Interactions of a Polypeptide with a Protein Nanopore under Crowding Conditions

Motahareh Ghahari Larimi, Lauren Ashley Mayse, Liviu Movileanu

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Molecular crowding, a ubiquitous feature of the cellular environment, has significant implications in the kinetics and equilibrium of biopolymer interactions. In this study, a single charged polypeptide is exposed to competing forces that drive it into a transmembrane protein pore versus forces that pull it outside. Using single-molecule electrophysiology, we provide compelling experimental evidence that the kinetic details of the polypeptide-pore interactions are substantially affected by high concentrations of less-penetrating polyethylene glycols (PEGs). At a polymer concentration above a critical value, the presence of these neutral macromolecular crowders increases the rate constant of association but decreases the rate constant of dissociation, resulting in a stronger polypeptide-pore interaction. Moreover, a larger-molecular weight PEG exhibits a lower rate constant of association but a higher rate constant of dissociation than those values corresponding to a smaller-molecular weight PEG. These outcomes are in accord with a lower diffusion constant of the polypeptide and higher depletion-attraction forces between the polypeptide and transmembrane protein pore under crowding and confinement conditions.

Original languageEnglish (US)
Pages (from-to)4469-4477
Number of pages9
JournalACS Nano
Volume13
Issue number4
DOIs
StatePublished - Apr 23 2019

Fingerprint

crowding
Nanopores
Polypeptides
polypeptides
Rate constants
proteins
Proteins
Peptides
Polyethylene glycols
porosity
glycols
polyethylenes
Porins
interactions
molecular weight
Molecular weight
electrophysiology
Association reactions
dissociation
Electrophysiology

Keywords

  • free-energy landscape
  • peptide-protein interactions
  • polymer
  • single-channel electrical recordings
  • single-molecule kinetics
  • α-hemolysin

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Cite this

Interactions of a Polypeptide with a Protein Nanopore under Crowding Conditions. / Larimi, Motahareh Ghahari; Mayse, Lauren Ashley; Movileanu, Liviu.

In: ACS Nano, Vol. 13, No. 4, 23.04.2019, p. 4469-4477.

Research output: Contribution to journalArticle

Larimi, Motahareh Ghahari ; Mayse, Lauren Ashley ; Movileanu, Liviu. / Interactions of a Polypeptide with a Protein Nanopore under Crowding Conditions. In: ACS Nano. 2019 ; Vol. 13, No. 4. pp. 4469-4477.
@article{54ac6d7c05ab4dd4ac4db3db686a465b,
title = "Interactions of a Polypeptide with a Protein Nanopore under Crowding Conditions",
abstract = "Molecular crowding, a ubiquitous feature of the cellular environment, has significant implications in the kinetics and equilibrium of biopolymer interactions. In this study, a single charged polypeptide is exposed to competing forces that drive it into a transmembrane protein pore versus forces that pull it outside. Using single-molecule electrophysiology, we provide compelling experimental evidence that the kinetic details of the polypeptide-pore interactions are substantially affected by high concentrations of less-penetrating polyethylene glycols (PEGs). At a polymer concentration above a critical value, the presence of these neutral macromolecular crowders increases the rate constant of association but decreases the rate constant of dissociation, resulting in a stronger polypeptide-pore interaction. Moreover, a larger-molecular weight PEG exhibits a lower rate constant of association but a higher rate constant of dissociation than those values corresponding to a smaller-molecular weight PEG. These outcomes are in accord with a lower diffusion constant of the polypeptide and higher depletion-attraction forces between the polypeptide and transmembrane protein pore under crowding and confinement conditions.",
keywords = "free-energy landscape, peptide-protein interactions, polymer, single-channel electrical recordings, single-molecule kinetics, α-hemolysin",
author = "Larimi, {Motahareh Ghahari} and Mayse, {Lauren Ashley} and Liviu Movileanu",
year = "2019",
month = "4",
day = "23",
doi = "10.1021/acsnano.9b00008",
language = "English (US)",
volume = "13",
pages = "4469--4477",
journal = "ACS Nano",
issn = "1936-0851",
publisher = "American Chemical Society",
number = "4",

}

TY - JOUR

T1 - Interactions of a Polypeptide with a Protein Nanopore under Crowding Conditions

AU - Larimi, Motahareh Ghahari

AU - Mayse, Lauren Ashley

AU - Movileanu, Liviu

PY - 2019/4/23

Y1 - 2019/4/23

N2 - Molecular crowding, a ubiquitous feature of the cellular environment, has significant implications in the kinetics and equilibrium of biopolymer interactions. In this study, a single charged polypeptide is exposed to competing forces that drive it into a transmembrane protein pore versus forces that pull it outside. Using single-molecule electrophysiology, we provide compelling experimental evidence that the kinetic details of the polypeptide-pore interactions are substantially affected by high concentrations of less-penetrating polyethylene glycols (PEGs). At a polymer concentration above a critical value, the presence of these neutral macromolecular crowders increases the rate constant of association but decreases the rate constant of dissociation, resulting in a stronger polypeptide-pore interaction. Moreover, a larger-molecular weight PEG exhibits a lower rate constant of association but a higher rate constant of dissociation than those values corresponding to a smaller-molecular weight PEG. These outcomes are in accord with a lower diffusion constant of the polypeptide and higher depletion-attraction forces between the polypeptide and transmembrane protein pore under crowding and confinement conditions.

AB - Molecular crowding, a ubiquitous feature of the cellular environment, has significant implications in the kinetics and equilibrium of biopolymer interactions. In this study, a single charged polypeptide is exposed to competing forces that drive it into a transmembrane protein pore versus forces that pull it outside. Using single-molecule electrophysiology, we provide compelling experimental evidence that the kinetic details of the polypeptide-pore interactions are substantially affected by high concentrations of less-penetrating polyethylene glycols (PEGs). At a polymer concentration above a critical value, the presence of these neutral macromolecular crowders increases the rate constant of association but decreases the rate constant of dissociation, resulting in a stronger polypeptide-pore interaction. Moreover, a larger-molecular weight PEG exhibits a lower rate constant of association but a higher rate constant of dissociation than those values corresponding to a smaller-molecular weight PEG. These outcomes are in accord with a lower diffusion constant of the polypeptide and higher depletion-attraction forces between the polypeptide and transmembrane protein pore under crowding and confinement conditions.

KW - free-energy landscape

KW - peptide-protein interactions

KW - polymer

KW - single-channel electrical recordings

KW - single-molecule kinetics

KW - α-hemolysin

UR - http://www.scopus.com/inward/record.url?scp=85065343741&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85065343741&partnerID=8YFLogxK

U2 - 10.1021/acsnano.9b00008

DO - 10.1021/acsnano.9b00008

M3 - Article

VL - 13

SP - 4469

EP - 4477

JO - ACS Nano

JF - ACS Nano

SN - 1936-0851

IS - 4

ER -