The Solution Physics of F-Actin and Filamentous Bacteriophages

Indiana University, Bloomington IN

Investigators

Abstract

This individual investigator award is to a young professor at Indiana University for research that focuses on the intermolecular interactions of filamentous biopolymers, their assembly into distinct physical states, and transitions between the states. The major part of the program will use the protein filament F-actin, which is abundant in both muscle and non-muscle cells and is essential for cell motility and locomotion. A fraction of experiments will also be performed using filamentous viruses fd, Ml3 and pfl, as alternative biopolymers to compare with the physical properties of F-actin. The overall goal is to define experimentally a number of self-organized states and phase transitions in solutions of these biopolymers. The knowledge obtained in this proposal is directly relevant to biological phenomena such as the network and bundle formation of F-actin in many cell types. Elucidating the molecular interactions that govern the formation of various physical states will provide a means to predict and manipulate transitions among them, and therefore have potential applications for materials science and biomedical engineering. Participating graduate students will receive valuable training in applying physics concepts to complex biomaterials, and consequently acquire practical skills necessary to potentially succeed in a growing job market involving bioengineering and medically oriented research in both academic institutions and the biotechnology industry. %%% This individual investigator award is to a young professor at Indiana University for a project that aims to study physical properties of protein filaments and filamentous viruses, which are common and relatively simple biological entities. The major part of the study focuses on an abundant cellular protein actin that can be readily purified from muscle tissues, but it is also a crucial component in non-muscle cells. In fact, the dynamic self-assembly of actin into filamentous and crosslinked forms is the most important factor for cellular shape change and migration. Our goal is to experimentally define the physical interactions that cause variable and reversible assembly of this essential cellular protein. Some of the polymeric properties of actin filaments will also be compared with filamentous bacteriophages, which are the most primitive self-replicating viruses. Both types of biopolymers have certain physical properties in common, and a better understanding of these simple systems shall help us to predict and manipulate their behavior, first in test tubes and then potentially in cellular and physiological conditions. Participating students will receive valuable training in applying physics concepts to biomaterials, and consequently acquire practical skills necessary to potentially succeed in a growing job market involving bioengineering and medical research in both academic institutions and the biotechnology industry. ***