Purification and characterization of extracellular and cell wall bound beta-glucosidases from Aspergillus kawachii

• Published in: Bioscience, biotechnology, and biochemistry Vol. 62; no. 10; pp. 1938 - 1946
• Main Authors: Iwashita, K. (National Research Inst. of Brewing, Tokyo (Japan)), Todoroki, K, Kimura, H, Shimoi, H, Ito, K
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01-10-1998; Japan Society for Bioscience Biotechnology and Agrochemistry
• Subjects: Amino Acid Sequence; ASPERGILLUS; Aspergillus - enzymology; Aspergillus kawachii; beta-Glucosidase - chemistry; beta-Glucosidase - isolation & purification; beta-Glucosidase - metabolism; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; cell wall; Cell Wall - enzymology; CELL WALLS; CELLS; CELLULE; CELULAS; Food industries; Food microbiology; Fundamental and applied biological sciences. Psychology; GLUCOSIDASA; GLUCOSIDASE; GLUCOSIDASES; Humans; Mission oriented research; PARED CELULAR; PAROI CELLULAIRE; Physiology and metabolism; POLISACARIDOS; POLYHOLOSIDE; POLYSACCHARIDES; PURIFICACION; PURIFICATION; sugar chain; β-glucosidase; Temperature; Purification; Stability; Enzyme; Isozyme; Environmental factor; Biosynthesis; Extracellular; Cell wall; Bound form; Fungi; β-Glucosidase; Glycosidases; Substrate specificity; Microorganism culture; pH; Hydrolases; Fungi Imperfecti; O-Glycosidases; Comparative study; Physicochemical properties; Thallophyta
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.62.1938

We isolated two extracellular beta-glucosidases (EX-1: 145 kDa, EX-2: 130 kDa) and one cell ball bound beta-glucosidase (CB-1: 120 kDa) from Aspergillus kawachii and characterized their physical and kinetic properties. From the results of N-terminal amino acid sequence, enzymatic parameters and deglycosylation of the three purified enzymes, we strongly suggest that these three enzymes were products of the same gene, modified by different degree of glycosylation. All three purified beta-glucosidases adsorbed to the purified cell wall fraction of this strain. This association could dramatically improve the stability of purified enzymes. These three purified beta-glucosidases were readily inactivated even in moderate conditions but became very stable upon the addition of the purified cell wall fraction. The all purified beta-glucosidases were stable in the range of pH 2.0-9.0 and stable below 30 degrees C with 2mg/ml of the purified cell wall fraction