Lipase mutant and application thereof in purification of natural vitamin E

The invention discloses a lipase mutant and application thereof in purification of natural vitamin E. The invention relates to the technical field of gene engineering and protein modification, in particular to a lipase mutant. According to the invention, on the basis of wild type lipase TLS, a lipase mutant which respectively contains T136W single-point mutation, G113V/T136W two-point mutation and G113V/T136W/I277P three-point mutation is provided. Compared with a wild type, the lipase mutant has the advantage that the tolerance of the lipase mutant to an acidic condition is obviously enhanced. After the mutant is treated for 15 minutes under the condition of pH 3.0, the enzyme activity residual rate of the mutant can still reach 30.20%-44.33% and is far higher than that of a wild type. The lipase mutant can remarkably promote methyl esterification of free fatty acid, and the conversion rate is up to 72.40%-89.23%; wherein the lipase mutant containing G113V/T136W/I277P three-point mutation has the highest met