title: [Enzymatic and conformational stability of polymeric complexes of alpha-amylase].
abstract: The enzymatic and conformational stability of Bacillus subtilis alpha-amylase and its polymeric complexes in acid media and subsequent renaturation in weakly alkaline media were investigated. The following parameters of alpha-amylase secondary structure were determined from circular dichroism spectra: helical units -25%, beta-structures -9%; beta-turns -13%; disordered conformations -53%. After complexation with polymethacrylic acid (PMAA) the alpha-amylase secondary structure did not change, and the tertiary structure underwent only small local changes. Complexation of alpha-amylase with linear and cross-linked PMAA led to an increase in both enzymatic and conformational stabilities in acid media. Purification of alpha-amylase using a biosorbent resulted in higher acid resistance of the free enzyme and of that in the complex with PMAA. Moreover, the degree of reversibility of the acid inactivation also increased.
authors.forename: V S
authors.initials: VS
authors.lastname: Iurchenko
authors.forename: N G
authors.initials: NG
authors.lastname: Illarionova
authors.forename: I G
authors.initials: IG
authors.lastname: Denisov
authors.forename: R B
authors.initials: RB
authors.lastname: Ponomareva
authors.forename: K M
authors.initials: KM
authors.lastname: Rozhetskaia
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D002942:Circular Dichroism; D004795:Enzyme Stability; D011109:Polymethacrylic Acids; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D000516:alpha-Amylases
chemical_list: D011109:Polymethacrylic Acids; D000516:alpha-Amylases
vernacular_title: Fermentativnaia i konformatsionnaia stabil'nost' polimernykh kompleksov alpha-amilazy.