Molecular interaction between organophosphorus acid anhydrolase and diisopropylfluorophosphate.
Organophosphorus acid anhydrolases (OPAA; E.C.3.1.8.2) are a class of enzymes that hydrolyze a variety of toxic acetylcholinesterase-inhibiting organophosphorus (OP) compounds, including pesticides and fluorine-containing chemical nerve agents. In this paper, subphase conditions have been optimized to obtain stable OPAA Langmuir films, and the diisopropylfluorophosphate (DFP) hydrolysis reaction catalyzed by OPAA in aqueous solution and at the air-water interface was studied. OPAA-DFP interactions were investigated utilizing different spectroscopic techniques, that is, circular dichroism and fluorescence in aqueous solution and infrared reflection absorption spectroscopies at the air-water interface. The characterization of OPAA and its secondary structure in aqueous solution and as a monolayer at the air-water interface in the absence and in the presence of DFP dissolved in aqueous solution or in the aqueous subphase demonstrated significantly distinctive features. The research described herein demonstrated that OPAA can be used in an enzyme-based biosensor for DFP detection.
Zheng
Jiayin
J
Department of Chemistry, University of Miami, Coral Gables, Florida 33124-0431, USA.
Constantine
Celeste A
CA
Zhao
Liang
L
Rastogi
Vipin K
VK
Cheng
Tu-Chen
TC
Defrank
Joseph J
JJ
Leblanc
Roger M
RM
D043303:Aryldialkylphosphatase / Q000737:chemistry* / Q000378:metabolism*; D004347:Drug Interactions / Q000502:physiology; D006868:Hydrolysis; D007531:Isoflurophate / Q000737:chemistry* / Q000378:metabolism*; D013499:Surface Properties
D007531:Isoflurophate; D043303:Aryldialkylphosphatase