Michael Graber

Publications (2)12.74 Total impact

• Source

  Available from: unibas.ch

  Article: Electron relay race in peptides.

  Bernd Giese, Min Wang, Jian Gao, Moritz Stoltz, Pavel Müller, Michael Graber
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  ABSTRACT: A peptide assay was developed that allows the measurement of electron-transfer (ET) efficiencies in peptides. It turns out that two-step ET processes are faster than single-step reactions. This requires relay amino acids with appropriate redox potentials. Not only aromatic but also sulfur-containing aliphatic amino acids can act as stepping stones for the charge. With tryptophan, histidine, and cysteine the reaction is a more complex proton-coupled ET.
  The Journal of Organic Chemistry 05/2009; 74(10):3621-5. · 4.45 Impact Factor
• Article: Electron transfer in peptides and proteins.

  Bernd Giese, Michael Graber, Meike Cordes
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  ABSTRACT: Proteins and peptides use their amino acids as medium for electron-transfer reactions that occur either in single-step superexchange or in multistep hopping processes. Whereas the rate of the single-step electron transfer dramatically decreases with the distance, a hopping process is less distance dependent. Electron hopping is possible if amino acids carry oxidizable side chains, like the phenol group in tyrosine. These side chains become intermediate charge carriers. Because of the weak distance dependency of hopping processes, fast electron transfer over very long distances occurs in multistep reactions, as in the enzyme ribonucleotide reductase.
  Current opinion in chemical biology 10/2008; 12(6):755-9. · 8.30 Impact Factor