HAV-peptides attached to colloidal probes faithfully detect E-cadherins displayed on living cells.

Cell adhesion molecules are crucial for a variety of biological processes, including wound healing, barrier formationand tissue homeostasis. One of them is E-cadherin which is generally found at adherent junctions between epithelialcells. To identify this molecule on the surface of cells, E-cadherin mimetic peptides with a critical aminoacid sequence of HAV (histidine-alanine-valine) were synthesized and attached to solid supported membranes coveringcolloidal probes. Two different functionalization strategies were established, one based on complexation of DOGSNTA(Ni) with a polyhistidine-tagged HAV-peptide and the other one relying on the formation of a HAV-lipopeptide usingin situ maleimide-thiol coupling. Binding studies were performed to verify the ability of the peptides to attachto the membrane surface. Compared to the non-covalent attachment via the His-tag, we achieved a higher yield bylipopeptide formation. Colloidal probes functionalized with HAV-peptides were employed to measure the presence of Ecadherinson living cells either using video particle tracking or force spectroscopy. Here, human HaCaT cells were examinedconfirming the specific interaction of the HAV-peptide with the E-cadherin of the cells. Statistical methods werealso used to determine the number of single-bond ruptures and the force of a single bond. These findings may be essentialfor the development of novel biosynthetic materials given their potential to become increasingly relevant in medicalapplications.