title: Atomic force microscopy imaging and single molecule recognition force spectroscopy of coat proteins on the surface of Bacillus subtilis spore.
abstract: Coat assembly in Bacillus subtilis serves as a tractable model for the study of the self-assembly process of biological structures and has a significant potential for use in nano-biotechnological applications. In the present study, the morphology of B. subtilis spores was investigated by magnetically driven dynamic force microscopy (MAC mode atomic force microscopy) under physiological conditions. B. subtilis spores appeared as prolate structures, with a length of 0.6-3 microm and a width of about 0.5-2 microm. The spore surface was mainly covered with bump-like structures with diameters ranging from 8 to 70 nm. Besides topographical explorations, single molecule recognition force spectroscopy (SMRFS) was used to characterize the spore coat protein CotA. This protein was specifically recognized by a polyclonal antibody directed against CotA (anti-CotA), the antibody being covalently tethered to the AFM tip via a polyethylene glycol linker. The unbinding force between CotA and anti-CotA was determined as 55 +/- 2 pN. From the high-binding probability of more than 20% in force-distance cycles it is concluded that CotA locates in the outer surface of B. subtilis spores.
authors.affiliation: Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria.
authors.forename: Jilin
authors.initials: J
authors.lastname: Tang
authors.forename: Daniela
authors.initials: D
authors.lastname: Krajcikova
authors.forename: Rong
authors.initials: R
authors.lastname: Zhu
authors.forename: Andreas
authors.initials: A
authors.lastname: Ebner
authors.forename: Simon
authors.initials: S
authors.lastname: Cutting
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Gruber
authors.forename: Imrich
authors.initials: I
authors.lastname: Barak
authors.forename: Peter
authors.initials: P
authors.lastname: Hinterdorfer
mesh_terms: D000906:Antibodies / Q000378:metabolism; D001412:Bacillus subtilis / Q000737:chemistry / Q000648:ultrastructure*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D018625:Microscopy, Atomic Force; D008954:Models, Biological; D011485:Protein Binding; D013057:Spectrum Analysis / Q000379:methods*; D013171:Spores, Bacterial / Q000648:ultrastructure*; D013499:Surface Properties
chemical_list: D000906:Antibodies; D001426:Bacterial Proteins