Cholinesterase for Prophylactics of Poisoning by Organophosphorous Inhibitors
The Production of Highly Active Human Blood Plasma Butyrylcholinesterase Preparation by Gene Engineering Methods to Create Protective Means against Poisoning by Organophosphorous Cholinesterase Inhibitors
Tech Area / Field
- MED-DRG/Drug Discovery/Medicine
- BIO-CGM/Cytology, Genetics and Molecular Biology/Biotechnology
8 Project completed
Senior Project Manager
Safronova O N
State Research Institute of Organic Chemistry and Technology, Russia, Moscow
- State Scientific Center of Genetics and Selection of Industrial Microorganisms (GosNIIGenetica), Russia, Moscow
- Laboratory of neurobiology, France, Paris
Project summaryAt the present time, the antidote therapy in poisonings by organophosphorous (OP) cholinesterase inhibitors remains a very burning problem in view of the wide application of these substances in household, industry, agriculture and the existing potential threat of using OP inhibitors as chemical weapons for military and terroristic attacks and other incidents. This problem is of particular importance in large-scale destruction of stockpiled chemical weapons.
In the result of numerous recent investigations, the great experimental and clinical experience has been accumulated in studies of perse treatment and prophylactic means and drugs, which can be used in OP poisonings.
The major approaches to prophylactics and treatment of intoxication caused by OP inhibitors are mainly reduced to the application of carbamates (as pretreatment means) and anticholinergic agents, cholinesterase reactivators, and anticonvulsants (as medicines).
As a rule, multicomponent and combined medication, with the simultaneous or consequential use of several drugs or their mixtures, is required for the efficient treatment of OP poisonings. Because of insufficient efficacy of the existing medicinal means and side effects of the present-day drugs, which can cause mental disorders of the human, further searches for new pharmaceuticals to be used in the prophylactics and therapy of OP poisonings are necessary.
One of the latest advances in this field is the use of cholinesterases as prophylactic drugs, which abolish toxic effects of OP inhibitors. As it was convincingly demonstrated in tests on mice and monkeys, the prevention from the effects of OP inhibitors in the blood circulation system due to a preliminary administration of exogenous cholinesterases has a clear advantage over traditionally used antidotes, since these enzymes afford a good protection from several lethal doses of highly toxic OP agents, such as Vx and soman, in the absence of any symptoms of mental disorders in the studied animal species. Furthermore, more recent studies have showed that human blood plasma butyrylcholinesterase (BuChE) can be the most promising prophylactic antidote. Also, human blood BuChE preparations may find application in anesthesiology and narcology.
So, it follows from the aforementioned that practically important and multipurpose pharmaceuticals can be created on the basis of human plasma BuChE.
Within the frames of ISTC Project # 162 executed in GosNIIOKhT in 1995-1999, it was revealed that Central Asian cobra (Naja naja oxiana) venom acetylcholinesterase (AChE) and horse serum BuChE exerted the pronounced prophylactic antidotal activity in poisoning by GD-42, an analogue of thiocholine phosphonates, and reduced its toxicity by three times. Advanced methods to isolate and purify cholinesterases from various natural sources were also developed in GosNIIOKhT. The gained experience of scientists and specialists can successfully be used to develop the methods for the production and biomedical assays of human blood plasma BuChE.
This Project will also include gene engineering and molecular biological studies focused on the construction and expression of the human BuChE-encoding gene in prokaryotes and eukaryotes. Specialists from the Participating Institute, GosNIIGenetika, have long-standing experience in this field.
The aim of this Project is to produce highly active human blood plasma BuChE preparation by gene engineering methods to provide for a reliable protection from several lethal doses of soman, sarin, and Vx in the absence of symptoms of toxic OP effects.
The Project includes the following stages:
1. Isolation and production of highly purified BuChE preparations from the human blood serum.
2. Evaluations of the prophylactic antidotal activity of human blood serum BuChE in poisoning by soman, sarin, and Vx.
3. Development of the gene-engineering method to produce human blood serum BuChE.
4. Development of methods for isolation and purification of the enzyme from raw material produced by microorganisms.
5. Studies on the possibility of using highly active gene-engineered BuChE preparations to create new powerful means and drugs for the prophylactics and treatment of OP poisonings.
Expected results of the Project are (i) the developed method of gene-engineered human blood plasma BuChE production and (ii) isolation of highly purified BuChE preparation to be used potentially as a powerful pretreatment (prophylactic) drug against toxic effects of OP poisoning agents, such as sarin, soman, and Vx.