Model building of a molluscan hemocyanin from X-ray solution scattering.

Molluscan hemocyanins are proteins of a truly enormous size. Because of this, determination of their quaternary structure at high resolution cannot easily be obtained by standard methods such as X-ray crystallography and NMR. Therefore, different approaches, using several low-resolution techniques are currently necessary to understand hemocyanin structure. In this work a model of the Rapana venosa hemocyanin has been obtained from a template model and small angle X-ray scattering (SAXS) data. The template model was built from the electron density of the closely related Haliotis tuberculata hemocyanin and a computer program was written to fit this model to the SAXS data using the simulated annealing algorithm.