title: The interaction between OPH and paraoxon at the air-water interface studied by AFM and epifluorescence microscopies.
abstract: The paraoxon hydrolysis reaction catalyzed by organophosphorus hydrolase (OPH) monolayer at the air-water interface was studied. OPH-paraoxon interactions, occurring at the two-dimensional interface, by close-packed, highly orientated OPH monolayer, were investigated by several different surface chemistry techniques; e.g. surface pressure area isotherms, atomic force microscopy (AFM), and in situ epifluorescence microscopy. The characterization of OPH Langmuir and Langmuir-Blodgett films prepared in both the presence and absence of paraoxon, demonstrated significantly distinctive feature when compared with one another. Continuous growth of the OPH aggregates is a distinct phenomenon associated with hydrolysis, in addition to the pH changes in the local environment of the enzyme macromolecules.
authors.affiliation: Department of Chemistry, University of Miami, Coral Gables, FL 33124, USA.
authors.forename: Xihui
authors.initials: X
authors.lastname: Cao
authors.forename: Mustapha
authors.initials: M
authors.lastname: Mabrouki
authors.forename: Sarita V
authors.initials: SV
authors.lastname: Mello
authors.forename: Roger M
authors.initials: RM
authors.lastname: Leblanc
authors.forename: Vipin K
authors.initials: VK
authors.lastname: Rastogi
authors.forename: Tu-Chen
authors.initials: TC
authors.lastname: Cheng
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: DeFrank
mesh_terms: D000327:Adsorption; D000388:Air; D043303:Aryldialkylphosphatase / Q000737:chemistry*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008563:Membrane Lipids / Q000737:chemistry; D018625:Microscopy, Atomic Force / Q000379:methods; D010261:Paraoxon / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D008563:Membrane Lipids; D014867:Water; D043303:Aryldialkylphosphatase; D010261:Paraoxon