Eur. Phys. J. E 6, 273-276 (2001)

Specific biomembrane adhesion -Indirect lateral interactions between bound receptor molecules

C.W. Maier¹, A. Behrisch¹, A. Kloboucek¹, D.A. Simson¹ and R. Merkel<sup>2

1</sup>  Lehrstuhl für Biophysik, E22, Technische Universität München, 85748 Garching, Germany
²  Research Center Julich, Institute for Thin Films and Interfaces 4, 52425 Julich, Germany

r.merkel@fz-juelich.de

(Received 16 February 2001 )

Abstract
We studied biomembrane adhesion using the micropipet aspiration technique. Adhesion was caused by contact site A, a laterally mobile and highly specific cell adhesion molecule from Dictyostelium discoideum, reconstituted in lipid vesicles of DOPC (L--dioleoylphosphatidylcholine) with an addition of 5 mol % DOPE-PEG₂₀₀₀ (1,2-diacyl-sn-glycero-3-phosphatidylethanolamine-N-[poly(ethyleneglycol) 2000]). The "fuzzy" membrane mimics the cellular plasma membrane including the glycocalyx. We found adhesion and subsequent receptor migration into the contact zone. Using membrane tension jumps to probe the equation of state of the two-dimensional "gas" of bound receptor pairs within the contact zone, we found strong, attractive lateral interactions.

PACS
87.15.Kg - Molecular interactions; membrane-protein interactions.
87.16.Dg - Membranes, bilayers, and vesicles.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001