Rezumat articol ediţie STUDIA UNIVERSITATIS BABEŞ-BOLYAI

În partea de jos este prezentat rezumatul articolului selectat. Pentru revenire la cuprinsul ediţiei din care face parte acest articol, se accesează linkul din titlu. Pentru vizualizarea tuturor articolelor din arhivă la care este autor/coautor unul din autorii de mai jos, se accesează linkul din numele autorului.

 
       
         
    STUDIA CHEMIA - Ediţia nr.4 din 2007  
         
  Articol:   AN ALTERNATIVE MECHANISM FOR CATALASE ACTIVITY.

Autori:  RADU SILAGHI-DUMITRESCU. 		 
       
         
  Rezumat:   The ferric heme active sites of enzymes such as catalases and peroxidases react with hydrogen peroxide to generate a “high-valent” (formally, Fe(V)) species, known as Compound I. In peroxidases, Compound I generally decays back to the ferric state by abstracting electrons from various organic substrates or redox proteins. In catalases, the electrons required for Compound I reduction are supplied by a second H2O2 molecule. It has long been implied that the reaction between Compound I and H2O2 in catalase implies either outer-sphere electron transfer and/or hydrogen/proton abstraction mechanisms. Recent DFT calculations have confirmed that such mechanisms may be viable. However, a recent experimental investigation by Obinger and co-workers now prompts us to investigate an alternative mechanism, whereby the oxygen atom in Compound I is substituted by a second peroxide molecule, generating a formally Fe(V)-peroxo adduct which by electromerism would convert to Fe(III) and liberate the final product, O2. Reported here are DFT calculations illustrating the theoretical viability of this newly proposed catalase mechanism.  
         
     
         
         
      Revenire la pagina precedentă