Calories and Oxidation
Additional information on nutrient regulation of gene regulation evolved from the field of longevity research. Key genes involved in aging are regulated through SIRT1 (sirtuin 1), a gene first found in yeast. SIRT1 "monitors" the energy balance in the cell through the ratio of NAD+/NADH. Caloric restriction increases NAD levels which activates SIRT1. The protein encoded by this gene is a histone deactylase which alters chromatin structure and hence expression of genes. In yeast and other model systems, calorie restriction increases life span.
The ability to prevent oxidation also decreases with age, which leads to damage to proteins, membranes, and mitochondria. Oxidation alters protein structure directly or through changes in membrane fluidity and increases the Km (lowers affinity) of coenzymes for enzymes. Increased levels of vitamin precursors may be needed to restore full activity of these enzymes.
Ames, BN, Suh, JH, Liu, J. 2006. Enzymes Lose Binding Affinity (Incrased Km) for Coenzymes and Substrates with Age: A Strategy for Remediation. In Nutritional Genomics: Discovering the Path to Personalized Nutrition. Kaput, J and Rodriguz, R (eds). Wiley and Sons, Inc. NY. 2006.
Lin, S-J. 2006. Molecular Mechanisms of Longevity Regulation and Calorie Restriction. In Nutritional Genomics: Discovering the Path to Personalized Nutrition. Kaput, J and Rodriguz, R (eds). Wiley and Sons, Inc. NY. 2006.