Chemical Function of Substituted Amino Acids in Glyceraldehyde-3-PhosphateDehydrogenase

摘要

An investigation of the amino acids responsible for the thermostability of the T.aquaticus glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was initiated. The gene encoding this enzyme was isolated from a genomic library and sequenced. The gene encoded a functional GAPDH by virtue of its ability to rescue a mutant bacterial strain whose own GAPDH gene was deleted. The heat-stability of the isolated enzyme is impressive, i.e., it retains 100% of its activity after 2 hours at 90 C while requiring 100 C to lose 50% of its activity. Defining the conditions for crystallization as well as the physicochemical properties of the purified GAPDH are currently ongoing.