CITRATE SPECIFIC FLUORESCENT SENSOR PROTEIN, AND METHOD OF MEASURING CITRATE CONCENTRATION USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an agent for measuring a citrate concentration capable of measuring continuously or chronologically, and capable of measuring the citrate concentration inside specific cells or intracellular organella in vivo nondestructively.SOLUTION: A citrate specific fluorescent sensor protein comprises, from its amino terminal side to its carboxy terminal side, an amino acid sequence of a first citrate binding polypeptide, an amino acid sequence of a fluorescent protein, and an amino acid sequence of a second citrate binding polypeptide. The first citrate binding polypeptide and the second citrate binding polypeptide are two polypeptides obtained by cleavage of peptide bond of periplasmic space domain of sensor histidine kinase CitA that comprises a specific amino acid sequence. The fluorescent protein is a circularly permuted green fluorescent protein. An agent for measuring citrate concentration comprises the sensor protein and a transformant expressing the same.