title: Age-related alterations in membrane lipid and protein interactions: Arrhenius studies of microsomal glucose-6-phosphatase.
abstract: Arrhenius plots of glucose-6-phosphatase (EC 3.1.3.9) activity in liver microsomes from 6-month-old rats (young) showed discontinuities at 39, 30, 20 and 12 degrees C and change in activation energy at 20 degrees C. The enzyme activity in kidney microsomes of young rats showed essentially the same thermal discontinuities. In liver microsomes of 24-month-old rats (old) the enzyme showed discontinuities at 38, 30, 24 and 16 degrees C but not at 12 degrees C and the activation energy changed at 24 degrees C. In kidney microsomes of old rats discontinuities were seen at 38, 31, 22, 16 and 12 degrees C and the activation energy was constant from 0 to 41 degrees C. These results indicate that the interactions of membrane components are altered with age.
mesh_terms: D000375:Aging; D000818:Animals; D005952:Glucose-6-Phosphatase / Q000032:analysis*; D007668:Kidney / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D008861:Microsomes / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology; D051381:Rats; D013696:Temperature
chemical_list: D008563:Membrane Lipids; D008565:Membrane Proteins; D005952:Glucose-6-Phosphatase