Effects of elasticity on biological assemblies
Svetlana Morozova, Kathryn Wilcox, Grace Kemerer, Marlee Dingle, Alexandra Grinevich
Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland OH 44106
The elasticity of complex macromolecules is critical for biological function. The mechanical properties of helical polypeptides help the functions of many protein levers and motors, as well as help control the self-assembly of collagen. As the most abundant protein in mammals, collagen is a major structural protein in the extracellular matrix (ECM), which is found in cartilage, hair, skin, and vitreous in the eye. Collagen’s key structure is the triple helix that assembles into fibrils in the ECM, which provide mechanical strength. One of the main open questions in structural biology is what controls the size scales of these assemblies. In order to determine the structure-property relationships in proteins and tissues such as the ECM, we have investigated the mechanical properties of biological helices (poly(l-lysine) and collagen type II) and how flexibility controls their assembly using scattering and electron microscopy techniques. In addition, many biological assemblies occur in an elastic matrix. We have investigated the influence of the elastic matrix on biological assembly using model poly(l-lysine) (PLL) and hyaluronic acid (HA) coacervate systems. Without the matrix, PLL and HA phase separated into a bulk coacervate phase. Within a polyacrylamide gel, the phase is constrained to a limited size scale, controlled by the matrix elasticity and depth into the gel. This systemic study of the mechanics of biological helices and their environments will lead to a better understanding of the limiting size scales in biological assemblies.
BIO: Dr. Svetlana Morozova is an Assistant Professor of Macromolecular Science and Engineering at Case Western Reserve University. Dr. Morozova’s lab is broadly focused on studying polymer dynamics in solutions and gels by setting up new scattering techniques. A particular interest in the lab is the effect of polymer flexibility on bulk properties such as viscosity and modulus, and the effects of anisotropy of the environment on polymer diffusion near surfaces. These processes are relevant to protein dynamics in cells, fluid flows, droplet formation, and filtration devices. Recently, Dr. Morozova has been awarded the ACS PRF Doctoral New Investigator, Lubrizol Innovation Prize, and NSF CAREER awards. Before joining CWRU in July 2019, Dr. Morozova worked as a post-doctoral researcher in the Department of Chemistry at University of Minnesota Twin Cities. She received her Ph. D. in Polymer Science and Engineering from University of Massachusetts at Amherst in 2017.
Host: Lydia Kisley