Enzyme engineering strategies for catalytic activity in wide pH range

Enzymes play a critical role in lowering the activation energy of the reaction to convert a substrate into a product. But, conditions such as extreme pH range affect their performance due to the disruption of their native three-dimensional structure. However, enzymes from extremophiles have made adjustment in the amino acid according to their conditions such that the interaction can be maintained at extreme conditions. In order to make enzymes from mesophilic organism, computational and directed evolutionary approaches are in demand. These approaches have proven their potential in improving the pH stability of alpha-amylase and xylanase. In silico comparison of enzymes from alkaline and acidic microbes have shown differences in the amino acid composition. Apart from these, different physical forces such as covalent bonds, noncovalent hydrophobic, electrostatic, Van der Waals interactions, and hydrogen bonds play an important role in maintaining the native conformation of enzymes in extreme pH condition. The structural and the sequence information form the basis of computational approaches, that is, rational and de novo designing for the improvement of enzyme performance.