Introducing SEC-SANS for studies of complex self-organized biological systems.Small-angle neutron scattering (SANS) is maturing as a method for studying complex biological structures.  In the present work, the feasibility of SEC-SANS was investigated using a series of complex and difficult samples of membrane proteins embedded in nanodisc particles that consist of both phospholipid and protein components.  It is demonstrated that SEC-SANS provides data of sufficient signal-to-noise ratio for these systems, while at the same time circumventing aggregation.  By combining SEC-SANS and SEC-SAXS data, an optimized basis for refining structural models of the investigated structures is obtained.
SEC-SANS
Introducing SEC-SANS for studies of complex self-organized biological systems.Small-angle neutron scattering (SANS) is maturing as a method for studying complex biological structures.  SANS is complementary to small-angle X-ray scattering (SAXS), in which similar contrast variation is not easily performed but in which data with superior counting statistics are more easily obtained.  This problem is enhanced in the D2O-based buffers that are typically used in SANS.  In the present work, the feasibility of SEC-SANS was investigated using a series of complex and difficult samples of membrane proteins embedded in nanodisc particles that consist of both phospholipid and protein components.  It is demonstrated that SEC-SANS provides data of sufficient signal-to-noise ratio for these systems, while at the same time circumventing aggregation.  By combining SEC-SANS and SEC-SAXS data, an optimized basis for refining structural models of the investigated structures is obtained.
SANS
SANS is complementary to small-angle X-ray scattering (SAXS), in which similar contrast variation is not easily performed but in which data with superior counting statistics are more easily obtained.  In SAXS, such problems are solved using an online size-exclusion chromatography (SEC) setup.  By combining SEC-SANS and SEC-SAXS data, an optimized basis for refining structural models of the investigated structures is obtained.
SAXS
Introducing SEC-SANS for studies of complex self-organized biological systems.Small-angle neutron scattering (SANS) is maturing as a method for studying complex biological structures.  Obtaining small-angle scattering (SAS) data on monodisperse complex biological structures is often challenging owing to sample degradation and/or aggregation.  In SAXS, such problems are solved using an online size-exclusion chromatography (SEC) setup.  In the present work, the feasibility of SEC-SANS was investigated using a series of complex and difficult samples of membrane proteins embedded in nanodisc particles that consist of both phospholipid and protein components.  It is demonstrated that SEC-SANS provides data of sufficient signal-to-noise ratio for these systems, while at the same time circumventing aggregation.  By combining SEC-SANS and SEC-SAXS data, an optimized basis for refining structural models of the investigated structures is obtained.
SEC