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Acylation is a common method for chemical modification of proteins, which can effectively improve the functional properties of proteins and has been widely used in food processing in recent years. The effect of acylation on protein modification is related to the degree of modification, and low degree of acylation modification can significantly improve the solubility, thermal stability, foaming and emulsifying properties, gelation properties, film-forming properties and nutritional quality of proteins. This paper reviews the effect of acylation modification on protein structure, physicochemical properties, and functional properties, as well as the application of acylated proteins in food and other fields. Hopefully, this review will provide a theoretical reference for protein modification research.

Firstly, We used error-prone PCR to induce mutations on Armillariella tabescens MAN47 beta-mannanase gene, Secondly, we cloned the mutated fragments into secreted expression vector pYCalpha, Then the recombinant plasmids were transformed into Saccharomyces cerevisiae BJ5465 after amplified and extracted in DH5alpha cells. Through three cycles of error-prone PCR we built a mutant database, Then we screened one optimum (named M262) from about 104 mutants. The evoluted MAN47 beta-mannanase displayed both higher thermal stability and activity than wide type. The evoluted enzyme M262 retained high activity after treatment at 80 degrees C for 30 min, whereas, the wild type nearly lost activity under this condition. Meanwhile, the activity of M262 can reach to 25 U/mL, which is 4.3 times as wide type under optimum temperature. In addition, pH stability and pH range of evoluted enzyme M262 were both improved compared with wild-type enzyme. The optimum pH was estimated to be similar to that of wild-type enzyme. The sequence comparison illustrated that there were three nucleotide substitutions (T343A/C827T/T1139C) which carried corresponding amino acid changes (Ser115Thr/Thr276Met/Val380Ala). According to homologous modeling by SWISS-MODEL Repository, three mutated amino acids located at the sixth amino acid of the fourth beta-sheet, the first amino acid of the sixth alpha-helix, the turn between the tenth and eleventh beta-sheet, respectively.