Small-Angle Scattering (SAS), including Small-Angle X-ray and Neutron Scattering (SAXS and SANS), is a powerful characterization technique for investigating the structure of biomacromolecules and their interactions. SAXS/SANS allows us to characterize structural features across a wide range of length scales, spanning from just a few nanometers to several hundred nanometers. Furthermore, SANS offers unique advantages through contrast matching, enabling the characterization of individual components within complex structures and providing insights into the hydration states of the measured materials. Our research group employs SAXS/SANS to investigate biomacromolecular interactions with the primary objective of gaining a deeper understanding of their biological functions and material properties. Utilizing SANS/SAXS as major characterization method, our research extends into three distinct directions: 1) Predicting the conformational flexibility and stability of therapeutic proteins in various formulations; 2) Understanding the phase behavior of protein/polymer complexes in crowded environments; 3) Elucidating the mechanism of action of aluminum adjuvants in vaccine formulations. In this presentation, I will demonstrate how we leverage SAXS and SANS to achieve these research objectives.
Dr. Amy Xu completed her Ph.D. in Chemistry from the University of Auckland, New Zealand. During her doctoral research, she investigated how proteins and polysaccharides interacted with each other during a liquid-liquid phase separation process known as complex coacervation, using mainly small-angle X-ray and neutron scattering (SAXS/SANS) techniques. Upon completing her Ph.D. in 2016, Dr. Xu relocated to the US to undertake her first postdoctoral position at the University of Massachusetts Amherst, where she investigated the relationship between molecular structures and preparation conditions to the phase behavior and rheological properties of colloid-polymer complexes. From 2017 to 2020, she pursued her second postdoctoral training at the National Institute of Standards and Technology (NIST) in Maryland. Her work at NIST centered on advancing small-angle scattering techniques to study the conformational flexibility and stability of monoclonal antibodies in concentrated formulations. She joined LSU in August 2020 as an Assistant Professor in Chemistry. Dr. Xu's research at LSU primarily aims to achieve a comprehensive understanding on how biomacromolecules behave and interact in confined environments, from complex coacervates to concentrated protein formulations, using biophysical characterization methods, especially SAXS and SANS.