Molecular force spectroscopy of homophilic nectin-1 interactions

• Published in: Biochemical and biophysical research communications 2007-11, Vol.362 (4), p.886-892
• Main Authors: Vedula, Sri Ram Krishna, Lim, Tong Seng, Hui, Shi, Kausalya, P. Jaya, Lane, E. Birgitte, Rajagopal, Gunaretnam, Hunziker, Walter, Lim, Chwee Teck
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; ATOMIC FORCE MICROSCOPY; BOUND STATE; CALCIUM IONS; Cell adhesion; Cell Adhesion Molecules - metabolism; Cell Line; CHIMERAS; CONFIGURATION MIXING; FIBROBLASTS; Fibroblasts - metabolism; Microscopy, Atomic Force - methods; MOLECULES; Nectins; Protein Binding; Receptors, HIV - metabolism; Single-molecule force spectroscopy; SPECTROSCOPY; Stress, Mechanical; SULFUR IONS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2007.08.096

Nectins are Ca 2+ 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 ∼1.465 ± 0.779 s −1, reactive compliance ∼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).