Mapping the Energy Landscape of Repetitive Structural Proteins

This final report covers our studies in the sequence-structure domain (initial funding) and its application in optical fibers (add-on funding). PART-I: Fibrous proteins' material properties and self-assembly behavior can be manipulated over a wide response range through variations in their repeat-unit amino-acid sequences. High-throughput screening of tandem-repeat libraries will enable the discovery of sequences with distinctive physical properties and improve our understanding of self-assembly, leading to revolutionary advances in materials and life sciences. We will test this hypothesis via two distinct but interrelated specific aims: Aim 1. Studying gene libraries of repetitive proteins using a label-free high-throughput technique Aim 2. Understanding the relationship between repetitive protein sequence and structure Aim 1. Studying gene libraries of repetitive proteins using a label-free high-throughput technique: We aim to produce repetitive protein libraries with precisely defined crystalline and amorphous regions. Using the crystalline domains of SRT sequences as templates (i.e., based on the considerable diversity of their variable AVSTH-rich domains), we propose constructing tandem-repeat gene libraries and analyzing the proteins they encode a high-throughput laser spectroscopy method. The sequence variation in our gene libraries will be based on (i) molecular weight (i.e., tandem-repeat number), (ii) amino acid content of the crystalline region, and (iii) the length ratio of the crystalline and amorphous domains. These parameters will directly affect crosslink and tie-chain densities of repetitive structural proteins, as shown in our preliminary data below. Task 1.1. Design and construct gene libraries by cloning and propagating repetitive sequences: Effective body temperature maintenance represents a critical component of the survival and success of military service members in combat and other hazardous environments.