A meta-analysis and review examining a possible role for oxidative stress and singlet oxygen in diverse diseases

From kinetic data (k, T) we calculated the thermodynamic parameters for various processes (nucleation, elongation, fibrillization, etc.) of proteinaceous diseases that are related to the β-amyloid protein (Alzheimer's), to tau protein (Alzheimer's, Pick's), to α-synuclein (Parkinson's), prion, amylin (type II diabetes), and to α-crystallin (cataract). Our calculations led to G= values that vary in the range 92.8–127 kJ mol–1 at 310 K. A value of ~10–30 kJ mol–1 is the activation energy for the diffusion of reactants, depending on the reaction and the medium. The energy needed for the excitation of O2 from the ground to the first excited state (1g, singlet oxygen) is equal to 92 kJ mol–1. So, the G= is equal to the energy needed for the excitation of ground state oxygen to the singlet oxygen (1g first excited) state. The similarity of the G= values is an indication that a common mechanism in the above disorders may be taking place. We attribute this common mechanism to the (same) role of the oxidative stress and specifically of singlet oxygen, (1g), to the above-mentioned processes: excitation of ground state oxygen to the singlet oxygen, 1g, state (92 kJ mol–1), and reaction of the empty * orbital with high electron density regions of biomolecules (~10–30 kJ mol–1 for their diffusion). The G= for cases of heat-induced cell killing (cancer) lie also in the ab...
Source: Biochemical Journal - Category: Biochemistry Authors: Tags: Hypotheses Source Type: research