[Concentration and properties of the SH-groups of glyceraldehyde-3-phosphate dehydrogenase from the muscles of the lamprey Lampetra fluviatilis].

SH-groups of glyceraldehyde-3-phosphate dehydrogenase (GAPD) from lamprey muscle were investigated by Ellman's technique [4]. Three SH-groups per 1 monomer were determined in the presence of 8 M urea. The kinetics of the reaction of SH-groups of lamprey GADP with DTNB in non-denaturating conditions is intermediate between that of GAPD from mammalian muscles and sturgeon muscles, resembling the kinetics of SH-groups of the enzyme from halibut muscles.