Allosteric mechanism of synergistic effect in α- and β-amylase mixtures.

Alpha-amylase and beta-amylase coexist as mixtures in industrial production, and the two amylases have active synergistic effects when they approach each other. These effects are due to enhanced enzyme binding affinity for the substrate and the rate of particle hydrolysis. Here, we report the allosteric mechanism of this synergistic effect in α- and β-amylase mixtures.

Allosteric regulation of α-amylase induced by ligands binding.

The conformational changes in α-amylase induced by different ligands, including metal ions, substrates, and aromatic compounds in liquor production, were systematically studied using spectroscopy. Fluorescence acrylamide quenching analysis showed that the interaction with active metal cations (K, Na, and Ca) led to higher exposure of the active sites in α-amylase. In contrast, interactions with substrates (soluble starch, amylose, amylopectin, wheat starch, and dextrin) reduced the degree of exposure of active sites, and the conformation of the enzyme became more rigid and compact.