Crystallization of a fluorescent derivative of glyceraldehyde-3-phosphate dehydrogenase.

By phosphorus analysis of the fluorescent derivative produced by ultraviolet irradiation of carboxymethylated glyceraldehyde-3-phosphate dehydrogenase in the presence of NAD at saturation levels, it has been shown that the photochemical reaction leading to the formation of the new fluorophore is also a 'half-of-the-sites' reaction. Both the carboxymethylated enzyme and the irradiated enzyme carrying the new fluorophore have been crystallized.