Professor of Biochemistry and Biophysics

Location: 220 Anatomy-Chemistry Building/6059
Tel: (215) 898-8787 (Office)/(215) 898-7064 (Lab)
Fax: (215) 898-8559
E-mail: yonetant@mail.med.upenn.edu

Ph.D. Osaka University (1953)


DESCRIPTION OF RESEARCH INTERESTS:

Dr. Yonetani investigates the structure-function correlations in hemoglobins, cytochromes, and peroxidases to elucidate the mechanism or action of these hemoglobins. Molecular structure, reactivity, and interactions of these hemoproteins with ligands, substrates, inhibitors, and allosteric effectors, are probed by chemical and genetical alterations of the molecular structure, EPR, NMR, FTIR, fluorescence, and resonance Raman examinations of the molecular structure as well as kinetic and thermodynamic measurements of their reactions.

• Ligand binding dynamics in myoglobin
  Chemical and genetical alterations of myoglobin, spectroscopic characterization of molecular structures, and kinetic and thermodynamic determination of ligand binding dynamics are used to elucidate the structural basis of the ligand reactivity in myoglobin.
  
• Allosteric mechanism in hemoglobin
  Preparation of metal-substituted hybrid hemoglobins and chemically modified hemoglobins. Structure and function characterization of these modified hemoglobins to probe their allosteric and cooperative mechanism.
  
• The mechanism of action of cytochrome c peroxidase
  The mode of interaction and the mechanism of electron transfer between cytochrome c peroxidase and cytochrome c are probed by transient kinetic and thermodynamic measurements.
  

1. Yonetani, T. and M. Laberge (2008) Protein dynamics explain the allosteric behaviors of hemoglobin. Biochim. Biophys. Acta-Proteins and Proteomics [in press].
2. Laberge, M. and T. Yonetani (2008) Molecular dynamics simulations of hemoglobin A in different quaternary states and bound to DPG: Perturbation of tertiary conformations and HbA dynamics in the presence of homotropic effects. Biophys. J. 94:2737-2751.
3. Egawa, T., A. Tsuneshige, M. Suematsu, M., and T. Yonetani (2007) New method for determinations of association and dissociation rate constants of reversible biomolecular reactions by isothermal titration calorimetry. Anal. Chem. 79:2972-2978.
4. Yokoyama, T., S.-Y. Park, A. Tsuneshige, S. Neya, T. Yonetani, and J. M. Tame (2006) Crystal structures of deoxy human and carbonmonoxy horse hemoglobin bound to the effector molecule L35. J. Mol. Biol. 365:790-801.
5. Yonetani, T. and A. Tsuneshige (2003) The global allostery model of hemoglobin: The allosteric mechanism involving homotropic and heterotropic interactions. Com. Rend. Biologies 326:523-532.
6. Yonetani, T., S. Park, A. Tsuneshige, A., K. Imai, and K. Kanaori. (2002) Global allostery model of hemoglobin: Modulation of O₂-affinity, cooperativity, and Bohr effect by heterotropic allosteric effectors. J. Biol. Chem. 277:34508-34520.