A Structure-Guided Design of Two-Dimensional Self-Assembling Proteins from Hydrophobins and Hexameric Coiled Coils

Ionomer membranes are widely used in fuel cells due to their superior mechanical and ion transport properties. The morphology within these membranes dictates the ion transport through their ionomer hydrophilic channels. Ongoing experiments are focused on understanding structure of ionomer hydrophilic domains and how it changes with extents of hydration and different processing techniques. In this regard, small angle scattering (SAS) measurements are helpful in characterizing their internal structure at multiple length scales. In this poster we present our recent development and user of two complementary computational approaches for analysis of SAS profiles to interpret the structure of ionomer membranes. In the first approach, we analyze SAS profiles using CREASE (Computational Reverse Engineering Analysis for Scattering Experiments) [1, 2] with structures generated by CASGAP [3]; this allows us to identify shapes and sizes of domains that give rise to the SAS profile. In the second complementary approach, we use coarse-grained molecular dynamics simulations with MARTINI 2 model to represent the ionomers and polarizable water model to represent water molecules to understand the molecular packing within ionomer hydrophilic domains; this allows us to explain how the polymer design and extent of hydration drives the domain sizes and shapes that show up as features in the SAS profiles.

[1] Nitant Gupta, Arthi Jayaraman, “Computational Approach for Structure Generation of Anisotropic Particles (CASGAP) with Targeted Distributions of Particle Design and Orientational Order” submitted for peer review in April 2023

[2]Christian M. Heil, Anvay Patil, Ali Dhinojwala, Arthi Jayaraman, Computational Reverse-Engineering Analysis for Scattering Experiments (CREASE) with Machine Learning Enhancement to Determine Structure of Nanoparticle Mixtures and Solutions. ACS Cent. Sci. 2022, 8, 996– 1007

[3] Christian M. Heil, Yingzhen Ma, Bhuvnesh Bharti, and Arthi Jayaraman, Computational Reverse-Engineering Analysis for Scattering Experiments for Form Factor and Structure Factor Determination (“P(q) and S(q) CREASE”) JACS Au 2023, 3, 3, 889–904