ABSTRACT
A number of biochemical systems are photoactive in the visible region through electronic transitions. The rhodopsin protein in vertebrate eyes is a representative case of such photoabsorptions. As for emissions, the green fluorescent protein (GFP)1 and related derivatives are useful marker labels in the field of biotechnology. The central region in photoactive proteins is known as the chromophore, and it consists of the crucial pigment part and some neighboring residues that should provide the electrostatic or hydrogen-bonding interactions with the pigment. Surrounding residues also put some electrostatic potentials on the chromophore system. These environmental
4.1 Introduction .................................................................................................... 63 4.2 Methods of Calculation...................................................................................65
