Patent ID: 6376257
Filing Date: 2002-04-23
Classification: G01N

Abstract:
A method of monitoring a change in the amount of calmodulin associated with metal ion in a cell, said method comprising:exposing a cell to a first wavelength, wherein the cell contains metal ions and a green fluorescent protein complex comprising: a first green fluorescent protein which is excited at the first wavelength and which emits fluorescence at a second wavelength; a calmodulin-binding peptide capable of reversibly binding to calmodulin associated with metal ion, the calmodulin-binding peptide having amino terminal and carboxy terminal ends, one of the amino terminal and carboxy terminal ends of the calmodulin-binding peptide being covalently attached to the first green fluorescent protein; and a second green fluorescent protein which is excited at the second wavelength and which emits fluorescence at a third wavelength, the other of the amino terminal and carboxy terminal ends of the calmodulin-binding peptide being covalently attached to the second green fluorescent protein; measuring a base amount of fluorescence emission at the third wavelength when the cell is exposed to the first wavelength; measuring a second amount of fluorescence emission at the third wavelength when the cell is exposed to the first wavelength, said measuring the second amount of fluorescence emission being carried out subsequent to said measuring the base amount of fluorescence emission; and comparing the second amount of fluorescence emission to the base amount of fluorescence emission, wherein a lesser second amount of fluorescence emission indicates an increase in the amount of calmodulin associated with metal ion in the cell and a greater second amount of fluorescence emission indicates a decrease in the amount of calmodulin associated with metal ion in the cell.