Link between depression and bone mineral density in Cooper Center Longitudinal Study: Indirect effects of vitamin D, inflammation, and physical activity.

Background: To examine the effect of depressive symptom severity on bone mineral density (BMD) and the potential mediators of the relationship.

Method: This study used data from n = 7273 participants in the Cooper Center Longitudinal Study at the Cooper Clinic in Dallas. Participants were included if they had data for all study variables, including left and right femoral neck (BMD), age, sex, body mass index, smoking status, antidepressant (SSRI/SNRI) use, standard alcoholic drinks consumed per week, and depressive symptom severity as measured with the Center for Epidemiological Studies-Depression (CESD)-10.

[FeFe]-hydrogenase maturation: insights into the role HydE plays in dithiomethylamine biosynthesis.

HydE and HydG are radical S-adenosyl-l-methionine enzymes required for the maturation of [FeFe]-hydrogenase (HydA) and produce the nonprotein organic ligands characteristic of its unique catalytic cluster. The catalytic cluster of HydA (the H-cluster) is a typical [4Fe-4S] cubane bridged to a 2Fe-subcluster that contains two carbon monoxides, three cyanides, and a bridging dithiomethylamine as ligands. While recent studies have shed light on the nature of diatomic ligand biosynthesis by HydG, little information exists on the function of HydE.

pH optimum of the photosystem II H₂O oxidation reaction: effects of PsbO, the manganese-stabilizing protein, Cl- retention, and deprotonation of a component required for O₂ evolution activity.

Hydroxide ion inhibits Photosystem II (PSII) activity by extracting Cl(-) from its binding site in the O(2)-evolving complex (OEC) under continuous illumination [Critchley, C., et al. (1982) Biochim.

Probing the topography of the photosystem II oxygen evolving complex: PsbO is required for efficient calcium protection of the manganese cluster against dark-inhibition by an artificial reductant.

The photosystem II (PSII) manganese-stabilizing protein (PsbO) is known to be the essential PSII extrinsic subunit for stabilization and retention of the Mn and Cl(-) cofactors in the oxygen evolving complex (OEC) of PSII, but its function relative to Ca(2+) is less clear. To obtain a better insight into the relationship, if any, between PsbO and Ca(2+) binding in the OEC, samples with altered PsbO-PSII binding properties were probed for their potential to promote the ability of Ca(2+) to protect the Mn cluster against dark-inhibition by an exogenous artificial reductant, N,N-dimethylhydroxylamine. In the absence of the PsbP and PsbQ extrinsic subunits, Ca(2+) and its surrogates (Sr(2+), Cd(2+)) shield Mn atoms from inhibitory reduction (Kuntzleman et al.