Preliminary time-of-flight neutron diffraction study on diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris.
The enzyme diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris is capable of decontaminating a wide variety of toxic organophosphorus nerve agents. DFPase is structurally related to a number of enzymes, such as the medically important paraoxonase (PON). In order to investigate the reaction mechanism of this phosphotriesterase and to elucidate the protonation state of the active-site residues, large-sized crystals of DFPase have been prepared for neutron diffraction studies. Available H atoms have been exchanged through vapour diffusion against D2O-containing mother liquor in the capillary. A neutron data set has been collected to 2.2 A resolution on a relatively small (0.43 mm3) crystal at the spallation source in Los Alamos. The sample size and asymmetric unit requirements for the feasibility of neutron diffraction studies are summarized.
Blum
Marc-Michael
MM
Institute of Biophysical Chemistry, J. W. Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany.
Koglin
Alexander
A
Rüterjans
Heinz
H
Schoenborn
Benno
B
Langan
Paul
P
Chen
Julian C-H
JC
D000818:Animals; D005240:Feasibility Studies; D049834:Loligo / Q000737:chemistry / Q000201:enzymology*; D033363:Neutron Diffraction / Q000379:methods*; D044345:Phosphoric Triester Hydrolases / Q000737:chemistry* / Q000302:isolation & purification
D044345:Phosphoric Triester Hydrolases; C020061:diisopropyl-fluorophosphatase