Abstract: The present invention provides a method of designing an optimized gene which comprises altering a nucleotide sequence of a target protein gene, so that only preferential codons with high frequency of use in human cells are selected and a GC content of not less than 60% is achieved. A gene design method which involves the feature “only preferential codons with high frequency of use are selected and a GC content of not less than 60% is achieved” can be established as a general rule for preparing proteins with high expression level, in order to obtain chemically synthesized genes for proteins capable of high-level expression in eukaryotes.

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: Luciferases which are different from those known heretofore have been desired. A luciferase mutant comprising an amino acid sequence in which at least one amino acid selected from the group consisting of valine at the position of 44, alanine at the position of 54 and tyrosine at the position of 138 is substituted with other amino acid(s) in the amino acid sequence of SEQ ID NO: 2.

Abstract: Luciferases which are different from those known heretofore have been desired. A luciferase mutant comprising an amino acid sequence in which at least one amino acid selected from the group consisting of valine at the position of 44, alanine at the position of 54 and tyrosine at the position of 138 is substituted with other amino acid(s) in the amino acid sequence of SEQ ID NO: 2.

Abstract: Luciferases which are different from those known heretofore have been desired. A luciferase mutant comprising an amino acid sequence in which at least one amino acid selected from the group consisting of valine at the position of 44, alanine at the position of 54 and tyrosine at the position of 138 is substituted with other amino acid(s) in the amino acid sequence of SEQ ID NO: 2.

Abstract: The screening method of the present invention is useful for screening drugs such as insulin secretagogues having an insulin secretagogue activity with minimized side effects (hypoglycemia induction, etc.). The transformant in which a polynucleotide encoding the fusion protein used for the screening method is introduced, the screening kit comprising the transformant, etc. are also useful for screening excellent drugs.

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: The present invention provides a method of designing an optimized gene which comprises altering a nucleotide sequence of a target protein gene, so that only preferential codons with high frequency of use in human cells are selected and a GC content of not less than 60% is achieved. A gene design method which involves the feature “only preferential codons with high frequency of use are selected and a GC content of not less than 60% is achieved” can be established as a general rule for preparing proteins with high expression level, in order to obtain chemically synthesized genes for proteins capable of high-level expression in eukaryotes.

Abstract: The present invention provides a method of designing an optimized gene which comprises altering a nucleotide sequence of a target protein gene, so that only preferential codons with high frequency of use in human cells are selected and a GC content of not less than 60% is achieved. A gene design method which involves the feature “only preferential codons with high frequency of use are selected and a GC content of not less than 60% is achieved” can be established as a general rule for preparing proteins with high expression level, in order to obtain chemically synthesized genes for proteins capable of high-level expression in eukaryotes.

Abstract: A novel luciferase that distinct from conventional luciferase has been desired. A luciferase mutant comprising the amino acid sequence of SEQ ID NO: 2 substituted at tyrosine at the position of 138, and at least 3 positions selected from the group consisting of isoleucine at the position of 90, proline at the position of 115, glutamine at the position of 124, and asparagine at the position of 166.

Abstract: The invention provides calcium-binding photoproteins which can detect light emission with a higher sensitivity. The proteins of the invention comprising the amino acid sequence of SEQ ID NO: 2 can be used for the detection and measurement of calcium ions. The proteins of the invention are useful as reporter proteins, luminescent markers, etc. The polynucleotides of the invention are useful as reporter genes, etc.

Abstract: Luciferases which are different from those known heretofore have been desired. A luciferase mutant comprising an amino acid sequence in which at least one amino acid selected from the group consisting of valine at the position of 44, alanine at the position of 54 and tyrosine at the position of 138 is substituted with other amino acid(s) in the amino acid sequence of SEQ ID NO: 2.

Abstract: There has been a demand for a codon-optimized gene for the mutated catalytic domain of Oplophorus luciferase, which is capable of efficiently expressing a protein both in a cultured animal cell and Escherichia coli. There has also been a demand for a substrate coelenterazine analog showing a higher activity than that of native 19 kDa protein. The invention provides a polynucleotide comprising a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 2. According to the invention, bis-coelenterazine is used as a substrate coelenterazine analog suitable for the photoprotein encoded by the polynucleotide comprising the polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 2.

Abstract: The present invention provides a method of designing an optimized gene which comprises altering a nucleotide sequence of a target protein gene, so that only preferential codons with high frequency of use in human cells are selected and a GC content of not less than 60% is achieved. A gene design method which involves the feature “only preferential codons with high frequency of use are selected and a GC content of not less than 60% is achieved” can be established as a general rule for preparing proteins with high expression level, in order to obtain chemically synthesized genes for proteins capable of high-level expression in eukaryotes.

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: Luciferases which are different from those known heretofore have been desired. A luciferase mutant comprising an amino acid sequence in which at least one amino acid selected from the group consisting of valine at the position of 44, alanine at the position of 54 and tyrosine at the position of 138 is substituted with other amino acid(s) in the amino acid sequence of SEQ ID NO: 2.

Abstract: The present invention provides a method of designing an optimized gene which comprises altering a nucleotide sequence of a target protein gene, so that only preferential codons with high frequency of use in human cells are selected and a GC content of not less than 60% is achieved. A gene design method which involves the feature “only preferential codons with high frequency of use are selected and a GC content of not less than 60% is achieved” can be established as a general rule for preparing proteins with high expression level, in order to obtain chemically synthesized genes for proteins capable of high-level expression in eukaryotes.

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: The screening method of the present invention is useful for screening drugs such as insulin secretagogues having an insulin secretagogue activity with minimized side effects (hypoglycemia induction, etc.). The transformant in which a polynucleotide encoding the fusion protein used for the screening method is introduced, the screening kit comprising the transformant, etc. are also useful for screening excellent drugs.