Thrombosis or clotting, is the cause of 50% of deaths in North America. However, blood coagulation is essential in arresting hemorrhaging. Thus, there must be a delicate balance betwen these processes. When this balance is disturbed, patients suffer from hemphilia, strokes, heart attacks and cardiovascular disease. Heparin, a negatively charged polysaccharide, is a potent anticoagulant which ihnhibits blood clotting. The protein platelet factor 4 plays a key role in blood coagulation.
Our major focus is on the application of nuclear magnetic resonance spectroscopy to study the structure and function of platelet factor 4 and other platelet proteins, in particular the novel bovine platelet plasmin inhibitor. Nuclear magnetic resonance techniques are used to examine the environments of individual amino acids in proteins. The assignment of the resonance requires the applications of protein chemical techniques. These studies enable us to ascertain the role of specific amino acids in the structure of the platelet protein, to determine their contributions to heparin binding, and to probe protein conformation.
Our interests also extend to thymosin alpha 1, a peptide which is used in clinical trials for the treatment of hepatitis b, and ArsC, a protein which confers arsenate resistance to cells and is homologous to the multidrug resistance proteins. The elucidation of the structure of these peptides and proteins provides insights into their function.
- Baldwin, J.S., Lee, L., Leung, T.K., Muruganandam, A., Mutus, B. Identification of the Site of Non- enzymatic Glycation of Glutathione Peroxidase: Rationalization of the Glycation-Related Catalytic Alterations on the Basis of 3-D Protein Structure., Biochimica et Biophysica Acta, in press (1994).
- Veenstra, T.D., Lee, L. NMR Investigation of the Position of Histidine-119 in the Complex of Ribonuclease A with Uridine Vanadate in Solution, Biophysical J. 67, 331-335 (1994).
- Talpas, C.J., Lee, L. Comparative Studies of the Interaction of Human and Bovine Platelet Factor 4 with Heparin Using Histidine NMR Resonances as Spectroscopic Probes. J. Protein Chemistry 12, 303-309 (1993).
- Cederholm, M.T., Stuckey, J.A., Doscher, M.S., Lee, L. Histidine pKa Shifts Accompanying the Inactivating D121N Substitution in a Semisynthetic Bovine Pancreatic Ribonuclease, Proc. Natl. Acad. Sci. USA 88, 8116-8120 (1991).
- Talpas, C.J., Walz, D.A., and Lee, L. 1H NMR Studies of Bovine Platelet Factor 4: Histidine Assignments and Interactions with Heparin, Biochimica et Biophysica Acta 1078, 208-218 (1991).
- Kim, H.S., Lee, L., and Evans, D.R. Identification of the ATP Binding Sites of the Carbamyl Phosphate Synthetase Domain of CAD, the Multifunctional Protein that Initiates Pyrimidine Biosynthesis in Mammalian Cells, Biochemistry 30, 10322-10329 (1991).