Ultramarine fluorescent protein

Abstract

The present invention provides an artificial mutant of GFP having a novel emission peak, i.e., a fluorescent protein having an emission peak at 424 nm comprising an amino acid sequence represented by SEQ ID NO: 1, in which each of the amino acid residues at the 66th position and the 175th position is replaced and at least one of the amino acid residues at the 72nd position and the 206th position is further replaced, or a fluorescent protein having an emission peak at 424 nm and a pH-independent fluorescence intensity, in which each of the amino acid residues at the 65th, 145th, 148th, 46th and/or 203rd positions is further substituted. The fluorescent protein of the invention emits fluorescence having an emission peak at 424 nm and can be visually distinguished by its ultramarine color from other fluorescent proteins. The fluorescent protein has a pH-independent fluorescence intensity which is not affected by pH changes.

Dependencies are inferred from the claim text.