title: Some properties of a cyclomaltodextrin-glucanotransferase from Bacillus circulans DF 9 R type.
abstract: The cyclomaltodextrin-glucanotransferase (EC2.4.1.19, CGTase) which was purified to homogeneity from Bacillus circulans strain DF 9, R type, showed a pI of 5.3 determined by disc-isoelectric focusing, a Mw of 78 kDa estimated by SDS-PAGE with a range of pH of optimal enzymatic activity rather large (4.5-7.5). The thermal stability of the enzyme at 55 degrees C was increased 4-5 times when calcium ion (10 to 100 mM) or alpha-cyclodextrins (10 mM) were added to the preincubation mixtures. The alpha: beta: gamma ratio determined by HPLC was about 1:0.9:0.4 and the maximal conversion to cyclodextrins with 5% soluble starch was about 36%.
authors.affiliation: Instituto de Investigaciones Bioquímicas Luis F. Leloir Fundación Campomar, Buenos Aires, Argentina.
authors.forename: L R
authors.initials: LR
authors.lastname: Maréchal
authors.forename: A M
authors.initials: AM
authors.lastname: Rosso
authors.forename: M A
authors.initials: MA
authors.lastname: Maréchal
authors.forename: N
authors.initials: N
authors.lastname: Krymkiewicz
authors.forename: S A
authors.initials: SA
authors.lastname: Ferrarotti
mesh_terms: D001407:Bacillus / Q000145:classification / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D003505:Cyclodextrins / Q000096:biosynthesis / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D005964:Glucosyltransferases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008970:Molecular Weight; D012995:Solubility; D013213:Starch / Q000378:metabolism; D013696:Temperature; D047391:alpha-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D047391:alpha-Cyclodextrins; D013213:Starch; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase; D002118:Calcium; C032613:alpha-cyclodextrin