CRYSTALLIZATION AND CRYSTALLOGRAPHIC INVESTIGATIONS OF COD ALCOHOL-DEHYDROGENASE CLASS-I AND CLASS-III ENZYMES

Cod liver alcohol dehydrogenase of class-hybrid properties has been cr ystallized as an NAD(+)-pyrazole complex in the monoclinic space group P2(l) with cell dimensions a = 103.3 Angstrom, b = 47.4 Angstrom, c = 80.7 Angstrom,beta = 104.6 degrees, and with one dimer in the asymmet ric unit. The position of the dimer molecule in the crystal was determ ined by molecular replacement methods at 3.0 A resolution. The success ful search model was the poly-alanine structure of the horse enzyme. S ide chains were then replaced according to the amino acid sequence of the cod enzyme, and the structure has been refined at 2.8 A to an R-fa ctor of 0.26. Cod liver class III alcohol dehydrogenase crystallizes i n the monoclinic space group C2 with cell dimensions a = 127.5 Angstro m, b = 76.6 Angstrom, c = 93.4 Angstrom, P = 99.4 degrees and with pro bably one dimer in the asymmetric unit.