Fibronectins are multifunctional glycoproteins that participate in blood coagulation, cell adhesion, differentiation and embryonic development. The basis of the multifunctional activities of fibronectins appears to reside in the multidomain structure of these molecules. We propose to use electron spin resonance (ESR) spin label methods to study the dynamic interactions between different regions of the fibronectin molecule. The transglutaminase crosslinking site and free sulfhydryl groups of the protein will be modified selectively with specific spin labels. The motions of fibronectin will be determined using both conventional and Saturation Transfer ESR methods. The effects of environmental conditions (e.g., pH, temperature and ionic strength) and interactions with other physiological substances (e.g., heparin, collagen, and fibrinogen) on the conformational states of fibronectins will be evaluated. Attempts will made to investigate the similarity and/or dissimilarity in solution properties between plasma and cellular fibronectins. In addition, the transglutaminase crosslinking site and free sulfhydryl groups of the protein will also be modified selectively with specific fluorescent labels. The changes in proximity relationship between different regions of the fibronectin molecule as affected by either environmental factors or interactions with other biomolecules will be determined by using fluorescence energy transfer methods. The studies should provide a deeper understanding of the three-dimensional relationships of various regions of fibronectin. Understanding the structure and dynamics of fibronectin underlies an interpretation of the vast array of physiological functions attributed to the protein. Finally, fibronectin is a prototype protein for other adhesive proteins such as laminin and chondronectin. Our long-term objective is to study the structure and function of these cell adhesive glycoproteins and to unravel the ways in which these proteins interact with the cell surface and the dynamic structure of extracellular matrices.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM035719-05
Application #
3288818
Study Section
Biophysical Chemistry Study Section (BBCB)
Project Start
1986-01-01
Project End
1990-12-31
Budget Start
1990-01-01
Budget End
1990-12-31
Support Year
5
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Medical College of Wisconsin
Department
Type
Schools of Medicine
DUNS #
073134603
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Komarov, A M; Lai, C S (1995) Detection of nitric oxide production in mice by spin-trapping electron paramagnetic resonance spectroscopy. Biochim Biophys Acta 1272:29-36
Lai, C S; Komarov, A M (1994) Spin trapping of nitric oxide produced in vivo in septic-shock mice. FEBS Lett 345:120-4
Komarov, A M; Joseph, J; Lai, C S (1994) In vivo pharmacokinetics of nitroxides in mice. Biochem Biophys Res Commun 201:1035-42
Lai, C S; Wolff, C E; Novello, D et al. (1993) Solution structure of human plasma fibronectin under different solvent conditions. Fluorescence energy transfer, circular dichroism and light-scattering studies. J Mol Biol 230:625-40
Kar, L; Lai, C S; Wolff, C E et al. (1993) 1H NMR-based determination of the three-dimensional structure of the human plasma fibronectin fragment containing inter-chain disulfide bonds. J Biol Chem 268:8580-9
Komarov, A; Mattson, D; Jones, M M et al. (1993) In vivo spin trapping of nitric oxide in mice. Biochem Biophys Res Commun 195:1191-8
Narasimhan, C; Lai, C S (1991) Differential behavior of the two free sulfhydryl groups of human plasma fibronectin: effects of environmental factors. Biopolymers 31:1159-70
Joseph, J; Shih, C C; Lai, C S (1991) Synthesis of the spin-labeled derivative of an ether-linked phospholipid possessing high antineoplastic activity. Chem Phys Lipids 58:19-26
Squier, T C; Mahaney, J E; Yin, J J et al. (1991) Resolution of phospholipid conformational heterogeneity in model membranes by spin-label EPR and frequency-domain fluorescence spectroscopy. Biophys J 59:654-69
Wolff, C E; Lai, C S (1990) Inter-sulfhydryl distances in plasma fibronectin determined by fluorescence energy transfer: effect of environmental factors. Biochemistry 29:3354-61

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