Track topics on Twitter Track topics that are important to you
Organophosphorus compound (OP) tabun is resistant to reactivate by many oxime drugs after the formation of OP-conjugate with AChE. The reactivation of tabun-inhibited mAChE and site-directed mutants by bispyridinium oxime, K048 (N-[4-(4-hydroxyiminomethylpyridinio)butyl]-4-carbamoylpyridinium dibromide) showed that the mutations significantly poor the overall reactivation efficacy of K048. We have unravelled the lowered efficacy of K048 with the tabun-mutant mAChE(Y337A) using docking and steered molecular dynamics (SMD) simulations. The computed results showed some interesting features for the interaction of drug molecule K048 with tabun-mAChE(wild-type) and tabun-mutant mAChE(Y337A). The SMD simulations showed that the active pyridinium ring of K048 is directed towards the phosphorus atom conjugated to the active serine (SUN203) of tabun-mAChE(wild-type). The cradle shaped residues Tyr337-Phe338 present in the choline binding site stabilize the active pyridinium ring of K048 with π-π interaction and the residue Trp86 involved in T-shaped cation-π interaction. However, in the case of tabun-mutant mAChE(Y337A).K048 conjugate, the replacement of aromatic Tyr337 with the aliphatic alanine unit in the choline binding site, however, loses one of the π-π interaction between the active pyridinium ring of K048 and the Tyr337. The placement of aliphatic alanine unit resulted in the displacement of the side chain of Phe338 towards the His447. Such displacement is causing the inaccessibility of the drug towards the phosphorus atom conjugated to the active serine (SUN203) of tabun-mutant mAChE(Y337A). Furthermore, the unbinding of the K048 with SMD studies showed that the active pyridinium ring of the drug undergoes a complete turn along the gorge axis and is directed away from the phosphorus atom conjugated to the active serine of the tabun-mutant mAChE(Y337A). Such effects inside the gorge of tabun-mutant mAChE(Y337A) would lower the efficacy of the drug molecule (K048) for the reactivation process. The binding free energy computed for the tabun-mAChE(wild-type) and tabun-mutant mAChE(Y337A) with K048 showed that the drug molecule prefers to bind strongly with the former enzyme (∼30 kJ/mol) than the later one.
This article was published in the following journal.
Name: Chemico-biological interactions
Tabun represents the phosphoramidate class of organophosphates that are covalent inhibitors of acetylcholinesterase (AChE), an essential enzyme in neurotransmission. Currently used therapy in countera...
Acetylcholinesterase (AChE), an enzyme that degrades the neurotransmitter acetylcholine, when covalently inhibited by organophosphorus compounds (OPs), such as nerve agents and pesticides, can be reac...
Chloroquine (CQ) has been used for decades as the primary chemotherapeutic drug for the treatment of malaria. The emergence of drug resistance in Plasmodium falciparum has been considered to be becaus...
A new series of nonquaternary conjugates for reactivation of both nerve agents and pesticides inhibited hAChE were described in this paper. It was found that substituted salicylaldehydes conjugated to...
TERT promoter mutations reactivate telomerase, allowing for indefinite telomere maintenance and enabling cellular immortalization. These mutations specifically recruit the multimeric ETS factor GABP, ...
The primary objective of this study is to assess the performance of an in silico designed alternative protocol for control of stress hyperglycemia of inpatients treated for Coronary Artery...
PRECISE is a study to discover new detection, prognosis and treatment biomarkers for cancer. This is a prospective, multi-center, observational study designed to collect de-identified bios...
A phase-I-first in man study in patients with calreticulin(CALR)-mutant MPN by vaccinating with exon 9 mutated peptide with the adjuvant Montanide ISA-51 to monitor safety and toxicity and...
The study is being conducted to evaluate the efficacy, safety and tolerability of famitinib combined with HS-10296 in subjects with advanced EGFR-mutant NSCLC.
Clinical efficacy of FLT3 inhibitors combining with chemotherapy is usually transient and followed by emergence of drug-resistance in FLT3-ITD mutant AML. BTK is reported to be a therapeut...
Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
Studies designed to examine associations, commonly, hypothesized causal relations. They are usually concerned with identifying or measuring the effects of risk factors or exposures. The common types of analytic study are CASE-CONTROL STUDIES; COHORT STUDIES; and CROSS-SECTIONAL STUDIES.
Works about research studies that evaluate interventions or exposures on biomedical or health-related outcomes. The two main types of clinical studies are interventional studies (clinical trials) and observational studies.
Mice bearing mutant genes which are phenotypically expressed in the animals.
Pharmacy is the science and technique of preparing as well as dispensing drugs and medicines. It is a health profession that links health sciences with chemical sciences and aims to ensure the safe and effective use of pharmaceutical drugs. The scope of...
Clinical Approvals Clinical Trials Drug Approvals Drug Delivery Drug Discovery Generics Drugs Prescription Drugs In the fields of medicine, biotechnology and pharmacology, drug discovery is the process by which drugs are dis...
Enzymes are proteins that catalyze (i.e., increase the rates of) chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical re...