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Accurate Correction of the "bulk Response" in Surface Plasmon Resonance Sensing Provides New Insights on Interactions Involving Lysozyme and Poly(ethylene glycol)

Svirelis, Justas ; Andersson, John ; Stradner, Anna LU and Dahlin, Andreas (2022) In ACS Sensors 7(4). p.1175-1182
Abstract

Surface plasmon resonance is a very well-established surface sensitive technique for label-free analysis of biomolecular interactions, generating thousands of publications each year. An inconvenient effect that complicates interpretation of SPR results is the "bulk response" from molecules in solution, which generate signals without really binding to the surface. Here we present a physical model for determining the bulk response contribution and verify its accuracy. Our method does not require a reference channel or a separate surface region. We show that proper subtraction of the bulk response reveals an interaction between poly(ethylene glycol) brushes and the protein lysozyme at physiological conditions. Importantly, we also show... (More)

Surface plasmon resonance is a very well-established surface sensitive technique for label-free analysis of biomolecular interactions, generating thousands of publications each year. An inconvenient effect that complicates interpretation of SPR results is the "bulk response" from molecules in solution, which generate signals without really binding to the surface. Here we present a physical model for determining the bulk response contribution and verify its accuracy. Our method does not require a reference channel or a separate surface region. We show that proper subtraction of the bulk response reveals an interaction between poly(ethylene glycol) brushes and the protein lysozyme at physiological conditions. Importantly, we also show that the bulk response correction method implemented in commercial instruments is not generally accurate. Using our method, the equilibrium affinity between polymer and protein is determined to be KD= 200 μM. One reason for the weak affinity is that the interaction is relatively short-lived (1/koff< 30 s). Furthermore, we show that the bulk response correction also reveals the dynamics of self-interactions between lysozyme molecules on surfaces. Besides providing new insights on important biomolecular interactions, our method can be widely applied to improve the accuracy of SPR data generated by instruments worldwide.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
kinetics, lysozyme, poly(ethylene glycol), quantification, surface plasmon resonance
in
ACS Sensors
volume
7
issue
4
pages
8 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:35298135
  • scopus:85127921489
ISSN
2379-3694
DOI
10.1021/acssensors.2c00273
language
English
LU publication?
yes
id
c06c3563-d1b2-4f5f-baae-c635bd985a89
date added to LUP
2022-06-17 14:18:03
date last changed
2024-06-27 19:03:09
@article{c06c3563-d1b2-4f5f-baae-c635bd985a89,
  abstract     = {{<p>Surface plasmon resonance is a very well-established surface sensitive technique for label-free analysis of biomolecular interactions, generating thousands of publications each year. An inconvenient effect that complicates interpretation of SPR results is the "bulk response" from molecules in solution, which generate signals without really binding to the surface. Here we present a physical model for determining the bulk response contribution and verify its accuracy. Our method does not require a reference channel or a separate surface region. We show that proper subtraction of the bulk response reveals an interaction between poly(ethylene glycol) brushes and the protein lysozyme at physiological conditions. Importantly, we also show that the bulk response correction method implemented in commercial instruments is not generally accurate. Using our method, the equilibrium affinity between polymer and protein is determined to be K<sub>D</sub>= 200 μM. One reason for the weak affinity is that the interaction is relatively short-lived (1/k<sub>off</sub>&lt; 30 s). Furthermore, we show that the bulk response correction also reveals the dynamics of self-interactions between lysozyme molecules on surfaces. Besides providing new insights on important biomolecular interactions, our method can be widely applied to improve the accuracy of SPR data generated by instruments worldwide.</p>}},
  author       = {{Svirelis, Justas and Andersson, John and Stradner, Anna and Dahlin, Andreas}},
  issn         = {{2379-3694}},
  keywords     = {{kinetics; lysozyme; poly(ethylene glycol); quantification; surface plasmon resonance}},
  language     = {{eng}},
  number       = {{4}},
  pages        = {{1175--1182}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Sensors}},
  title        = {{Accurate Correction of the "bulk Response" in Surface Plasmon Resonance Sensing Provides New Insights on Interactions Involving Lysozyme and Poly(ethylene glycol)}},
  url          = {{http://dx.doi.org/10.1021/acssensors.2c00273}},
  doi          = {{10.1021/acssensors.2c00273}},
  volume       = {{7}},
  year         = {{2022}},
}