The molecular chaperone, αB-crystallin, has the ability to prevent amorphous and fibrillar aggregation of proteins implicated in human diseases, e.g. cataract and amyloidoses. Co-localization of αB-crystallin with  α-synuclein in Lewy bodies and evidence for their interaction in vitro suggest an involvement of αB-crystallin in the response to Parkinson's disease.  

Small-angle scattering (SAXS and SANS techniques) encompasses various approaches to low-resolution structural studies of molecules, and thus complements the two mainstream techniques: X-ray crystallography and NMR.  Thus, instead of providing detailed structural information of atomic resolution, small angle scattering is best for modelling shapes and intermolecular orientation of biomolecules, as well as dynamical studies of folding or ligand-binding.  The main advantage is that the sample need not be crystalline and the compounds can be studied in native conditions, and is not limited by molecular weight.  In neutron scattering, selective information on 3-dimensional structure of individual component proteins or subunits can be yielded by varying contrast between different molecules using differentially deuterated components. 

The National Deuteration Facility at ANSTO offers biological and chemical deuteration of molecules for the neutron beam and NMR user communities.  73% deuterated αB-crystallin was produced with structural and functional characteristics consistent with those of hydrogenated αB-crystallin.

We studied interactions of αB-crystallin with α-synuclein by SANS on NG7 beamline at NCNR, USA.  Each component was measured at three neutron contrast points (40%, 70% and 99% D2O).  No structural changes were seen in either protein over 4 hr at 37^oC.  Consistent with previous models, αB-crystallin molecule formed a globular oligomer.  Ab initio shape models of α-synuclein were consistent with previous data showing elongated shapes.  Data of the complex in 40% and 70% D₂O  indicated a progressive increase in dimensions with time.  This might indicate formation of a complex in which α-synuclein molecules intercalate and displace αB-crystallin subunits.