Strength of multiple parallel biological bonds.
Multivalent interactions play a critical role in a variety of biological processes on both molecular and cellular levels. We have used molecular force spectroscopy to investigate the strength of multiple parallel peptide-antibody bonds using a system that allowed us to determine the rupture forces and the number of ruptured bonds independently. In our experiments the interacting molecules were attached to the surfaces of the probe and sample of the atomic force microscope with flexible polymer tethers, and the unique mechanical signatures of the tethers determined the number of ruptured bonds. We show that the rupture forces increase with the number of interacting molecules and that the measured forces obey the predictions of a Markovian model for the strength of multiple parallel bonds. We also discuss the implications of our results to the interpretation of force spectroscopy measurements in multiple bond systems.
Sulchek
Todd
T
Physical Biosciences Institute, Chemistry and Materials Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Friddle
Raymond W
RW
Noy
Aleksandr
A
D000906:Antibodies / Q000032:analysis* / Q000737:chemistry* / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000032:analysis / Q000737:chemistry*; D001665:Binding Sites; D003198:Computer Simulation; D018625:Microscopy, Atomic Force / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D018396:Mucin-1 / Q000032:analysis* / Q000737:chemistry* / Q000276:immunology; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry* / Q000276:immunology; D011485:Protein Binding
D000906:Antibodies; D000936:Antigen-Antibody Complex; C116055:MUC1 tandem repeat peptide; D018396:Mucin-1; D010446:Peptide Fragments