AVS 47th International Symposium
    Biomaterial Interfaces Thursday Sessions
       Session BI+NS-ThM

Paper BI+NS-ThM4
Unbinding Process of Adsorbed Proteins under External Stress Studied by AFM Force Spectroscopy

Thursday, October 5, 2000, 9:20 am, Room 202

Session: Nanoscale Biology
Presenter: J. Voegel, INSERM, France
Authors: C. Gergely, INSERM, France
J. Voegel, INSERM, France
P. Schaaf, Institut Charles Sadron (CNRS) Strasbourg, France
B. Senger, INSERM, France
J.K.H. Horber, EMBL Heidelberg, Germany
J. Hemmerle, INSERM, France
Correspondent: Click to Email
We report the study of the unbinding process under a force load f of adsorbed proteins (fibrinogen) on a solid surface (hydrophilic silica) by means of AFM force spectroscopy. By varying the loading rate r, defined by f=r.t, t being the time, we find that, as for specific interactions, the mean rupture force increases with r. This unbinding process is analysed in the framework of the widely used Bell model. Thus typical dissociation rate at zero force entering in the model lies between 0.02 and 0.6 1/s. Each measured rupture is characterized by a force f0 which appears to be quantized in integer multiples of 180-200 pN.