Phosphotriesterase: an enzyme in search of its natural substrate.
نویسندگان
چکیده
The bacterial PTE is able to catalyze the hydrolysis of a wide range of organophosphate nerve agents. The active site has been shown to consist of a unique binuclear metal center that has evolved to deliver hydroxide to the site of bond cleavage. The reaction rate for the hydrolysis of activated substrates such as paraoxon is limited by product release or an associated protein conformational change.
منابع مشابه
Crystal structure of VmoLac, a tentative quorum quenching lactonase from the extremophilic crenarchaeon Vulcanisaeta moutnovskia
A new representative of the Phosphotriesterase-Like Lactonases (PLLs) family from the hyperthermophilic crenarchaeon Vulcanisaeta moutnovskia has been characterized and crystallized. VmoLac is a native, proficient lactonase with promiscuous, low phosphotriesterase activity. VmoLac therefore represents an interesting candidate for engineering studies, with the aim of developing an efficient bact...
متن کاملThree-dimensional structure of phosphotriesterase: an enzyme capable of detoxifying organophosphate nerve agents.
Organophosphates, such as parathion and paraoxon, constitute the largest class of insecticides currently used in industrialized nations. In addition, many of these compounds are known to inhibit mammalian acetylcholinesterases thereby acting as nerve agents. Consequently, organophosphate-degrading enzymes are of considerable interest in light of their ability to detoxify such compounds. Here we...
متن کاملStereochemical constraints on the substrate specificity of phosphotriesterase.
A series of achiral, chiral, and racemic mixtures of paraoxon analogues containing various combinations of methyl, ethyl, isopropyl, or phenyl substituents were synthesized as probes of the stereochemical constraints within the active site of phosphotriesterase. The kinetic constants for these paraoxon analogues with the enzyme varied significantly with the size of substituents surrounding the ...
متن کاملActive Site Loop Conformation Regulates Promiscuous Activity in a Lactonase from Geobacillus kaustophilus HTA426
Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL) from Geobacillus kaustophilus HTA426 (GkaP) exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallo...
متن کاملPhosphorus-31 Nmr Relaxation Studies of Diethyl P- Methoxyphenyl Phosphate Bound to Phosphotriesterase
The effect of MnZ÷/Mn 2÷, Mn2÷/Zn 2÷ and ~VIn2+]Cd 2÷ reconstituted phosphotriesterase on the 3~p spin lattice (1/Tx) relaxation rate of diethyl p-methoxyphenyl phosphate has been investigated. In the presence of MnZ÷/Mn 2+ phosphotriesterase, the spin lattice relaxation rate of the phosphorus atom is enhanced giving an upper limit for the phosphorus-metal root mean-sixth average distance of 4....
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Advances in enzymology and related areas of molecular biology
دوره 74 شماره
صفحات -
تاریخ انتشار 2000