Orientational Pathways during Protein Translocation through Polymer-Modified Nanopores

Estefania Gonzalez Solveyra, Yamila A. Perez Sirkin, Mario Tagliazucchi, Igal Szleifer*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Protein translocation through nanopores holds significant promise for applications in biotechnology, biomolecular analysis, and medicine. However, the interpretation of signals generated by the translocation of the protein remains challenging. In this way, it is crucial to gain a comprehensive understanding on how macromolecules translocate through a nanopore and to identify what are the critical parameters that govern the process. In this study, we investigate the interplay between protein charge regulation, orientation, and nanopore surface modifications using a theoretical framework that allows us to explicitly take into account the acid-base reactions of the titrable amino acids in the proteins and in the polyelectrolytes grafted to the nanopore surface. Our goal is to thoroughly characterize the translocation process of different proteins (GFP, β-lactoglobulin, lysozyme, and RNase) through nanopores modified with weak polyacids. Our calculations show that the charge regulation mechanism exerts a profound effect on the translocation process. The pH-dependent interactions between proteins and charged polymers within the nanopore lead to diverse free energy landscapes with barriers, wells, and flat regions dictating translocation efficiency. Comparison of different proteins allows us to identify the significance of protein isoelectric point, size, and morphology in the translocation behavior. Taking advantage of these insights, we propose pH-responsive nanopores that can load proteins at one pH and release them at another, offering opportunities for controlled protein delivery, separation, and sensing applications.

Original languageEnglish (US)
Pages (from-to)10427-10438
Number of pages12
JournalACS nano
Volume18
Issue number15
DOIs
StatePublished - Apr 16 2024

Funding

This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. E.G.S., Y.A.P.S., and M.T. are fellows of CONICET. This research was funded by grants PICT-2020-SERIEA-00188 (ANPCyT), PIBAA 2022-2023 28720210100765CO (CONICET), PICT 2019 1520, NSF EFMA-1830961, and NIH U54 CA268084.

Keywords

  • charge regulation
  • grafted polymers
  • nanopore
  • orientation
  • protein
  • theoretical methods
  • translocation

ASJC Scopus subject areas

  • General Materials Science
  • General Engineering
  • General Physics and Astronomy

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