title: Macromolecular assembly of Helicobacter pylori urease investigated by mass spectrometry.
abstract: The supramolecular assembly of Helicobacter pylori urease was studied by nanoflow electrospray ionization orthogonal time-of-flight mass spectrometry. The measured molecular mass of the urease complex of 1.06 MDa corresponds to a dodecameric (alphabeta)(12) assembly of urease alpha (26 kDa) and beta (61 kDa) subunits. The dodecamer disassembles readily into (alphabeta)(3) subunits in solution and under controlled collisional-induced dissociation in the gas phase. This is in strong support of an ((alphabeta)(3))(4) architecture consistent with the recently published x-ray structure. In vitro, the alpha and beta subunits are capable of re-assembling to (alphabeta)(3), but not further to the dodecameric complex.
authors.affiliation: Department of Biomolecular Mass Spectrometry, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands.
authors.forename: Martijn W H
authors.initials: MW
authors.lastname: Pinkse
authors.forename: Claudia S
authors.initials: CS
authors.lastname: Maier
authors.forename: Jung-In
authors.initials: JI
authors.lastname: Kim
authors.forename: Byung-Ha
authors.initials: BH
authors.lastname: Oh
authors.forename: Albert J R
authors.initials: AJ
authors.lastname: Heck
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli; D005838:Genotype; D016480:Helicobacter pylori / Q000201:enzymology*; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D017385:Sequence Homology; D021241:Spectrometry, Mass, Electrospray Ionization; D014510:Urease / Q000096:biosynthesis* / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D021122:Protein Subunits; D014510:Urease