[Enzymatic and conformational stability of polymeric complexes of alpha-amylase]

Autor: V S, Iurchenko, N G, Illarionova, I G, Denisov, R B, Ponomareva, K M, Rozhetskaia
Rok vydání: 1989
Předmět:
Zdroj: Prikladnaia biokhimiia i mikrobiologiia. 25(1)
ISSN: 0555-1099
Popis: 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.
Databáze: OpenAIRE