Abstract: A novel luciferase that is distinct from conventional luciferase has been desired. A luciferase mutant comprising an amino acid sequence in which glutamic acid at position 4, arginine at position 11, leucine at position 18 and valine at position 27 are substituted with other amino acids, in the amino acid sequence of SEQ ID NO: 2.

Abstract: A novel luciferase that is distinct from conventional luciferase has been desired. A luciferase mutant comprising an amino acid sequence in which glutamic acid at position 4, arginine at position 11, leucine at position 18 and valine at position 27 are substituted with other amino acids, in the amino acid sequence of SEQ ID NO: 2.

Abstract: A novel luciferase that is distinct from conventional luciferase has been desired. A luciferase mutant comprising an amino acid sequence in which glutamic acid at position 4, arginine at position 11, leucine at position 18 and valine at position 27 are substituted with other amino acids, in the amino acid sequence of SEQ ID NO: 2.

Abstract: A novel luciferase that is distinct from conventional luciferase has been desired. A luciferase mutant comprising an amino acid sequence in which glutamic acid at position 4, arginine at position 11, leucine at position 18 and valine at position 27 are substituted with other amino acids, in the amino acid sequence of SEQ ID NO: 2.

Abstract: A novel luciferase that is distinct from conventional luciferase has been desired. A luciferase mutant comprising an amino acid sequence in which glutamic acid at position 4, arginine at position 11, leucine at position 18 and valine at position 27 are substituted with other amino acids, in the amino acid sequence of SEQ ID NO: 2.

Abstract: Coelenterazine analogs having luminescence properties different from those of known coelenterazine analogs are desired for various luciferases. The invention provides compounds represented by general formula (1) below.

Abstract: Coelenterazine analogs having luminescence properties different from those of known coelenterazine analogs are desired for various luciferases. The invention provides compounds represented by general formula (1) below.

Abstract: Described include (1) a substituted pyrazine compound of general formula (VIII): and (2) a process for producing the substituted pyrazine compound of general formula (VIII), where R1 is hydrogen, a halogen, a substituted or unsubstituted hydrocarbon group, or a substituted or unsubstituted heterocyclic group, and R4 is a protecting group. The process comprises (1) the step of reacting 2-amino-3,5-dibromo-6-chloropyrazine with R1MgX and ZnCl2 in the presence of a palladium catalyst to produce a compound of general formula (V); (2) the step of reacting the compound of general formula (V) with a compound of general formula (VI) to produce a compound of general formula (VII); and (3) the step of reacting the compound of formula (VII) with tributyl(vinyl)tin in the presence or a palladium catalyst to given the compound of general formula (VIII).

Abstract: Calcium-binding photoproteins showing the luminescence pattern with a slow decay of are desired. The invention provides a mutant apoprotein comprising an amino acid sequence wherein the 23rd to 34th amino acids in the amino acid sequence of SEQ ID NO: 2 are substituted with an amino acid represented by formula I below: Xaa23-Xaa24-Xaa25-Xaa26-Xaa27-Xaa28-Xaa29-Xaa30-Xaa31-Xaa32-Xaa33-Xaa 34; having a function to bind to the peroxide of coelenterazine or the peroxide of a coelenterazine analog to form a photoprotein capable of emitting light under the action of calcium ions; and, having a half decay time of the luminescence emitted by binding of the photoprotein to calcium ions being not less than 2 seconds.

Abstract: A novel luciferase that is distinct from conventional luciferase has been desired. A luciferase mutant comprising an amino acid sequence in which glutamic acid at position 4, arginine at position 11, leucine at position 18 and valine at position 27 are substituted with other amino acids, in the amino acid sequence of SEQ ID NO: 2.

Abstract: A simple process for producing ?-coelenterazine compounds has been desired. Described is a process for producing a ?-coelenterazine compound represented by general formula (II) comprising (1) the step of reacting a compound of general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound of general formula (X) which is the compound of general formula (IX) wherein the amino is protected with R5, and then deprotecting R4 and, if any, R5 to give a ?-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound of general formula (XIV) with a compound represented by general formula (XV) to give the compound of general formula (II).

Abstract: Calcium-binding photoproteins showing the luminescence pattern with a slow decay of are desired. The invention provides a mutant apoprotein comprising an amino acid sequence wherein the 23rd to 34th amino acids in the amino acid sequence of SEQ ID NO: 2 are substituted with an amino acid represented by formula I below: Xaa23-Xaa24-Xaa25-Xaa26-Xaa27-Xaa28-Xaa29-Xaa30-Xaa31-Xaa32-Xaa33-Xaa 34; having a function to bind to the peroxide of coelenterazine or the peroxide of a coelenterazine analogue to form a photoprotein capable of emitting light under the action of calcium ions; and, having a half decay time of the luminescence emitted by binding of the photoprotein to calcium ions being not less than 2 seconds.

Abstract: A simple process for producing ?-coelenterazine compounds has been desired. The invention provides a process for producing a ?-coelenterazine compound represented by general formula (II) which comprises (1) the step of reacting a compound represented by general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound represented by general formula (X) which is the compound represented by general formula (IX) wherein the amino is protected with R5, and then deprotecting R4 and, if any, R5 to give a ?-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound represented by general formula (XIV) with a compound represented by general formula (XV) to give the compound represented by general formula (II).

Abstract: A simple process for producing v-coelenterazine compounds has been desired. Described is a process for producing a v-coelenterazine compound represented by general formula (II) comprising (1) the step of reacting a compound of general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound of general formula (X) which is the compound of general formula (IX) wherein the amino is protected with R5, and then deprotecting R4 and, if any, R5 to give a v-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound of general formula (XIV) with a compound represented by general formula (XV) to give the compound of general formula (II).

Abstract: Coelenterazine analogs having luminescence properties different from those of known coelenterazine analogs are desired for various luciferases. The invention provides compounds represented by general formula (1) below.

Abstract: Calcium-binding photoproteins showing the luminescence pattern with a slow decay of are desired. The invention provides a mutant apoprotein comprising an amino acid sequence wherein the 23rd to 34th amino acids in the amino acid sequence of SEQ ID NO: 2 are substituted with an amino acid represented by formula I below: Xaa23-Xaa24-Xaa25-Xaa26-Xaa27-Xaa28-Xaa29-Xaa30-Xaa31-Xaa32-Xaa33-Xaa 34; having a function to bind to the peroxide of coelenterazine or the peroxide of a coelenterazine analogue to form a photoprotein capable of emitting light under the action of calcium ions; and, having a half decay time of the luminescence emitted by binding of the photoprotein to calcium ions being not less than 2 seconds.

Abstract: A simple process for producing v-coelenterazine compounds has been desired. Described is a process for producing a v-coelenterazine compound represented by general formula (II) comprising (1) the step of reacting a compound of general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound of general formula (X) which is the compound of general formula (IX) wherein the amino is protected with R5, and then deprotecting R4 and, if any, R5 to give a v-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound of general formula (XIV) with a compound represented by general formula (XV) to give the compound of general formula (II).

Abstract: A simple process for producing v-coelenterazine compounds has been desired. Described is a process for producing a v-coelenterazine compound represented by general formula (II) comprising (1) the step of reacting a compound of general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound of general formula (X) which is the compound of general formula (IX) wherein the amino is protected with R5, and then deprotecting R4 and, if any, R5 to give a v-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound of general formula (XIV) with a compound represented by general formula (XV) to give the compound of general formula (II).

Abstract: Calcium-binding photoproteins showing the luminescence pattern with a slow decay of are desired. The invention provides a mutant apoprotein comprising an amino acid sequence wherein the 23rd to 34th amino acids in the amino acid sequence of SEQ ID NO: 2 are substituted with an amino acid represented by formula I below: Xaa23-Xaa24-Xaa25-Xaa26-Xaa27-Xaa28-Xaa29-Xaa30-Xaa31-Xaa32-Xaa33-Xaa 34; having a function to bind to the peroxide of coelenterazine or the peroxide of a coelenterazine analogue to form a photoprotein capable of emitting light under the action of calcium ions; and, having a half decay time of the luminescence emitted by binding of the photoprotein to calcium ions being not less than 2 seconds.

Abstract: A simple process for producing v-coelenterazine compounds has been desired. Described is a process for producing a v-coelenterazine compound represented by general formula (II) comprising (1) the step of reacting a compound of general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound of general formula (X) which is the compound of general formula (IX) wherein the amino is protected with R5, and then deprotecting R4 and, if any, R5 to give a v-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound of general formula (XIV) with a compound represented by general formula (XV) to give the compound of general formula (II).