The role of dynamic motions in proteins will be explored with respect to entropic contributions to the stability of a protein-protein complex involved in intracellular calcium signalling. 13C and/or 2H NMR spin relaxation will be employed to characterize the extent of dynamic motions throughout the structures of calcium-saturated calmodulin as well as in a high-affinity complex of calmodulin with the smMLCK peptide. The interface of this calmodulin-smMLCK complex is expected to resemble the protein-protein interface which maintains the integrity of the transduced calcium signal. Isotopic enrichment of the smMLCK peptide will be accomplished by overexpression as a fusion protein in E. coli, enabling the dynamics of both components of this complex interface to be mapped. The pressure sensitivity of these dynamic motions will be tested with the goal of estimating activated volumes associated with the dynamic motions. Efforts will be made to detect correlated motions and to find correlations between the extent of fluidlike motions and peptide- binding. If time allows,the sequence determinants of affinity and specificity of calmodulin complexes will be examined-in collaboration with other group members in the context of structure and dynamics.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
7F32GM018114-03
Application #
2865260
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Project Start
1998-05-01
Project End
Budget Start
1998-09-01
Budget End
1999-04-30
Support Year
3
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Biochemistry
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104