Piotr Fajer | Homepage

Professor of Biological Sciences

Research Interests

Energy Transduction

The long-term goal of this project is to understand the energy transduction of ATP into mechanical work in muscle. Current projects in this area include: 1) Determination of the internal shape changes within the myosin head by fluorescence energy transfer, 2)Modulation of the head dynamics and shape by light chain phosphorylation, saturation transfer EPR and FRET, and 3) Kinetics of the structural changes--caged ATP, caged Ca with EPR and FRET.

Ca²⁺ Activation

Muscle contraction is initiated by the binding of Ca2+ to the thin filament. This signal somehow results in a changed interaction between the myosin head and actin. Since Ca2+ binds to troponin C, a protein which is not in direct contact with either myosin or actin, the signal must be propagated via the other regulatory proteins, troponin I, troponin T and tropomyosin. The nature of these interactions is not well understood. Current projects include: * Description of differences in structural changes as induced by crossbridge binding in contrast to those following Ca binding--EPR, fluorescence energy transfer * Kinetics of distance changes between actin and troponin I--caged Ca and transient FRET * Site directed mutagenesis of troponin C.

Instrument & Method Development

My lab is involved in the development of various aspects of EPR: * Development of theoretical prediction (simulation) of experimental spectra * Development of statistical methods to fit the simulations to experimental spectra * Development of new techniques, time-resolved EPR and the high field EPR.

Teaching