Porphyromonas gingivalis hydrogen sulfide enhances methyl mercaptan-induced pathogenicity in mouse abscess formation.

Porphyromonas gingivalis produces hydrogen sulfide (H2S) from l-cysteine. However, the role of H2S produced by P. gingivalis in periodontal inflammation is unclear.

Bone Formation Is Coupled to Resorption Via Suppression of Sclerostin Expression by Osteoclasts.

Bone formation is coupled to bone resorption throughout life. However, the coupling mechanisms are not fully elucidated. Using Tnfrsf11b-deficient (OPG ) mice, in which bone formation is clearly coupled to bone resorption, we found here that osteoclasts suppress the expression of sclerostin, a Wnt antagonist, thereby promoting bone formation.

Aberrant TRPV1 expression in heat hyperalgesia associated with trigeminal neuropathic pain.

Trigeminal neuropathic pain is a facial pain syndrome associated with trigeminal nerve injury. However, the mechanism of trigeminal neuropathic pain is poorly understood. This study aimed to determine the role of transient receptor potential vanilloid 1 (TRPV1) in heat hyperalgesia in a trigeminal neuropathic pain model.

Conversion of the metal-specific activity of Escherichia coli Mn-SOD by site-directed mutagenesis of Gly165Thr.

Glycine 165, which is located near the active site metal, is mostly conserved in aligned amino acid sequences of manganese-containing superoxide dismutase (Mn-SOD) proteins, but is substituted to threonine in most iron-containing SODs (Fe-SODs). Because threonine 165 is located between Trp128 and Trp130, and Trp128 is one of the metal-surrounding aromatic amino acids, the conversion of this amino acid may affect the metal-specific activity of Escherichia coli Mn-SOD. In order to clarify this possibility, we prepared a mutant of E.

Effects of substrate analogues and pH on manganese superoxide dismutases.

The effect of the substrate analogues azide and fluoride on the manganese(II) zero-field interactions of different manganese-containing superoxide dismutases (SOD) was measured using high-field electron paramagnetic resonance spectroscopy. Two cambialistic types, proteins that are active with manganese or iron, were studied along with two that were only active with iron and another that was only active with manganese. It was found that azide was able to coordinate directly to the pentacoordinated Mn(II) site of only the MnSOD from Escherichia coli and the cambialistic SOD from Rhodobacter capsulatus.