Background
Information about macromolecules is encoded in their shape and the way they are assembled.
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X-ray scattering methods are important tools for investigating the structure and interactions between complex molecular systems.
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The analysis of solution X-ray scattering data of self-assembled macromolecular complexes is much less established compared to crystallography or even dilute protein solutions.
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Thus, there is a need for different approaches when performing measurements and when analyzing data to solve the structure of macromolecules.
Our Innovation
A user-friendly, comprehensive, computationally accelerated software program for the analysis of radially integrated signals of solution X-ray scattering from supramolecular self-assembled structures was developed. It can address both the form and structure factor contributions to the signal.
Technology
Our approach applied scattering theory to derive the explicit form factors of various models such Gaussian spheres, Gaussian cylinders, uniform cylinders, helical structures or cylindroids as that are useful for evaluating solution X-ray scattering signals from supramolecular self-assembled structures.
Fig.1: Illustration of spherical shells with Gaussian electron density
Fig. 2. Illustration of coaxial helical models. The figure on the left describes coaxial shifted thick uniformhelices. On the right, the helices are composed of discrete uniform spheres. X+ program was developed to model multilayer single geometry-based structures that may also be in Space-Filling lattices. The geometries include rectangular cuboids, a stack of layered structures, multiple spherical shells, concentric hollow cylindrical or distorted cylindrical structures, or a series of coaxial shifted helical structures. Each layer or subunit has an electron density profile that can be uniform, Gaussian, or a sum of hyperbolic tangents. Its features include phase fitting algorithms to obtain lattice parameters and peak indices, model resolution function, and sample polydispersity. D+ program was designed to accurately compute the solution X-ray scattering curves from supramolecular structures by docking repeating subunits into their assembly symmetry.
Fig.3: Analysis at increased resolution of microtubule
Applications for use:
System may be used for analyzing all types of large molecular structures in solution, such as:
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Viruses
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Microtubules
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Nanostructures
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Membranes
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Liquid crystals
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Polymer assemblies
