title: Molecular force spectroscopy of homophilic nectin-1 interactions.
abstract: Nectins are Ca2+ independent cell adhesion molecules localizing at the cadherin based adherens junctions. In this study, we have used atomic force microscopy to study interaction of a chimera of extra cellular fragment of nectin-1 and Fc of human IgG (nef-1) with wild type L-fibroblasts that express endogenous nectin-1 to elucidate the biophysical characteristics of homophilic nectin-1 trans-interactions at the level of single molecule. Bond strength distribution revealed three distinct bound states (or configurations) of trans-interactions between paired nectins, where each bound state has a unique unstressed off-rate and reactive compliance. Kinetic analysis of force-dependent off-rate of the bound state involving trans-interacting V-V domains between paired nectin-1 (unstressed off-rate approximately 1.465+/-0.779 s(-1), reactive compliance approximately 0.143+/-0.072 nm) was found to be closest to E-cadherin, indicating that V-V domain trans-interactions are probably necessary to initiate and promote adhesions of E-cadherin at adherens junctions (AJs).
authors.affiliation: Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore.
authors.forename: Sri Ram Krishna
authors.initials: SR
authors.lastname: Vedula
authors.forename: Tong Seng
authors.initials: TS
authors.lastname: Lim
authors.forename: Shi
authors.initials: S
authors.lastname: Hui
authors.forename: P Jaya
authors.initials: PJ
authors.lastname: Kausalya
authors.forename: E Birgitte
authors.initials: EB
authors.lastname: Lane
authors.forename: Gunaretnam
authors.initials: G
authors.lastname: Rajagopal
authors.forename: Walter
authors.initials: W
authors.lastname: Hunziker
authors.forename: Chwee Teck
authors.initials: CT
authors.lastname: Lim
mesh_terms: D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D005347:Fibroblasts / Q000378:metabolism*; D018625:Microscopy, Atomic Force / Q000379:methods*; D000075983:Nectins; D011485:Protein Binding; D015728:Receptors, HIV / Q000378:metabolism*; D013314:Stress, Mechanical