The binding of fluoride ion to bovine cuprozinc superoxide dismutase as studied by 19F magnetic relaxation

The Contribution of Fluoride to the Pathogenesis of Eye Diseases: Molecular Mechanisms and Implications for Public Health

This study provides diverse lines of evidence demonstrating that fluoride (F) exposure contributes to degenerative eye diseases by stimulating or inhibiting biological pathways associated with the pathogenesis of cataract, age-related macular degeneration and glaucoma. As elucidated in this study, F exerts this effect by inhibiting enolase, τ-crystallin, Hsp40, Na⁺, K⁺-ATPase, Nrf2, γ -GCS, HO-1 Bcl-2, FoxO1, SOD, PON-1 and glutathione activity, and upregulating NF-κB, IL-6, AGEs, HsP27 and Hsp70 expression. Moreover, F exposure leads to enhanced oxidative stress and impaired antioxidant activity. Based on the evidence presented in this study, it can be concluded that F exposure may be added to the list of identifiable risk factors associated with pathogenesis of degenerative eye diseases. The broader impact of these findings suggests that reducing F intake may lead to an overall reduction in the modifiable risk factors associated with degenerative eye diseases. Further studies are required to examine this association and determine differences in prevalence rates amongst fluoridated and non-fluoridated communities, taking into consideration other dietary sources of F such as tea. Finally, the findings of this study elucidate molecular pathways associated with F exposure that may suggest a possible association between F exposure and other inflammatory diseases. Further studies are also warranted to examine these associations.

The active site of manganese-containing superoxide dismutase from Bacillus stearothermophilus studied by 1H and 19F magnetic relaxation

The dependence of the magnetic relaxation rates of 1H and 19F- on temperature, frequency, pH and N-3 concentration, were measured in solutions of Manganese-containing superoxide dismutase of Bacillus stearothermophilus, and were compared to activity measurements, in order to obtain some information on the structure and dynamics at Mn(III) present in the active site of the enzyme. The experimental data lead us to hypothesize the presence of two binding sites in the coordination sphere of the enzyme bound Mn(III), which are accessible to water and anions and have different chemical and spectroscopic properties. NMR measurements carried out in the presence of competitive inhibitors and the pH dependence of both NMR relaxation rates suggest that F-, N-3 and OH- ions bind to one site, while a water molecule binds to the other one. The stability constant values of the complexes between these anions and the enzyme are reported. The influence of the anions on activity and the pH dependence of NMR parameters are discussed.