Quantification of Distributions of Local Proton Concentrations in Heterogeneous Soft Matter and Non-Anfinsen Biomacromolecules

• DOI: 10.1021/acs.jpclett.4c00825
• Publication Date: 2024-05-17T15:26:59Z
• Authors: Sergei Kuzin; Dario Stolba; Xiaowen Wu; Victoria N. Syrya...; Samy Boulos; Gunnar Jeschke; Laura Nyström; Maxim Yulikov
• Keywords: Soft matter

A new method to quantitatively analyze heterogeneous distributions of local proton densities around paramagnetic centers in unstructured and weakly structured biomacromolecules soft matter is introduced, its feasibility demonstrated on aqueous solutions stochastically spin-labeled polysaccharides. This based the pulse EPR experiment ih-RIDME (intermolecular hyperfine relaxation-induced dipolar modulation enhancement). Global analysis a series RIDME traces allows for mathematically stable transformation time-domain data distribution concentrations. Two sequences are proposed tested, which combine block double-electron–electron resonance (DEER) experiment. Such experiments can be potentially used correlate concentration with macromolecular chain conformation. We anticipate an application this approach studies intrinsically disordered proteins, biomolecular aggregates, condensates.