Non-thermal effect of a ceramics radiation on a yeast glucose-6-phosphate dehydrogenase.
Non-thermal effect of a ceramics radiation on glucose-6-phosphate dehydrogenase has been investigated using the enzyme, glucose-6-phosphate and NADP+ separately irradiated at 10 degrees C by a ceracompo R plate and a ceramics un-sewed cloth (sheet). The Km for glucose-6-phosphate was increased 20% after 6 h of irradiation by the plate, but the Vmax/Km was decreased 24%. After 3 h of irradiation by the sheet, the Km was increased 17%, but after 6 h of irradiation it was decreased 11%. The 3 h of irradiation by the sheet slightly increased both enthalpy and entropy changes of the reaction, but the 6 h of irradiation significantly decreased them. Both thermodynamic parameters in the activated state were increased by the sheet irradiation. The promotion energy for both formations of the enzyme-substrate and their activated complex depended on enthalpy. The different effects of two ceramics radiators on G6PDH activity were discussed.
Kohashi
M
M
School of Food and Nutritional Sciences, University of Shizuoka, Japan.
Ohta
Y
Y
Watanabe
T
T
D002516:Ceramics; D002851:Chromatography, High Pressure Liquid; D019277:Entropy; D005948:Glucose Dehydrogenases / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects*; D019298:Glucose-6-Phosphate / Q000378:metabolism / Q000528:radiation effects; D007259:Infrared Rays; D007770:L-Lactate Dehydrogenase / Q000737:chemistry; D009249:NADP / Q000378:metabolism / Q000528:radiation effects; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013816:Thermodynamics; D013997:Time Factors
D009249:NADP; D019298:Glucose-6-Phosphate; D005948:Glucose Dehydrogenases; D007770:L-Lactate Dehydrogenase