Surface layer protein characterization by small angle x-ray scattering and a fractal mean force concept: From protein structure to nanodisk assemblies

Journal Article · Sun Nov 07 00:00:00 EDT 2010 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3489682· OSTI ID:21559946

Horejs, Christine; Pum, Dietmar; Sleytr, Uwe B ^[1]; Peterlik, Herwig ^[2]; Jungbauer, Alois; Tscheliessnig, Rupert ^[3]

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1. Department for Nanobiotechnology, University of Natural Resources and Applied Life Sciences, 1090 Vienna (Austria)
2. Faculty of Physics, University of Vienna, 1090 Vienna (Austria)
3. Institute for Applied Microbiology, University of Natural Resources and Applied Life Sciences, 1190 Vienna (Austria)

Surface layers (S-layers) are the most commonly observed cell surface structure of prokaryotic organisms. They are made up of proteins that spontaneously self-assemble into functional crystalline lattices in solution, on various solid surfaces, and interfaces. While classical experimental techniques failed to recover a complete structural model of an unmodified S-layer protein, small angle x-ray scattering (SAXS) provides an opportunity to study the structure of S-layer monomers in solution and of self-assembled two-dimensional sheets. For the protein under investigation we recently suggested an atomistic structural model by the use of molecular dynamics simulations. This structural model is now refined on the basis of SAXS data together with a fractal assembly approach. Here we show that a nondiluted critical system of proteins, which crystallize into monomolecular structures, might be analyzed by SAXS if protein-protein interactions are taken into account by relating a fractal local density distribution to a fractal local mean potential, which has to fulfill the Poisson equation. The present work demonstrates an important step into the elucidation of the structure of S-layers and offers a tool to analyze the structure of self-assembling systems in solution by means of SAXS and computer simulations.

• OSTI ID: 21559946
• Journal Information: Journal of Chemical Physics, Vol. 133, Issue 17; Other Information: DOI: 10.1063/1.3489682; (c) 2010 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BIOPHYSICS
COMPUTERIZED SIMULATION
DENSITY FUNCTIONAL METHOD
FRACTALS
INTERACTIONS
LAYERS
MOLECULAR DYNAMICS METHOD
MOLECULAR STRUCTURE
MONOMERS
POISSON EQUATION
PROTEIN STRUCTURE
PROTEINS
SMALL ANGLE SCATTERING
SOLIDS
SOLUTIONS
STRUCTURAL MODELS
SURFACES
X-RAY DIFFRACTION
CALCULATION METHODS
COHERENT SCATTERING
DIFFERENTIAL EQUATIONS
DIFFRACTION
DISPERSIONS
EQUATIONS
HOMOGENEOUS MIXTURES
MIXTURES
ORGANIC COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
PHYSICS
SCATTERING
SIMULATION
VARIATIONAL METHODS