Neutron scattering is used to study the structure of macromolecules in solution and to investigate their interactions with various binding agents such as ligands, nucleotides, and salts. One of the main advantages of the neutron technique is that the neutrons interact directly with the nuclei of molecules, in contrast to electromagnetic probes (e.g., light, x rays, and electrons), which interact with the atomic electrons. Thus, neutrons are very sensitive to the positions of the light elements (e.g., hydrogen, carbon, nitrogen, and oxygen), which are of central importance to all biological systems, In addition, hydrogen and deuterium have different neutron scattering strengths, so the isotopic substitution of D for H is routinely used to change the scattering from a system without affecting its biochemistry.
Both small-angle neutron scattering and neutron reflectivity techniques are used at the NIST Center for Neutron Research to study the structure of biological systems. Small-angle scattering is well suited for measuring bulk systems such as proteins, protein/DNA complexes, viruses, and vesicles, either dissolved or suspended in solution. Neutron reflectivity is best suited for measuring lamellar systems including lipid bilayers and multilayers, or biological and biomimetic membranes, which are often supported on a planar substrate.
Binding (biochemical); Lipid bilayers; Membrane proteins; Neutron scattering; Protein solutions; Protein-DNA complexes; Small-angle neutron scattering;