Patent ID: 7329735
Filing Date: 2008-02-12
Classification: C07K,C12Q,G01N

Abstract:
1. An isolated fluorescent polypeptide variant of a wild type Discoma red fluorescent protein (DsRed), which wild type protein comprises the amino acid sequence of SEQ ID NO: 1, the polypeptide variant comprising at least a first and a second amino acid alteration of SEQ ID NO: 1, wherein the first amino acid alteration comprises a substitution at an amino acid residue selected from the group consisting of 66 and 147 of SEQ ID NO:1, and results in increased efficiency of maturation compared to the efficiency of maturation of wild type DsRed of SEQ ID NO:1, and wherein the second amino acid alteration comprises an alteration at the AB interface, the AC interface, or at the AB and AC interfaces of the wild type DsRed protein of SEQ ID NO: 1 which results in a reduced propensity to form tetramers compared to the propensity to form tetramers of wild type SEQ ID NO: 1, the second amino acid alteration comprising a substitution at an amino acid position selected from the group consisting of 125, 127, 153, 162, 164, 174, 180, 192, 194, 222, 223, 224, and 225 of the amino acid sequence of SEQ ID NO:1, wherein said fluorescent polypeptide variant has at least 90% amino acid sequence identity to SEQ ID NO:1.