An unstudied β--acetylhexosaminidase (SnHex) from the soil bacterium was successfully cloned and subsequently expressed as a soluble protein in . Activity tests and the biochemical characterization of the purified protein revealed an optimum pH of 6.0 and a robust thermal stability at 50 °C within 24 h. The addition of urea (1 M) or sodium dodecyl sulfate (1% /) reduced the activity of the enzyme by 44% and 58%， respectively， whereas the addition of divalent metal ions had no effect on the enzymatic activity. PUGNAc (-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino--phenylcarbamate) strongly inhibited the enzyme in sub-micromolar concentrations. The β--acetylhexosaminidase was able to hydrolyze β1，2... More
An unstudied β--acetylhexosaminidase (SnHex) from the soil bacterium was successfully cloned and subsequently expressed as a soluble protein in . Activity tests and the biochemical characterization of the purified protein revealed an optimum pH of 6.0 and a robust thermal stability at 50 °C within 24 h. The addition of urea (1 M) or sodium dodecyl sulfate (1% /) reduced the activity of the enzyme by 44% and 58%， respectively， whereas the addition of divalent metal ions had no effect on the enzymatic activity. PUGNAc (-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino--phenylcarbamate) strongly inhibited the enzyme in sub-micromolar concentrations. The β--acetylhexosaminidase was able to hydrolyze β1，2-linked， β1，3-linked， β1，4-linked， and β1，6-linked GlcNAc residues from the non-reducing end of various tested glycan standards， including bisecting GlcNAc from one of the tested hybrid-type N-glycan substrates. A mutational study revealed that the amino acids D306 and E307 bear the catalytically relevant side acid/base side chains. When coupled with a chitinase， the β--acetylhexosaminidase was able to generate GlcNAc directly from colloidal chitin， which showed the potential of this enzyme for biotechnological applications.
