Scattering from phase-separated vesicles I. An analytical form factor for multiple static domains

Abstract

This is the first in a series of papers considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, smallangle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison to simulated data obtained from a Monte Carlo method. Several aspects of the analytical solution for scattered intensity are discussed in the context of small angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. The analysis indicates that effects of domain formation are most pronounced when the vesicle’s average scattering length density matches the surrounding solvent.