Method for modifying a protein, food preparation of enzyme to modify a protein, and method for establishing an optimum ratio of protein glutaminase for transglutaminase

摘要

Provided are: a method of denaturing a protein by treating the protein with both of protein glutaminase and transglutaminase; a food containing a protein having been denatured with these enzymes; an enzyme preparation for denaturing a protein which comprises these enzymes; and a method of establishing an optimum quantitative ratio of protein glutaminase to transglutaminase both of which are to be added to a protein. A protein is denatured by adding protein glutaminase and transglutaminase to the protein substantially at the same timing, or adding protein glutaminase to the protein before the transglutaminase acts on the protein, or controlling the quantitative ratio of protein glutaminase to transglutaminase, by which a protein is treated, to a definite level. The optimum quantitative ratio of protein glutaminase to transglutaminase, both of which are to be added to a protein, is determined based on the NMR signal intensity of the protein labeled with isotope-labeled ammonium or the like.