Single molecular dynamic interactions between glycophorin A and lectin as probed by atomic force microscopy.
Glycophorin A (GpA) is one of the most abundant transmembrane proteins in human erythrocytes and its interaction with lectins has been studied as model systems for erythrocyte related biological processes. We performed a force measurement study using the force mode of atomic force microscopy (AFM) to investigate the single molecular level biophysical mechanisms involved in GpA-lectin interactions. GpA was mounted on a mica surface or natively presented on the erythrocyte membrane and probed with an AFM tip coated with the monomeric but multivalent Psathyrella velutina lectin (PVL) through covalent crosslinkers. A dynamic force spectroscopy study revealed similar interaction properties in both cases, with the unbinding force centering around 60 pN with a weak loading rate dependence. Hence we identified the presence of one energy barrier in the unbinding process. Force profile analysis showed that more than 70% of GpAs are free of cytoskeletal associations in agreement with previous reports.
Yan
Chao
C
Laboratory of Biodynamics, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
Yersin
Alexandre
A
Afrin
Rehana
R
Sekiguchi
Hiroshi
H
Ikai
Atsushi
A
D006021:Glycophorins / Q000737:chemistry*; D006801:Humans; D037102:Lectins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs
D006021:Glycophorins; D037102:Lectins