Abstract

Our studies on polyomavirus, tobacco mosaic virus and gap junction membranes are focused on correlating their structures with the dynamic processes in their formation, interactions and stability. Analyses of disorder in simpler protein structures will exemplify the molecular movements involved in the switching mechanisms of virus and membrane assemblies. Our studies involve the coordinated applications of methods of X-ray diffraction, electron microscopy, physical biochemistry, molecular biology and computer graphics. Polyomavirus structure and assembly are being investigated by electron microscopy of self-assembling capsid proteins produced from the recombinant expression vector; by X-ray crystallography of the intact virion and recombinant capsid proteins; and by measurement of diffuse X-ray scattering from the disordered minichromosome core of crystalline virions. Tobacco mosaic virus asembly and interactions are being investigated by X-ray and electron crystallography to refine computer-generated models of the polymorphic disk aggegates; by correlating physical- chemical and structural data to analyze electrostatic interactions involved in switching assembly; and by optical and X-ray diffraction analysis of colloidal states or organization of viruses and protein particles. Gap junction connexion structure and gating mechanisms are being investigated by computer modeling of the beta-sheet structure of the connexon channel based on X- ray and electron crystallographic data; by measurement of variations in the surface structure; and by correlating structure and sequence data. Movement in macromolecular structures is being investigated by measurement of diffuse X-ray scatter from insulin and lysozyme crystals; by correlated X-ray diffraction, optical and model simulation of tropomyosin crystals; and by application of similar methods to disordered virus and membrane structures. Technological developments include use of the CCD- based X-ray area detector to record diffraction data that could not be obtained by conventional methods; and application of computer graphics mehtods to relate higher levels of organization to the underlying molecular structure.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Unknown (R35)
Project #
5R35CA047439-04
Application #
3479653
Study Section
Special Emphasis Panel (SRC (88))
Project Start
1988-05-01
Project End
1995-04-30
Budget Start
1991-05-01
Budget End
1992-04-30
Support Year
4
Fiscal Year
1991
Total Cost
Indirect Cost

  Institution

Name
Brandeis University
Department
Type
Organized Research Units
DUNS #
616845814
City
Waltham
State
MA
Country
United States
Zip Code
02454

  Publications

Adamek, D H; Guerrero, L; Blaber, M et al. (2005) Structural and energetic consequences of mutations in a solvated hydrophobic cavity. J Mol Biol 346:307-18
Diao, Jiasheng (2003) Crystallographic titration of cubic insulin crystals: pH affects GluB13 switching and sulfate binding. Acta Crystallogr D Biol Crystallogr 59:670-6
Twigg, P D; Parthasarathy, G; Guerrero, L et al. (2001) Disordered to ordered folding in the regulation of diphtheria toxin repressor activity. Proc Natl Acad Sci U S A 98:11259-64
King, C Y (2001) Supporting the structural basis of prion strains: induction and identification of [PSI] variants. J Mol Biol 307:1247-60
Diaz-Avalos, R; Caspar, D L (2000) Hyperstable stacked-disk structure of tobacco mosaic virus protein: electron cryomicroscopy image reconstruction related to atomic models. J Mol Biol 297:67-72
Twigg, P D; Wylie, G P; Wang, G et al. (1999) Expression and assignment of the 1H, 15N, and 13C resonances of the C-terminal domain of the diphtheria toxin repressor. J Biomol NMR 13:197-8
Wang, G; Wylie, G P; Twigg, P D et al. (1999) Solution structure and peptide binding studies of the C-terminal src homology 3-like domain of the diphtheria toxin repressor protein. Proc Natl Acad Sci U S A 96:6119-24
Yu, B; Blaber, M; Gronenborn, A M et al. (1999) Disordered water within a hydrophobic protein cavity visualized by x-ray crystallography. Proc Natl Acad Sci U S A 96:103-8
Zhou, G; Somasundaram, T; Blanc, E et al. (1998) Transition state structure of arginine kinase: implications for catalysis of bimolecular reactions. Proc Natl Acad Sci U S A 95:8449-54
Diaz-Avalos, R; Caspar, D L (1998) Structure of the stacked disk aggregate of tobacco mosaic virus protein. Biophys J 74:595-603

Showing the most recent 10 out of 33 publications