title: Reference-free alignment and sorting of single-molecule force spectroscopy data.
abstract: Single-molecule force spectroscopy has become a versatile tool for investigating the (un)folding of proteins and other polymeric molecules. Like other single-molecule techniques, single-molecule force spectroscopy requires recording and analysis of large data sets to extract statistically meaningful conclusions. Here, we present a data analysis tool that provides efficient filtering of heterogeneous data sets, brings spectra into register based on a reference-free alignment algorithm, and determines automatically the location of unfolding barriers. Furthermore, it groups spectra according to the number of unfolding events, subclassifies the spectra using cross correlation-based sorting, and extracts unfolding pathways by principal component analysis and clustering methods to extracted peak positions. Our approach has been tested on a data set obtained through mechanical unfolding of bacteriorhodopsin (bR), which contained a significant number of spectra that did not show the well-known bR fingerprint. In addition, we have tested the performance of the data analysis tool on unfolding data of the soluble multidomain (Ig27)(8) protein.
authors: Department for Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.
authors: Patrick D
authors: PD
authors: Bosshart
authors: Patrick L T M
authors: PL
authors: Frederix
authors: Andreas
authors: A
authors: Engel
mesh_terms: D000465:Algorithms; D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000648:ultrastructure*; D003198:Computer Simulation; D018625:Microscopy, Atomic Force / Q000379:methods*; D008958:Models, Molecular; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000737:chemistry*; D012016:Reference Values
chemical_list: D015335:Molecular Probes; D001436:Bacteriorhodopsins