title: Transition model for ricin-aptamer interactions with multiple pathways and energy barriers.
abstract: We develop a transition model to interpret single-molecule ricin-aptamer interactions with multiple unbinding pathways and energy barriers measured by atomic force microscopy dynamic force spectroscopy. Molecular simulations establish the relationship between binding conformations and the corresponding unbinding pathways. Each unbinding pathway follows a Bell-Evans multiple-barrier model. Markov-type transition matrices are developed to analyze the redistribution of unbinding events among the pathways under different loading rates. Our study provides detailed information about complex behaviors in ricin-aptamer unbinding events.
authors.affiliation: Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: Bingqian
authors.initials: B
authors.lastname: Xu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001665:Binding Sites; D003198:Computer Simulation; D004735:Energy Transfer; D004789:Enzyme Activation; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D008958:Models, Molecular; D044367:Phase Transition; D011485:Protein Binding; D011487:Protein Conformation; D012276:Ricin / Q000737:chemistry* / Q000648:ultrastructure*; D013314:Stress, Mechanical; D013379:Substrate Specificity
chemical_list: D052157:Aptamers, Nucleotide; D012276:Ricin