The invention discloses a method of reducing
disulfide bond in photo-excitation
protein to obtain free sulfydryl. The method comprises the following steps: (1) preparing the
protein solution, wherein the concentration of the
protein is smaller than 1mM, the pH is 7-8, and the temperature of the
protein solution is 10-400 DEG C; and (2) conducting
ultraviolet irradiation to the
protein solution for 10-1000 minutes to obtain free sulfydryl-containing protein, wherein the
irradiation intensity is smaller than 30W / m<2> and the
irradiation time is 10-1000min. The method is simple to operate, efficient and fast, and has strong specificity and least damage to the structure of the protein. Therefore, the method of obtaining the free sulfydryl through photo-exciting the protein can be used for
high coverage rate of the protein in an interface, and is orderly in orientation and constant in specificity; and the technology has significant application prospects in the fields of biosensors, biomaterials, bio-energy sources and the like, thereby bringing tremendous
economic benefits and
social benefits for the development of industries of medical, chemical and the like.