[Enzymatic and conformational stability of polymeric complexes of alpha-amylase].
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.
Iurchenko
V S
VS
Illarionova
N G
NG
Denisov
I G
IG
Ponomareva
R B
RB
Rozhetskaia
K M
KM
D001412:Bacillus subtilis / Q000201:enzymology; D002942:Circular Dichroism; D004795:Enzyme Stability; D011109:Polymethacrylic Acids; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D000516:alpha-Amylases
D011109:Polymethacrylic Acids; D000516:alpha-Amylases
Fermentativnaia i konformatsionnaia stabil'nost' polimernykh kompleksov alpha-amilazy.