The Adsorption of Amyloidogenic Peptides to Functionalized Surfaces Is Biased by Charge and Hydrophilicity

Torsten John, George W. Greene, Nitin A. Patil, Tiara J. A. Dealey, Mohammed A. Hossain, Bernd Abel, Lisandra L. Martin

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)

Abstract

The physicochemical properties of surfaces control the adsorption affinity of peptide molecules. Surfaces are abundant in living systems, such as in the form of cellular membranes, and govern many biological processes. Amyloidogenic peptides can form fibrillar aggregates and are associated with several age-related diseases such as Alzheimer's disease. They are abundant at low concentrations in organisms in their native, water-soluble form. In this study, the adsorption of the amyloidogenic model peptides GNNQQNY, NNFGAIL and VQIVYK as well as the amyloid-forming antimicrobial peptide uperin 3.5 (U3.5) have been studied at low concentrations on different biologically-relevant surfaces. The technique of a quartz crystal microbalance with dissipation monitoring (QCM-D) was applied as it enables the monitoring of mass binding to sensors at nanogram sensitivity. Gold-coated quartz sensors were used as unmodified gold surfaces or functionalized with self-assembled monolayers (SAMs) of functionalized alkanethiols (terminated as methyl, amino, carboxyl and hydroxyl) resulting in different adsorption affinities of the peptides. Our objective was to evaluate the underlying role of the nature and feature of interfaces in biological systems which could concentrate peptides and impact or trigger aggregation processes. Further, the glycoprotein lubricin (LUB) was tested as an antiadhesive coating towards these peptides. The adsorption of peptides at LUB coated sensors was, however, similar to the adsorption on unmodified gold surfaces, which indicates that the peptides diffused through the LUB layer to reach the underlying gold sensor surface. The LUB protein-antiadhesive is thus more effective as a biomaterial coating against larger biomolecules than small peptides under the conditions used here. This study provides directions towards amyloid peptide adsorption at biologically relevant interfaces, such as cellular membranes.

Original languageEnglish
Pages (from-to)14522-14531
Number of pages10
JournalLangmuir
Volume35
Issue number45
DOIs
Publication statusPublished - 12 Nov 2019

Keywords

  • adsorption
  • amyloid
  • binding
  • gold
  • interface
  • lubricin
  • peptide
  • SAM

Cite this