ABSTRACT
Using the patch-clamp method in the whole-cell configuration, we showed that the new derivatives of 2-aminothiophene-3-carboxylic acid, which were synthesized by us earlier, can both block (compound 1) and potentiate (compound 2) calcium-activated chloride currents in single rat cerebellar Purkinje cells.
Subject(s)
Chloride Channels/metabolism , Membrane Potentials/drug effects , Purkinje Cells/metabolism , Toluidines , Animals , Cells, Cultured , Rats , Toluidines/chemical synthesis , Toluidines/chemistry , Toluidines/pharmacologyABSTRACT
Psychotropic properties of CA-7043× and CA-7050×, new fluorinated derivatives of tetrahydrocarbasoles, were examined on outbred CD1 mice and transgenic 5×FAD mice with Alzheimer disease. Both agents exerted cognitive-stimulating and anxiolytic effects in a dose of 5 mg/kg. In the new cage test, they retarded extinction of orientation and exploratory behavior. CA-7043× produced an anxiolytic effect on CD1 mice assessed in the open-field test and exerted cognitive-stimulating action in the new location test. In the same tests, CA-7050× demonstrated the cognitive-stimulating and anxiolytic effects on transgenic 5×FAD mice.
Subject(s)
Anti-Anxiety Agents/pharmacology , Anxiety/drug therapy , Behavior, Animal/drug effects , Carbazoles/pharmacology , Exploratory Behavior/drug effects , Hydrocarbons, Fluorinated/pharmacology , Maze Learning/drug effects , Psychotropic Drugs/pharmacology , Alzheimer Disease/drug therapy , Animals , Disease Models, Animal , Male , Mice , Mice, TransgenicSubject(s)
Esterases/antagonists & inhibitors , Organophosphorus Compounds/chemistry , Organophosphorus Compounds/pharmacology , Structure-Activity Relationship , Animals , Cholinesterase Inhibitors/adverse effects , Cholinesterase Inhibitors/pharmacology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , Hydrophobic and Hydrophilic Interactions , Lactates/chemistry , Organophosphorus Compounds/adverse effects , PhosphorylationABSTRACT
This paper reviews previously published data and presents new results to address the hypothesis that fluorinated aminophosphonates (FAPs), (RO)(2)P(O)C(CF(3))(2)NHS(O)(2)C(6)H(5), R=alkyl, inhibit serine esterases by scission of the P-C bond. Kinetics studies demonstrated that FAPs are progressive irreversible inhibitors of acetylcholinesterase (AChE, EC 3.1.1.7.), butyrylcholinesterase (BChE, EC 3.1.1.8.), carboxylesterase (CaE, EC 3.1.1.1.), and neuropathy target esterase (NTE, EC 3.1.1.5.), consistent with P-C bond breakage. Chemical reactivity experiments showed that diMe-FAP and diEt-FAP react with water to yield the corresponding dialkylphosphates and (CF(3))(2)CHNHS(O)(2)C(6)H(5), indicating lability of the P-C bond. X-ray crystallography of diEt-FAP revealed an elongated (and therefore weaker) P-C bond (1.8797 (13)A) compared to P-C bonds in dialkylphosphonates lacking alpha-CF(3) groups (1.805-1.822A). Semi-empirical and non-empirical molecular modeling of diEt-FAP and (EtO)(2)P(O)C(CH(3))(2)NHS(O)(2)C(6)H(5) (diEt-AP), which lacks CF(3) groups, indicated lengthening and destabilization of the P-C bond in diEt-FAP compared to diEt-AP. Active site peptide adducts formed by reacting diEt-FAP with BChE and diBu-FAP with NTE catalytic domain (NEST) were identified using peptide mass mapping with mass spectrometry (MS). Mass shifts (mean+/-SE, average mass) for peaks corresponding to active site peptides with diethylphosphoryl and monoethylphosphoryl adducts on BChE were 136.1+/-0.1 and 108.0+/-0.1Da, respectively. Corresponding mass shifts for dibutylphosphoryl and monobutylphosphoryl adducts on NEST were 191.8+/-0.2 and 135.5+/-0.1Da, respectively. Each of these values was statistically identical to the theoretical mass shift for each dialkylphosphoryl and monoalkylphosphoryl species. The MS results demonstrate that inhibition of BChE and NEST by FAPs yields dialkylphosphoryl and monoalkylphosphoryl adducts, consistent with phosphorylation via P-C bond cleavage and aging by net dealkylation. Taken together, predictions from enzyme kinetics, chemical reactivity, X-ray crystallography, and molecular modeling were confirmed by MS and support the hypothesis that FAPs inhibit serine esterases via scission of the P-C bond.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Esterases/antagonists & inhibitors , Halogenation , Organophosphonates/chemistry , Organophosphonates/pharmacology , Animals , Crystallography, X-Ray , Esterases/chemistry , Esterases/metabolism , Humans , Kinetics , Mass Spectrometry , Models, Molecular , Molecular Conformation , Peptide MappingSubject(s)
Neurotoxins/chemistry , Oximes/chemistry , Acetylcholinesterase/metabolism , Animals , Carboxylic Ester Hydrolases/antagonists & inhibitors , Carboxylic Ester Hydrolases/chemistry , Chickens , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/toxicity , Humans , Least-Squares Analysis , Models, Chemical , Neurotoxins/toxicity , Oximes/toxicitySubject(s)
Cholinesterases/metabolism , Esterases/antagonists & inhibitors , Esterases/chemistry , Organophosphorus Compounds/metabolism , Butyrylcholinesterase/metabolism , Carboxylic Ester Hydrolases/antagonists & inhibitors , Carboxylic Ester Hydrolases/metabolism , Cholinesterase Inhibitors/pharmacology , Cholinesterases/chemistry , Esterases/metabolism , Kinetics , Phosphorylation , Phosphotransferases/metabolismSubject(s)
Enzyme Inhibitors/pharmacology , Fluorine/pharmacology , Organophosphonates/pharmacology , Serine Endopeptidases/metabolism , Biochemistry/methods , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Fluorine/chemistry , Humans , Magnetic Resonance Spectroscopy , Models, Chemical , Models, Theoretical , Serine Endopeptidases/chemistry , Time FactorsABSTRACT
5,5-Bis(hydroxymethyl)-2-oxo-[1-(2-trifluoromethyl)-3,3,3- trifluoropropionamido)-1-trifluoromethyl-2,2,2-trifluoroethyl- 1,3,2-dioxaphosphan (CA-423) is an in vitro inhibitor of the Escherichia coli uridine and thymidine phosphorylases. Unlike widely studied nucleoside analogues, this compound binds to the enzymes irreversibly. Its LD50 in mice was 40 mg/kg. Due to the involvement of pyrimidine phosphorylases in carcinogenesis and the relatively low toxicity of CA-423, it is promising for anticancer therapy.
Subject(s)
Enzyme Inhibitors/pharmacology , Organophosphorus Compounds/pharmacology , Propionates/pharmacology , Thymidine Phosphorylase/antagonists & inhibitors , Animals , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/toxicity , Escherichia coli/enzymology , Lethal Dose 50 , Magnetic Resonance Spectroscopy , Mice , Organophosphorus Compounds/chemistry , Organophosphorus Compounds/toxicity , Propionates/chemistry , Propionates/toxicitySubject(s)
Calcium/pharmacology , Cholinesterase Inhibitors/toxicity , Hydrocarbons, Chlorinated/antagonists & inhibitors , Acetylcholinesterase/metabolism , Animals , Butyrylcholinesterase/metabolism , Guinea Pigs , Horses , Humans , Hydrocarbons, Chlorinated/toxicity , In Vitro Techniques , Male , MiceABSTRACT
The effect of the organophosphoric inhibitor, SA-152, on the fibrinogen-coagulating and TAME-esterase activity of bovine alpha-thrombin was studied. The irreversible inhibition constants (k11 = 1.1 x 10(4) M-1.min-1,Ki = 0.7 x 10(-4) M, k2 = 0.8 min-1 towards the coagulating activity and kII = 0.7 x 10(4) M-1.min-1, Ki = 0.3 x 10(-4) M, k2 = 0.2 min-1 towards the esterase activity) were determined. The SA-152 inactivated alpha-thrombin was dialyzed and incubated with 0.5 M and 2.5 M NaCl and 10 mM TAME. There was no reconstitution of activity of the SA-152 modified alpha-thrombin after dialysis and treatment with high concentrations of NaCl and TAME. Heparin interactions with the anion-binding site of the high molecular weight recognition center in the alpha-thrombin molecule did not significantly influence the values of the kinetic constants for the enzyme inhibition by SA-152. This finding is consistent with the hypothesis on the irreversible binding of SA-152 in the active center of the enzyme.
Subject(s)
Organophosphorus Compounds/pharmacology , Thrombin/antagonists & inhibitors , Animals , Binding Sites , Cattle , Fibrinogen/antagonists & inhibitors , Kinetics , Molecular Weight , Peptide Hydrolases/metabolism , Thrombin/metabolismABSTRACT
Influence of 4-E-BPE on the amplitude of population spices (PS) evoked in CA1 area by Shaffer collateral stimulation in hippocampal slices were analysed. Bath application of 4-E-BPE (10(-6)-10(-5) M) led to a pronounced increase in the amplitude of the PS, the appearance of secondary PS and then introduction of GABA led to restoring original state. The 4-E-BPE was more potent than picrotoxin. These findings suggest that 4-E-BPE suppress inhibitory synaptic transmission in the CA1 region of hippocampus.
Subject(s)
Bridged Bicyclo Compounds, Heterocyclic , Bridged Bicyclo Compounds/pharmacology , GABA Antagonists , Hippocampus/physiology , Neurons/physiology , Organophosphorus Compounds/pharmacology , Synapses/physiology , Animals , Evoked Potentials , Hippocampus/drug effects , In Vitro Techniques , Mice , Mice, Inbred BALB C , Neurons/drug effects , Picrotoxin/pharmacology , Synapses/drug effectsABSTRACT
A series of O,O-diethyl-1-(N-alpha-hydrohexafluoroisobutyryl)aminoalkylphos phonates (APh) has been synthesized and their interaction with human erythrocyte acetylcholinesterase (AChE) and with horse serum butyrylcholinesterase (BuChE) studied. Most of the APhs inactivated the cholinesterases irreversible through formation of the enzyme-inhibitor intermediate. The inactivation rate constants and the enzyme-inhibitor intermediate dissociation constants are calculated. The quantitative structure-activity relationships including both hydrophobic and calculated steric parameters of substituents are developed for APh--ChE interactions. Molecular mechanics (programme MM2) was used for determining steric parameters (Es). On the basis of QSAR models analysis it was concluded that hydrophobic interactions play an essential role in APh--AChE binding, whereas for APh--BuChE binding steric interactions are essential. Presence of at least two APh binding centres on the surface of AChE and BuChE is suggested.
Subject(s)
Cholinesterase Inhibitors/chemistry , Fluorine/chemistry , Organophosphorus Compounds/chemistry , Acetylcholinesterase/blood , Animals , Binding Sites , Butyrylcholinesterase/blood , Erythrocytes/enzymology , Horses , Humans , MathematicsSubject(s)
Cholinesterase Inhibitors/chemical synthesis , Oximes/chemical synthesis , Acetylcholinesterase/metabolism , Animals , Butyrylcholinesterase/metabolism , Chemical Phenomena , Chemistry , Cholinesterase Inhibitors/toxicity , Hydrolysis , Lethal Dose 50 , Mice , Oximes/pharmacology , Oximes/toxicityABSTRACT
Influence of O,O,-diethyl-1-(N-alpha-hydrohexafluoroisobutyryl)amino-1- methylpropylphosphonate and O,O-diisobutyl-1-[2-(ethoxycarbonyl)aminoperfluoroprop-2-yl] -1- methylpropylphosphonate on the level of production of human proinsulin secreted by a genetically engineered culture Bacillus subtilis AJ 73 (pBINS1.0.) has been studied. The above phosphonates, being non-toxic for microorganisms, reduced degradation of proinsulin by serine proteinases.
Subject(s)
Bacillus subtilis/metabolism , Proinsulin/biosynthesis , Protease Inhibitors/pharmacology , Animals , Genetic Engineering , Humans , Insulin Antagonists , Recombinant Proteins/biosynthesis , SwineSubject(s)
Lupus Erythematosus, Systemic/complications , Thromboembolism/etiology , Adolescent , Adult , Autoantibodies/analysis , Blood Coagulation Factors/analysis , Blood Coagulation Factors/immunology , Cardiolipins/immunology , Chronic Disease , Female , Humans , Lupus Coagulation Inhibitor , Lupus Erythematosus, Systemic/immunology , Male , Middle Aged , Phospholipids/immunology , Thromboembolism/immunologyABSTRACT
Using a blind method for assessing the results, a study was made of the effect of dimethylsulfoxide (DMSO) on fibrin formation and microcirculation in 42 patients with rheumatic diseases (rheumatoid arthritis, systemic scleroderma, Raynaud's syndrome). It has been shown that the therapeutic effect of DMSO in rheumatic diseases is determined to a definite degree by its normalizing action on fibrin formation and microcirculation.
Subject(s)
Dimethyl Sulfoxide/therapeutic use , Hand/blood supply , Rheumatic Diseases/drug therapy , Thrombelastography , Drug Therapy, Combination , Gels , Humans , Microcirculation/drug effects , Microcirculation/physiopathology , Niacin/therapeutic use , Randomized Controlled Trials as Topic , Rheumatic Diseases/blood , Rheumatic Diseases/physiopathology , Time FactorsABSTRACT
Studies have been made on the interaction of four types of phosphorylated alkylchloroformoximes, i.e. analogues of an insecticide-acaricide valexon, with acetylcholinesterases from human erythrocytes and from the heads of the housefly Musca domestica. Antiacetylcholinesterase activity of the drugs depended both on the structure of the organophosphorus compounds, and the origin of the enzyme, indicating the existence of differences in the active surface of these acetylcholinesterases. Incorporation of one or two chloride atoms into alkylchloroformoxime group of the cleaved part of the organophosphorus compounds increased anticholinesterase activity with respect to both enzymes. Diethyl derivatives of these drugs exhibited higher specificity with respect to housefly enzyme as compared to human acetylcholinesterase.
