Exploring the Self-Assembly Principle of Proteins for the Development of Bio-Hybrid Nanomaterials

Abstract

Protein self-assembly is a cornerstone of biological processes, vital for cellular function and with far-reaching applications in biotechnology, nanotechnology, and materials science. My research delves into the interplay between protein self-assembly, gene organization in operons, and the design of bio-nanohybrid materials for diverse applications. We first investigated how protein-protein interactions shape the genetic arrangement of the pdu operon in Salmonella enterica LT2, which encodes the 1,2 propanediol (Pdu) microcompartment. Using advanced quantitative spectroscopy tools, we mapped the interactions of the key shell protein PduA with other operonic proteins (PduBB’, PduJ, PduK, and PduN). Our findings revealed a strong correlation between the strength of these interactions and the sequential organization of their corresponding genes within the operon, providing insights into operonic evolution and functional assembly. Building on these insights, we explored the intrinsic self-assembling behavior of Pdu shell proteins, which naturally form 2D sheet structures featuring electron-dense and electron deficient surfaces. Harnessing this property, we demonstrated their semiconducting behavior and the ability to generate significant photocurrent under UV illumination. Through targeted mutagenesis, we confirmed that proton-coupled electron transfer (PCET) mechanisms underlie efficient electron transport in these systems, highlighting their potential as tunable, energy-efficient platforms for light-harvesting and semiconductor applications. In a parallel approach, we employed liquid-liquid phase separation (LLPS) to encapsulate protein-metal nanocomposites within liquid droplets, significantly enhancing catalytic activity by an order of magnitude. This dynamic system provides a versatile platform for developing highly efficient catalytic materials. Collectively, my research underscores the transformative potential of protein self-assembly and genetic engineering in developing functional biomaterials, paving the way for innovations in synthetic biology, nanotechnology, and next-generation electronic devices.