Oplophorus-derived luciferases, novel coelenterazine substrates, and methods of use

1. An isolated polynucleotide encoding a polypeptide having at least 80% sequence identity to SEQ ID NO: 1 and comprising one or more amino acid substitutions relative to SEQ ID NO: 3, wherein at least one amino acid substitution is at a position corresponding to position 27 of SEQ ID NO: 1, and wherein the polypeptide has enhanced luminescence relative to SEQ ID NO: 3.

2. The polynucleotide of claim 1 , wherein the at least one amino acid substitution corresponds to leucine, valine, alanine, aspartate, glycine or isoleucine at position 27 of SEQ ID NO: 1.

3. The polynucleotide of claim 1 , wherein the polypeptide comprises an amino acid substitution at one or more positions corresponding to positions 43, 38, 109, 15, 19, 21, 22, 36, 40, 56, 58, 70, 93, 95, 102, 110, 112, 119, 127, 128, 149, 152, 155, 158, 159, 1, 6, 10, 14, 16, 24, 25, 31, 32, 39, 42, 46, 47, 48, 49, 50, 55, 59, 60, 66, 67, 69, 71, 74, 86, 87, 94, 96, 97, 98, 100, 106, 111, 113, 117, 125, 126, 129, 130, 136, 142, 145, 146, 147, 148, 150, 154, 163, and 168 of SEQ ID NO: 1.

4. The polynucleotide of claim 3 , wherein the polypeptide further comprises an amino acid substitution at positions 54 and 90 corresponding to SEQ ID NO: 1, wherein the amino acid at position 54 is isoleucine or alanine and the amino acid at position 90 is valine.

5. The polynucleotide of claim 3 , wherein the polypeptide comprises SEQ ID NO: 15.

6. The polynucleotide of claim 3 , wherein the polypeptide further comprises an amino acid substitution at positions 18, 68, 72 and 75 corresponding to SEQ ID NO: 1.

7. The polynucleotide of claim 6 , wherein the amino acid at position 18 is leucine, at position 68 is tyrosine, at position 72 is glutamine and at position 75 is lysine.

8. The polynucleotide of claim 6 , wherein the polypeptide further comprises an amino acid substitution at positions 33, 27, 43 and 68 corresponding to SEQ ID NO: 1.

9. The polynucleotide of claim 8 , wherein the amino acid at position 33 is asparagine, at position 27 is valine, at position 43 is arginine and at position 68 is aspartate.

10. The polynucleotide of claim 8 , wherein the polypeptide further comprises at least one amino acid substitution at a position corresponding to positions 11, 44, 115, 124, or 138 of SEQ ID NO: 1.

11. The polynucleotide of claim 10 , wherein the at least one amino acid substitution corresponds to at least one of glutamine at position 11, valine at position 44, proline at position 115, glutamine at position 124, or tyrosine at position 138 corresponding to SEQ ID NO: 1.

12. The polynucleotide of claim 3 , wherein the polypeptide further comprises an amino acid substitution selected from the following group: the amino acid at position 4 is alanine, the amino acid at position 33 is lysine or alanine, the amino acid at position 43 is lysine, the amino acid at position 75 is methionine or the amino acid at position 166 is asparagine or phenylalanine, wherein the amino acid positions correspond to SEQ ID NO: 1.

13. The polynucleotide of claim 1 , wherein the sequence has been codon-optimized for a host cell.

14. The polynucleotide of claim 1 , wherein the polynucleotide further encodes a polypeptide of interest linked to the polypeptide, the polypeptide of interest and the polypeptide capable of being expressed as a fusion protein.

15. The polynucleotide of claim 1 , wherein the polypeptide is a soluble monomer.

16. A vector comprising the polynucleotide of claim 1 .

17. The vector of claim 16 , wherein the polynucleotide is operably linked to a promoter.

18. A non-human cell comprising the polynucleotide of claim 1 .