Construction and functional characterization of truncated versions of recombinant keratanase II from Bacillus circulans

Abstract

There is a need for degradative enzymes in the study of glycosaminoglycans. Many of these enzymes are currently available either in their natural or recombinant forms. Unfortunately, progress in structure-activity studies of keratan sulfate (KS) have been impeded by the lack of a commercially available endo-β-N-acetylglucosaminidase, keratantase II. The current study uses a recently published sequence of a highly thermostable keratanase II identified in Bacillus circulans to clone and express a series of truncation mutants in Escherichia coli BL21. The resulting truncated forms of keratanase II exhibit activity and excellent storage and thermal stability making these useful tools for glycobiology research.

Keywords: Hydrolase; Keratan sulfate, glycosaminoglycan; Keratanase II; Mass spectrometry; Protein engineering.