• Home
  • Search Results
  • Bimolecular integrin-ligand interactions quantified using peptide-functionalized dextran-coated microparticles.

Bimolecular integrin-ligand interactions quantified using peptide-functionalized dextran-coated microparticles.

Integrative biology : quantitative biosciences from nano to macro (2011-11-29)
Jessie E P Sun, Justin Vranic, Russell J Composto, Craig Streu, Paul C Billings, Joel S Bennett, John W Weisel, Rustem I Litvinov
ABSTRACT

Integrins play a key role in cell-cell and cell-matrix interactions. Artificial surfaces grafted with integrin ligands, mimicking natural interfaces, have been used to study integrin-mediated cell adhesion. Here we report the use of a new chemical engineering technology in combination with single-molecule nanomechanical measurements to quantify peptide binding to integrins. We prepared latex beads with covalently-attached dextran. The beads were then functionalized with the bioactive peptides, cyclic RGDFK (cRGD) and the fibrinogen γC-dodecapeptide (H12), corresponding to the active sites for fibrinogen binding to the platelet integrin αIIbβ3. Using optical tweezers-based force spectroscopy to measure non-specific protein-protein interactions, we found the dextran-coated beads nonreactive towards fibrinogen, thus providing an inert platform for biospecific modifications. Using periodate oxidation followed by reductive amination, we functionalized the bead-attached dextran with either cRGD or H12 and used the peptide-grafted beads to measure single-molecule interactions with the purified αIIbβ3. Bimolecular force spectroscopy revealed that the peptide-functionalized beads were highly and specifically reactive with the immobilized αIIbβ3. Further, the cRGD- and H12-functionalized beads displayed a remarkable interaction profile with a bimodal force distribution up to 90 pN. The cRGD-αIIbβ3 interactions had greater binding strength than that of H12-αIIbβ3, indicating that they are more stable and resistant mechanically, consistent with the platelet reactivity of RGD-containing ligands. Thus, the results reported here describe the mechanistic characteristics of αIIbβ3-ligand interactions, confirming the utility of peptide-functionalized latex beads for the quantitative analysis of molecular recognition.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Micro particles based on polystyrene, size: 100 nm

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

MilliporeSigma

Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.