Literature summary for 3.1.8.1 extracted from

Grimsley, J.K.; Calamini, B.; Wild, J.R.; Mesecar, A.D.
Structural and mutational studies of organophosphorus hydrolase reveal a cryptic and functional allosteric-binding site (2005), Arch. Biochem. Biophys., 442, 169-179.

Application

Application	Comment	Organism
environmental protection	the enzyme is involved in detoxification of organophosphorus pesticides and chemical warfare agents sarin and VX	Brevundimonas diminuta

Cloned(Commentary)

Cloned (Comment)	Organism
expression of mutant enzyme	Brevundimonas diminuta

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified recombinant mutant enzyme H254R bound to inhibitor diethyl 4-methylbenzylphosphonate, 5.8 mg/ml protein in 20 mM HEPES, pH 7.5, hanging drop vapour diffusion method, room temperature, the precipitation solution contains 9% PEG 6000, 100 mM CHES, pH 9.0, 1% diethyl 4-methylbenzylphosphonate, and 5 mM sodium azide, no Co2+ is added, X-ray diffraction structure determination and analysis at 1.9 A resolution	Brevundimonas diminuta

Crystallization (Comment)

Organism

purified recombinant mutant enzyme H254R bound to inhibitor diethyl 4-methylbenzylphosphonate, 5.8 mg/ml protein in 20 mM HEPES, pH 7.5, hanging drop vapour diffusion method, room temperature, the precipitation solution contains 9% PEG 6000, 100 mM CHES, pH 9.0, 1% diethyl 4-methylbenzylphosphonate, and 5 mM sodium azide, no Co2+ is added, X-ray diffraction structure determination and analysis at 1.9 A resolution

Brevundimonas diminuta

Protein Variants

Protein Variants	Comment	Organism
H254R	site-directed mutagenesis, the mutation increases the mutants activity with substrate demeton-S, a VX analogue, 4fold and decreases the activity with paraoxon 14fold as well as activity towards diisopropyl phosphorofluoridate, a sarin analogue, 183fold compared to the wild-type enzyme	Brevundimonas diminuta

Inhibitors

Inhibitors	Comment	Organism	Structure
diethyl 4-methylbenzylphosphonate	the inhibitor does not bind at the active site, but binds exclusively into a well-defined surface pocket 12 A away from the active site, docking, overview	Brevundimonas diminuta

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism
additional information	-	additional information	kinetic evaluation, mutant H254R	Brevundimonas diminuta
0.012	-	paraoxon	mutant H254R, pH 9.0, 25°C	Brevundimonas diminuta
0.12	-	paraoxon	wild-type enzyme, pH 9.0, 25°C	Brevundimonas diminuta

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Co2+	binuclear metalloenzyme	Brevundimonas diminuta

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
additional information	Brevundimonas diminuta	the enzyme is involved in detoxification of a broad range of organophosphorus pesticides and chemical warfare agents sarin and VX	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Brevundimonas diminuta	P0A434	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant mutant enzyme	Brevundimonas diminuta

Reaction

Reaction	Comment	Organism	Reaction ID
an aryl dialkyl phosphate + H2O = dialkyl phosphate + an aryl alcohol	catalytic mechanism and active site structure, substrate docking mechanism	Brevundimonas diminuta	a

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
additional information	-	-	Brevundimonas diminuta

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
additional information	the enzyme is involved in detoxification of a broad range of organophosphorus pesticides and chemical warfare agents sarin and VX	Brevundimonas diminuta	?	-	?
paraoxon + H2O	-	Brevundimonas diminuta	4-nitrophenol + diethyl phosphate	-	?

Subunits

Subunits	Comment	Organism
monomer	three-dimensional structure analysis	Brevundimonas diminuta

Synonyms

Synonyms	Comment	Organism
OPH	-	Brevundimonas diminuta
organophosphorus hydrolase	-	Brevundimonas diminuta

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
25	-	assay at	Brevundimonas diminuta

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
750	-	paraoxon	mutant H254R, pH 9.0, 25°C	Brevundimonas diminuta
10500	-	paraoxon	wild-type enzyme, pH 9.0, 25°C	Brevundimonas diminuta

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
9	-	assay at	Brevundimonas diminuta

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
0.25	-	diethyl 4-methylbenzylphosphonate	mutant H254R, pH 9.0, 25°C, versus paraoxon	Brevundimonas diminuta
0.99	-	diethyl 4-methylbenzylphosphonate	wild-type enzyme, pH 9.0, 25°C, versus paraoxon	Brevundimonas diminuta