Dr. J. Kent Blasie - W.H. and L.C. Annenberg Professor in the Natural Sciences
 

PHYSICAL AND BIOLOGICAL CHEMISTRY

OFFICE: 558 N
LAB: B34-36N
PHONE: (215) 898-6208
E-MAIL: jkblasie@sas.upenn.edu

Born: 1943
EDUCATION AND ACADEMIC HISTORY:

  • B.S. University of Michigan (1964)
  • Ph.D. University of Michigan (1968)
  • USPHS Career Development Award (1971-76)
  • Guest Biophysicist, Brookhaven National Laboratory (1973 - present)
  • Chairman, Department of Chemistry (1983-1986)
  • Director, Biostructures Participating Research Team, National Synchrotron Light Source, Brookhaven National Laboratory (1985-1994)
  • Executive Committee, Complex Materials Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory (1994 - present)
  • Scientific Advisory Committee, National Spallation Neutron Source, Oak RidgeNational Laboratory (1997 - present)
  • Executive Committee, Cold Neutrons for Biology and Technology Team, National Institute of Standards & Technology (1998 - present)

Research Interests

Intense beams of x-rays from undulator-based synchrotron sources and cold neutrons from reactor and spallation sources coupled with interferometric techniques now permit detailed studies of the structures and dynamics of macromolecules vectorially-oriented within a single monolayer at a soft interface. The macromolecules of interest are primarily membrane proteins and their artificial counterparts, namely de novo synthetic peptides ("maquettes") designed to possess the structural motifs present in the natural proteins and reproduce (or extend) their key biological functions without their inherent complexity. The soft interface is provided by a planar ensemble of organic chain molecules whose configurational degrees of freedom result in the softness necessary to minimally perturb the macromolecule of interest and the interactions, physical and/or chemical, are tailored synthetically to vectorially-orient the macromolecule either on the surface of or embedded within the ensemble. The techniques employed include x-ray & neutron interferometry, grazing-incidence x-ray & neutron diffraction, polarized x-ray absorption spectroscopy, time-resolved & resonance x-ray interferometry and laser-based polarized optical absorption/emission spectroscopy. While these techniques cannot provide the most desirable full 3-dimensional structure of the macromolecule at atomic-resolution, which remains to be provided only by the x-ray/neutron crystallography of 3-dimensional single crystals of the macromolecule of interest which can be problematical especially for integral membrane proteins, they can provide the desired information if good agreement with molecular dynamics computer simulations of the same system can be attained. Furthermore, these time-resolved synchrotron x-ray and cold neutron techniques can provide the kinetics of the evolution of the macromolecule's structure in response to a perturbation including its biological function on time-scales upwards from 100 picoseconds. Such results concerning the structure/dynamics and kinetics of the macromolecule within the vectorially-oriented single monolayer environment are more biologically relevant than single crystals, especially for membrane proteins and their "maquettes". An example from our approach is shown in the accompanying figures.
[Figure 1] [Figure 2] [Figure 3]