title: Study on the thermal stability of alpha-amylase modified by maleic anhydride copolymer.
abstract: The thermal inactivation of mesophilic Bacillus subtilis alpha-amylase modified by maleic anhydride/vinyl acetate copolymer has been studied at different polymer/enzyme ratios in the pH range of relevance to enzymatic catalysis. Enzymatic activity measurements combined with circular dichroism measurements were used to determine the enzyme thermostability. The apparent first-order rate constants and activation energies of thermo-inactivation affected by addition of Ca2+ ions as well as by modification have been calculated. The modified alpha-amylase exhibited sufficiently high catalytic activity with enhanced resistance to the thermal unfolding process.
authors.affiliation: Instituto di Chimica Generale dell'Universita, Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Brissová
authors.forename: J
authors.initials: J
authors.lastname: Augustín
authors.forename: M
authors.initials: M
authors.lastname: Simonetti
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry / Q000187:drug effects*; D002942:Circular Dichroism; D006358:Hot Temperature; D007700:Kinetics; D008298:Maleates / Q000494:pharmacology*; D008299:Maleic Anhydrides / Q000494:pharmacology*; D011145:Polyvinyls / Q000494:pharmacology*; D011489:Protein Denaturation; D000516:alpha-Amylases / Q000737:chemistry / Q000187:drug effects*
chemical_list: D001426:Bacterial Proteins; D008298:Maleates; D008299:Maleic Anhydrides; D011145:Polyvinyls; C090736:poly(vinyl acetate-maleic anhydride); D000516:alpha-Amylases