Calcium sensor protein using red fluorescent protein

摘要

PROBLEM TO BE SOLVED: To provide a red fluorescent calcium sensor used for detecting variation of calcium in the organism (extracellular and intracellular) and measuring concentration of calcium and having more excellent reactivity than the conventional one.SOLUTION: The red fluorescent calcium sensor protein is a modified protein obtained by modifying the structure of red fluorescent protein mApple in the vicinity of a hot spot amino acid residue exerting influence on fluorescent properties, linking thereto functional molecules functioning so as to change fluorescent properties, and adding linker peptide made of specified 15 amino acid and specified peptide made of 22 amino acid to the C terminal region thereof. Such a protein exhibits high fluorescence reactivity and exhibits no localization into the nuclei.