Rational protein design for enhancing thermal stability of industrial enzymes

Enzymes possessing many excellent properties such as high selectivity, consuming less energy, and producing less side products or waste have been widely applied as biocatalysts in pharmaceutical production and many industries such as biofuel, biomaterials, biosensor, food, and environmental treatment. Although enzymes have shown its potential as biocatalysts for many industrial applications, natural enzymes were not originated for manufacturing process which requires harsh reaction conditions such as high temperature, alkaline pH, and organics solvents. It was reported that reduction of final conversion of several enzymatic reactions was declined at high temperature. Protein engineering to improve the enzymes’ thermostability is crucial to extend the use of the industrial enzymes and maximize effectiveness of the enzyme-based procesess. Various industrial enzymes with improved thermostability were produced through rational protein engineering using different strategies. This review is not aimed to cover all successful rational protein engineering studies. The review focuses on some effective strategies which have widely used to increase the thermostability of several industrial enzymes through introduction of disulfide bonds and introduction of proline.