Protein having lactase activity, gene encoding the protein, recombinant vector containing the gene, transformant, production method and use thereof

摘要

To provide a protein having a novel lactase activity which is stable at pH 1-2 and has high activity at pH 4-5. The present invention provides a protein having lactase activity that has the highest activity around pH 3.0 to 4.0 and a stable pH range of pH 1.5 to 7.0. The protein according to the present invention is stable in the stomach on an empty stomach and exhibits high activity in the stomach after a meal, so that an enzyme preparation, a pharmaceutical composition, or a quasi-drug containing this as an active ingredient The composition or the food composition can be ingested before a meal, and can also realize a very high lactose decomposition action even after a meal.