[Isolation and several properties of the glyceraldehyde-3-phosphate dehydrogenase from the muscles of the lamprey Lampetra fluviatillis].

Procedure for isolation of electrophoretically homogeneous, crystalline glyceraldehyde-3-phosphate dehydrogenase from lamprey muscles is described. Amino acid composition of the enzyme was investigated and compared with that of the same dehydrogenase from other sources. With respect to its secondary structure and kinetic parameters, the lamprey enzyme does not significantly differ from those of other animals. Activation energy for the lamprey enzyme is lower than for the same enzyme from endothermic animasl. "Temperature modulation" of Michaelis constant described in the literature, was not confirmed for the lamprey enzyme in the range of physiological pH values.