Phosphorylation of glycolytic enzymes in hibernation.
Glycerol-3-phosphate dehydrogenase (G3PDH) and lactate dehydrogenase (LDH) were examined for differential phosphorylation, accompanying kinetics and stability inSpermophilus richardsonii liver and skeletal muscle. Hibernator G3PDH had a higher phosphate content and differential kinetics in both tissues which could be manipulated by kinase and phosphatase incubations in the G3P utilizing direction. Arrhenius plots and activation energies (Ea) showed that the hibernator form had a lower Ea in both tissues, especially in the liver.Euthermic LDH had a higher phosphate content and differential kinetics which could be manipulated by kinase and phosphatase incubations in both directions. Euthermic forms had lower Ea values in both tissues. G3PDH and LDH had differential urea I50 values with the hibernator more susceptible to urea denaturation in both tissues. Urea I50 values could be manipulated in LDH by kinase and phosphatase incubations in the liver but not in muscle.