Department of Microbiology, School of Life Dentistry at Tokyo, The Nippon Dental University, Chiyoda-ku, Tokyo, Japan.
Published: January 2010
AI Article Synopsis
Article Abstract
The qpo gene of Aggregatibacter actinomycetemcomitans encodes a triheme c-containing membrane-bound enzyme, quinol peroxidase (QPO) that catalyzes peroxidation reaction in the respiratory chain and uses quinol as the physiological electron donor. The QPO of A. actinomycetemcomitans is the only characterized QPO, but homologues of the qpo gene are widely distributed among many gram-negative bacteria, including Haemophils ducreii, Bacteroides fragilis, and Escherichia coli. One-third of the amino acid sequence of QPO from the N-terminal end is unique, whereas two-thirds of the sequence from the C-terminal end exhibits high homology with the sequence of the diheme bacterial cytochrome c peroxidase. In order to obtain sufficient protein for biophysical studies, the present study aimed to overproduce recombinant QPO (rQPO) from A. actinomycetemcomitans in E. coli. Coexpression of qpo with E. coli cytochrome c maturation (ccm) genes resulted in the expression of an active QPO with a high yield. Using purified rQPO, we determined the midpoint reduction potentials of the three heme molecules.
This study evaluates the effectiveness and safety of Qingpeng ointment (QPO), a Tibetan remedy, for treating symptoms of acute gouty arthritis (AGA) in patients experiencing significant joint pain.
Conducted as a randomized, double-blind, placebo-controlled trial, 203 participants with AGA received either QPO or a placebo for seven days, with joint pain and swelling being the primary outcomes measured.
The results indicated that the QPO group had reduced joint pain and swelling compared to the placebo group, along with improved joint mobility, while some mild adverse events were reported among participants, mainly skin irritations.
Blazars are active galactic nuclei (AGN) with relativistic jets whose non-thermal radiation is extremely variable on various timescales. This variability seems mostly random, although some quasi-periodic oscillations (QPOs), implying systematic processes, have been reported in blazars and other AGN. QPOs with timescales of days or hours are especially rare in AGN and their nature is highly debated, explained by emitting plasma moving helically inside the jet, plasma instabilities or orbital motion in an accretion disc.
Introduction: The Coronavirus Disease 2019 (COVID-19) pandemic continues to be a major public health problem. Vulnerable populations include older individuals with presumed weakening of the immune response. Identification of factors influencing COVID-19 infection could provide an additional means for protecting such individuals.
Introduction: Carbamoylated erythropoietin (CEPO) is a chemically engineered, nonhematopoietic derivative of erythropoietin (EPO) that retains its antidepressant and pro-cognitive effects, which are attributed to the increased expression of neurotrophic factors like brain derived neurotrophic factor (BDNF), in the central nervous system. However, the chemical modification process which produces CEPO from erythropoietin (EPO) requires pure EPO as raw material, is challenging to scale-up and can also cause batch-to-batch variability. To address these key limitations while retaining its behavioral effects, we designed, expressed and analyzed a triple, glutamine, substitution recombinant mimetic of CEPO, named QPO.
Ion sensor properties of the carboxamide and carbothioamide compounds carrying 4-quinolone group were investigated by means of emission spectrometry in methanol-water (1:1). The compounds were selectively complexed with Cu, Pd, and Fe among many metal ions. The complex stoichiometry and the stability constant were determined by fluorimetric measurements.
