OLIGOMER

The program OLIGOMER fits an experimental scattering curve from a multicompoment mixture of proteins to find the volume fractions of each component in the mixture.

The input data for oligomer is experimental SAXS or SANS scattering curve from a mixture of several dictinct components and a set of form-factors for each component of this mixture.

The experimental scattering intensity I(s) from a mixture of K different particles (components) is written as:

I(s) = ∑(wⁱ×Iⁱ(s))

where wⁱ and Iⁱ(s) are the volume fraction and the scattering intensity from the i-th component, respectively.

Given the intensities from the components (form-factors), OLIGOMER finds the volume fractions by solving a system of linear equations using the algorithm of nonnegative or unconstrained least-squares to minimize the discrepancy between the experimental and calculated scattering curves.

X-ray or neutron form-factors of proteins with known structure or of dummy atoms models can be computed using the programs CRYSOL and CRYSONrespectively, which both are part of the ATSAS package.

转载于:https://www.cnblogs.com/greencolor/archive/2010/10/07/1845322.html