.1.30) activities of human, pig, calf, lamb, rat and rabbit liver and plasma have been investigated. 2. 2. All preparations had maximum activity between pH 4.0 and 4.5 and K m values with the substrate 4-methylumbelliferyl-2-acetamido-2-deoxy-β- d-glucopyranoside ranged from 0.54 to 2.54 mM. 3. 3. The isoenzyme profiles of liver and plasma β- N-acetylglucosaminidase activity were compared using DEAE-cellulose chromatography. In all species the major anionic component of liver ( β- N-acetylglucosaminidase A) was eluted at a higher salt concentration than the most anionic plasma isoenzyme. 4. 4. The plasma β- N-acetylglucosaminidase A isoenzyme of all species contained sialic acid residues whereas only the rabbit, pig and calf liver isoenzymes were sialylated.