Patent ID: 8765921

Claim:
A method for producing a calcium-binding photoprotein, which comprises contacting the compound represented by the general formula (1) below: wherein: R 1 is (a) hydrogen, (b) hydroxy, (c) an alkyl having 1 to 4 carbon atoms which may optionally be substituted with an alicyclic group, or (d) trifluoromethyl; R 2 is (a) hydrogen, (b) hydroxy, (c) a halogen, (d) an alkyl having 1 to 4 carbon atoms which may optionally be substituted with an alicyclic group, (e) trifluoromethyl or (f) an alkoxyl; R 3 is (a) hydrogen, (b) an alkyl having 1 to 4 carbon atoms which may optionally be substituted with an alicyclic group, or (c) an alkoxyl; R 4 is a substituted or unsubstituted benzyl; R 5 is (a) hydrogen or (b) a substituted or unsubstituted alkyl; X 1 is (a) hydrogen or (b) hydroxy; and X 2 is (a) hydrogen or (b) hydroxy; with the proviso that when R 2 and R 3 are hydrogen, R 1 is (a) an alkyl having 1 to 4 carbon atoms which may optionally be substituted with an alicyclic group, or (b) trifluoromethyl, when R 1 and R 3 are hydrogen, R 2 is (a) hydroxy, (b) an alkyl having 1 to 4 carbon atoms which may optionally be substituted with an alicyclic group, (c) trifluoromethyl, or (d) an alkoxyl, and, when R 1 and R 2 are hydrogen, R 3 is (a) an alkyl having 1 to 4 carbon atoms which may optionally be substituted with an alicyclic group, or (b) an alkoxyl, with an apoprotein of the calcium-binding photoprotein to obtain the calcium-binding photoprotein.