生理学的流体におけるチオシアネートによるヒポクロース酸のレドックスバッファリング
Michael T Ashby1, Amy C Carlson, M Jared Scott
1Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA. mashby@ou.edu
Journal of the American Chemical Society
|December 9, 2004
まとめ
ハイポクロース酸 (HOCl) は,生理学的流体内のチオシアネート (SCN-) によって調節され,自己毒性を防止します. その結果生じるヒポチオシアニット (OSCN-) は,標的型抗菌剤として作用し,哺乳類の細胞を節約します.
科学分野:
- バイオケミストリー バイオケミストリー
- 免疫学 免疫学とは
- 微生物学 微生物学とは
背景:
- 中性菌性ミエロペロキシダース (MPO) は,主要な抗菌剤としてヒポクロース酸 (HOCl) とヒポチオシアン酸 (OSCN-) を生成します.
- HOClは伝統的に主要な細胞毒性物質と考えられており,OSCNの役割はあまり理解されていません.
研究 の 目的:
- 生理学的流体におけるHOClとチオシアネート (SCN-) の相互作用を調査する.
- SCN-がHOClの活性およびその抗微生物特性を調節する役割を明らかにする.
主な方法:
- HOClとSCN−の反応を分析するための運動学的研究.
- HOCl.Cl.の反応機構と寿命を理解するための計算モデリング.
- OSCN-.の抗菌効果と哺乳類細胞毒性の評価
主要な成果:
- HOClは SCN-を素早く酸化し,非酵素反応を起こします.
- SCN-は,生理学的液体内のHOClの寿命を効果的に制限し,その自毒性を軽減します.
- 酸化等価はHOClからOSCN-.を形成するために転送されます.
- OSCN-は,哺乳類の細胞に致命的な作用を与えることなく,選択的なバイオサイド活性を示しています.
結論:
- SCN-は,HOClの反応性と毒性の重要な調節剤として作用する.
- OSCN-は,HOCl.Clと比較して,より特定で有害な抗微生物剤を表しています.
- このメカニズムは,制御された酸化ストレスを含む洗練された宿主防衛戦略を強調しています.
関連する概念動画
01:20Gas Exchange and Transport
Gas exchange, the intake of molecular oxygen (O2) from the environment and the outflow of carbon dioxide (CO2) into the environment, is necessary for cellular function. Gas exchange during respiration occurs largely via the movement of gas molecules along pressure gradients. Gas travels from areas of higher partial pressure to areas of lower partial pressure. In mammals, gas exchange occurs in the alveoli of the lungs, which are adjacent to capillaries and share a membrane with them.
02:58Balancing Redox Equations
Electrochemistry is the science involved in the interconversion of electrical and chemical reactions. Such reactions are called reduction-oxidation, or redox reactions. These important reactions are defined by changes in oxidation states for one or more reactant elements and include a subset of reactions involving the transfer of electrons between reactant species. Electrochemistry as a field has evolved to yield sufficient insights on the fundamental principles of redox chemistry and multiple...
01:27Oxygen Transport in the Blood
Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...
01:22Bicarbonate-Carbonic Acid Buffer
The carbonic acid-bicarbonate buffer system is critical for maintaining the body's pH balance. It operates on the equilibrium:
01:27Corrosion of Reinforcement
The corrosion of steel reinforcement within concrete is a process influenced by the material's inherent properties and external factors. The high pH level of around 13, provided by calcium hydroxide present in concrete, initially protects the steel reinforcement by promoting the formation of a passive iron oxide layer on its surface.
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
01:19Acid Mine Drainage
Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten aquatic...