Patent ID: 8822170

Claim:
A thermostable beetle luciferase variant of Photuris pennsylvanica of SEQ ID NO: 37 comprising amino acid substitutions at amino acids corresponding to residues 91, 220, 353, and 354 of SEQ ID NO:37 and a substitution of residue 2 with A, a substitution of residue 183 with Y, a substitution of residue 221 with A, a substitution of residue 249 with M, a substitution of residue 262 with V, a substitution of residue 294 with L, a substitution of residue 386 with P, a substitution of residue 399 with G, a substitution of residue 542 with T, a substitution of residue 543 with N, a substitution of residue 544 with G, and a deletion of residue 545 of SEQ ID NO:37, wherein said luciferase variant retains at least 50% activity in aqueous solution for at least 2 hours at a temperature of 50° C. and has up to 42 amino acids modified from SEQ ID NO:37.