Steering protein adsorption at charged surfaces: electric fields and ionic screening

Mulheran, Paul A.; Connell, David J.; Kubiak-Ossowska, Karina

doi:10.1039/c6ra16391b

Cited by 23 publications

(40 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is known that the presence of salt can affect protein-protein and protein-substrate interactions through electrostatic shielding effects [ 56 , 73 ]. In addition, protein conformation can also be stabilized by the presence of salt [ 74 , 75 , 76 , 77 ].…”

Section: Resultsmentioning

confidence: 99%

“…This allowed us to highlight the effect of subtle differences in surface properties on protein adsorption behavior. Furthermore, by varying the ionic strength condition, it was possible to tune the protein-substrate interaction, especially via charge shielding of electrostatic forces [ 53 , 54 , 55 , 56 , 57 ]. In turn, this enabled us to establish an analytical framework to quantitatively compare responses across multiple substrates with different sensitivities and demonstrate the capability of the nanoplasmonic sensing technique to identify unique patterns of protein adsorption and denaturation on different surfaces, paving the way for its utilization across various application settings.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Quantitative Comparison of Protein Adsorption and Conformational Changes on Dielectric-Coated Nanoplasmonic Sensing Arrays

Ferhan

Jackman

Sut

et al. 2018

Sensors

View full text Add to dashboard Cite

Nanoplasmonic sensors are a popular, surface-sensitive measurement tool to investigate biomacromolecular interactions at solid-liquid interfaces, opening the door to a wide range of applications. In addition to high surface sensitivity, nanoplasmonic sensors have versatile surface chemistry options as plasmonic metal nanoparticles can be coated with thin dielectric layers. Within this scope, nanoplasmonic sensors have demonstrated promise for tracking protein adsorption and substrate-induced conformational changes on oxide film-coated arrays, although existing studies have been limited to single substrates. Herein, we investigated human serum albumin (HSA) adsorption onto silica- and titania-coated arrays of plasmonic gold nanodisks by localized surface plasmon resonance (LSPR) measurements and established an analytical framework to compare responses across multiple substrates with different sensitivities. While similar responses were recorded on the two substrates for HSA adsorption under physiologically-relevant ionic strength conditions, distinct substrate-specific behavior was observed at lower ionic strength conditions. With decreasing ionic strength, larger measurement responses occurred for HSA adsorption onto silica surfaces, whereas HSA adsorption onto titania surfaces occurred independently of ionic strength condition. Complementary quartz crystal microbalance-dissipation (QCM-D) measurements were also performed, and the trend in adsorption behavior was similar. Of note, the magnitudes of the ionic strength-dependent LSPR and QCM-D measurement responses varied, and are discussed with respect to the measurement principle and surface sensitivity of each technique. Taken together, our findings demonstrate how the high surface sensitivity of nanoplasmonic sensors can be applied to quantitatively characterize protein adsorption across multiple surfaces, and outline broadly-applicable measurement strategies for biointerfacial science applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Quantitative Comparison of Protein Adsorption and Conformational Changes on Dielectric-Coated Nanoplasmonic Sensing Arrays

Ferhan

Jackman

Sut

et al. 2018

Sensors

View full text Add to dashboard Cite

show abstract

“…Since the surface field was screened by the counter ions in solution, the adsorption was relatively slow, occurring on a 10 ns timescale in the simulations. This allowed the peptide time to diffuse above the surface and find its preferred orientation before adsorption, a process described elsewhere 22 , 29 . When the peptide adsorbed, it was steered by Arg8, whose positive side-chain extended towards the negatively charged surface.…”

Section: Resultsmentioning

confidence: 99%

“…For example, model silica surfaces have been used to understand and interpret experimental lysozyme adsorption 23 , as well as the functionalisation of SiNPs with cell penetrating peptides 22 . In this work we used our simulation approach 29 to investigate how the GnRH-I and cys-GnRH-I peptides interact with the model silica surface. We also simulated the behaviour of cys-GnRH-I covalently bonded to the surface of the carrier protein bovine serum albumin (BSA).…”

Section: Introductionmentioning

confidence: 99%

Rationalising drug delivery using nanoparticles: a combined simulation and immunology study of GnRH adsorbed to silica nanoparticles

Connell

Gebril

Khan

et al. 2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

Silica nanoparticles (SiNPs) have been shown to have significant potential for drug delivery and as adjuvants for vaccines. We have simulated the adsorption of GnRH-I (gonadotrophin releasing hormone I) and a cysteine-tagged modification (cys-GnRH-I) to model silica surfaces, as well as its conjugation to the widely-used carrier protein bovine serum albumin (BSA). Our subsequent immunological studies revealed no significant antibody production was caused by the peptide-SiNP systems, indicating that the treatment was not effective. However, the testosterone response with the native peptide-SiNPs indicated a drug effect not found with cys-GnRH-I-SiNPs; this behaviour is explained by the specific orientation of the peptides at the silica surface found in the simulations. With the BSA systems, we found significant testosterone reduction, particularly for the BSA-native conjugates, and an antibody response that was notably higher with the SiNPs acting as an adjuvant; this behaviour again correlates well with the epitope presentation predicted by the simulations. The range of immunological and hormone response can therefore be interpreted and understood by the simulation results and the presentation of the peptides to solution, paving the way for the future rational design of drug delivery and vaccine systems guided by biomolecular simulation.

show abstract

“…[4][5][6][7][8][9] Protein adsorption is well known to be dependent on environmental factors, for example pH, ionic strength, and also physicochemical properties of the protein and surface. 4,7,10 Studies concerning protein adsorption onto charged substrates show that the major driving forces are electrostatic and hydrophobic interactions; 3,5,[11][12][13] these govern the specific orientation and the structure of the proteins in the adsorbed layers. As well as quantifying molecular orientation, conformation or aggregation of adsorbed protein, it is also important to quantify dynamic phenomena such as surface diffusion, which can affect the surface excess density.…”

Section: Introductionmentioning

confidence: 99%

Energy Landscape of Negatively Charged BSA Adsorbed on a Negatively Charged Silica Surface

et al. 2018

Self Cite

View full text Add to dashboard Cite

We study the energy landscape of the negatively charged protein bovine serum albumin adsorbed on a negatively charged silica surface at pH 7. We use fully atomistic molecular dynamics (MD) and steered MD (SMD) to probe the energy of adsorption and the pathway for the surface diffusion of the protein and its associated activation energy. We find an adsorption energy ∼1.2 eV, which implies that adsorption is irreversible even on experimental time scales of hours. In contrast, the activation energy for surface diffusion is ∼0.4 eV so that it is observable on the MD simulation time scale of 100 ns. This analysis paves the way for a more detailed understanding of how a protein layer forms on biomaterial surfaces, even when the protein and surface share the same electrical polarity.

show abstract

Steering protein adsorption at charged surfaces: electric fields and ionic screening

Abstract: Protein adsorption at charged surfaces is a common process in the development of functional technological devices.

Cited by 23 publications

References 43 publications

Quantitative Comparison of Protein Adsorption and Conformational Changes on Dielectric-Coated Nanoplasmonic Sensing Arrays

Quantitative Comparison of Protein Adsorption and Conformational Changes on Dielectric-Coated Nanoplasmonic Sensing Arrays

Rationalising drug delivery using nanoparticles: a combined simulation and immunology study of GnRH adsorbed to silica nanoparticles

Energy Landscape of Negatively Charged BSA Adsorbed on a Negatively Charged Silica Surface

Contact Info

Product

Resources

About