POLYSULFIDE REDUCTASE AND FORMATE DEHYDROGENASE FROM WOLINELLA-SUCCINOGENES CONTAIN MOLYBDOPTERIN GUANINE DINUCLEOTIDE

Pterin derivatives were extracted from formate dehydrogenase and from polysulfide reductase of Wolinella succinogenes and converted to 6-car boxypterin. The amounts of 6-carboxypterin were consisted with the mol ybdenum content of the enzymes. The bis(carboxamidomethyl) derivatives of the cofactors showed absorption spectra that were identical with t hat of the corresponding molybdopterin guanine dinucleotide derivative (cam MGD). After hydrolysis of the derivatives with nucleotide pyroph osphatase in the presence of alkaline phosphatase, guanosine was forme d together with a compound showing the properties of dephospho-bis(car boxamidomethyl) molybdopterin. It is conluded that both formate dehydr ogenase and polysulfide reductase of W. succinogenes contain molybdopt erin guanine dinucleotide.