title: Recrystallized S-layer protein of a probiotic Propionibacterium: structural and nanomechanical changes upon temperature or pH shifts probed by solid-state NMR and AFM.
abstract: Surface protein layers (S layers) are common constituents of the bacterial cell wall and originate from the assembly of strain-dependent surface layer proteins (Slps). These proteins are thought to play important roles in the bacteria's biology and to have very promising technological applications as biomaterials or as part of cell-host cross-talk in probiotic mechanism. The SlpA from Propionibacterium freudenreichii PFCIRM 118 strain was isolated and recrystallized to investigate organization and assembly of the protein using atomic force microscopy and solid-state (1)H and (13)C-nuclear magnetic resonance. SlpA was found to form hexagonal p1 monolayer lattices where the protein exhibited high proportions of disordered regions and of bound water. The lattice structure was maintained, but softened, upon mild heating or acidification, probably in relation with the increasing mobilities of the disordered protein regions. These results gave structural insights on the mobile protein regions exposed by S layer films, upon physiologically relevant changes of their environmental conditions.
authors.affiliation: INRA-AGROCAMPUS OUEST UMR 1253 Science et Technologie du Lait et de l'Œuf, 35042 Rennes, France.
authors.forename: Paulo
authors.initials: P
authors.lastname: de sa Peixoto
authors.forename: Claire
authors.initials: C
authors.lastname: Roiland
authors.forename: Daniel
authors.initials: D
authors.lastname: Thomas
authors.forename: Valérie
authors.initials: V
authors.lastname: Briard-Bion
authors.forename: Rozenn
authors.initials: R
authors.lastname: Le Guellec
authors.forename: Sandrine
authors.initials: S
authors.lastname: Parayre
authors.forename: Stéphanie-Marie
authors.initials: SM
authors.lastname: Deutsch
authors.forename: Gwénaël
authors.initials: G
authors.lastname: Jan
authors.forename: Fanny
authors.initials: F
authors.lastname: Guyomarc'h
mesh_terms: D000595:Amino Acid Sequence; D019295:Computational Biology; D006863:Hydrogen-Ion Concentration; D008562:Membrane Glycoproteins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D019906:Nuclear Magnetic Resonance, Biomolecular; D019936:Probiotics; D011424:Propionibacterium / Q000737:chemistry*; D013696:Temperature
chemical_list: D008562:Membrane Glycoproteins; C055764:S-layer proteins