title: Purification and physiocochemical properties of an extra-cellular cycloamylose (cyclodextrin) glucanotransferase from Bacillus macerans.
abstract: An extracellular cycloamylose (cyclodextrin) glucanotransferase (EC 2.4.1.19) from Bacillus macerans was purified to homogeneity by adsorption on starch, ammonium sulfate fractionation, column chromatography on DEAE-cellulose, and gel filtration on Sephadex G-100. The enzyme had a molecular weight of 67,000 and consisted of one polypeptide chain. The isoelectric point was pH 5.4. Temperature and pH optima were 60 degrees and 5.4--5.8, respectively. The purified enzyme was quite stable at 50 degrees (pH 6.0), but lost approximately 80% of its activity at 60 degrees for 30 min (pH 6.0). Prolonged digestion by trypsin did not affect the catalytic properties of the enzyme. The Km for starch was 5.7 mg/ml.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001407:Bacillus / Q000201:enzymology*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003505:Cyclodextrins; D005964:Glucosyltransferases / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight
chemical_list: D000596:Amino Acids; D003505:Cyclodextrins; D005964:Glucosyltransferases