The mechanism of reaction between esterases and phosphorus-containing anti-esterases

Jandrof, B. J.; Michel, Harry O.; Schaffer, Norwood K.; Egan, Richard S.; Summerson, William H.

doi:10.1039/df9552000134

Cited by 93 publications

(17 citation statements)

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“…Under these conditions the results (Fig. 3) were very similar to those of Axelsson et al (2). The two mutations are probably indistinguishable, or even identical.…”

Section: A-benzoyl-dl-arginine-pnitroanilide (Bapna) By Trypsin (3) supporting

confidence: 89%

Dealkylation and Loss of Capacity for Reactivation of Cholinesterase Inhibited by Sarin

Harris

Fleisher

Clark

et al. 1966

Science

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Inhibition of rat brain acetylcholinesterase by (32)P-sarin in vivo results initially in (32)P-isopropylmethylphosphonylated enzyme. The percentage of inhibited enzyme that could not be reactivated by pyridinium aldoxime methochloride (aged enzyme) approximated the amount of radioactivity identified as (32)P-methylphosphonate. The (32)P-isopropyl methylphosphonate not released fromthe inhibited enzyme by the oxime accounted for 51 +/- 10 percent ( standard deviation) of the radioactivity fixed to brain tissue. It showed no correlation with aging and was probably bound to sites other than acetylcholinesterase.

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“…Under these conditions the results (Fig. 3) were very similar to those of Axelsson et al (2). The two mutations are probably indistinguishable, or even identical.…”

Section: A-benzoyl-dl-arginine-pnitroanilide (Bapna) By Trypsin (3) supporting

confidence: 89%

Dealkylation and Loss of Capacity for Reactivation of Cholinesterase Inhibited by Sarin

Harris

Fleisher

Clark

et al. 1966

Science

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“…The sensitivity of blood cholinesterases to sarin and VX has been described -for human erythrocyte AChE -as about 10 times higher for VX in comparison with sarin (Worek et al 2004). Jandorf et al (1955) determined the bimolecular rate constant for rat erythrocyte AChE to be approximately 10 7 , and this is in agreement with our data. The inhibition constant occurring in the literature more frequently -IC 50can be derived from the equation (I), but this constant is very dependent on the time of incubation of the enzyme with an inhibitor.…”

Section: Discussionsupporting

confidence: 90%

“…Although there are many studies on the inhibition and reactivation of cholinesterases in vitro (Kuča et al 2004, Patočka et al 2005, Musílek et al 2007, Petroianu and Kalasz 2007, Hasan et al 2008, there is a lack of complex data on the most usual and available animal -the ratfor all tissues of interest. There are separate data on the affinity in vitro of different OP to: human (Jandorf et al 1955, Tammelin 1957, Aquilonius et al 1964, Patočka and Tulach 1969, Aurbek et al 2006); pig (Bajgar et al 1971, Aurbek et al 2006); erythrocyte AChE, and plasma BuChE (Tammelin 1957, Aquilonius et al 1964, Back 1969, Bajgar et al 1971, or brain AChE (Back 1969, Patočka and Bajgar 1971, Bajgar and Patočka 1977 etc. Inhibition constants inform us about the kinetics of the enzymes mentioned but do not correspond to the real status, i.e.…”

Section: Introductionmentioning

confidence: 99%

Inhibition of blood cholinesterases by nerve agents in vitro

Bajgar¹,

Jun²,

Kuča³

et al. 2009

J Appl Biomed

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The bimolecular rate constants (k a ) of inhibition were determined for cholinesterase in rat blood in vivo and three nerve agents in vitro. They were in the range of 10 5 -10 6 M·min -1 with the highest value for VX (k a = 8.92 × 10 6 ), the next highest for soman (k a = 3.22 × 10 6 ) and the lowest for sarin (k a = 0.39 × 10 6 ), respectively. The inhibition rate is the same in vitro and in vivo; when the real inhibition in vivo and in vitro is compared, it is possible to assess the concentration of the nerve agent present in the blood stream. When administered intramuscularly it is about 70% of the dose administered.

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“…The nature of this enzyme has been probed by various inhibition studies [Friess (274) ; Bergmann (275)]. The use of certain phos phate esters as insecticides and chemical warfare agents is based upon their inhibition of this enzyme; several studies on such inhibition and its reversal have appeared (276,277,278) . Studies on ester hydrolysis catalyzed by horse liver esterase have been interpreted in rather different mechanisms by Kistiakowsky (279) and Christiansen (280) .…”

Section: Enzyme-catalyzed Reactionsmentioning

confidence: 99%

Kinetics of Reactions in Solution

King¹

1957

Annu. Rev. Phys. Chem.

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This review deals with homogeneous reactions in liquid solution; studies in the areas of photochemistry, radiation chemistry, and polymerization kinetics are not reviewed. A short review of the past year's work in enzyme kinetics is included, and this inclusion has necessitated a somewhat ab breviated review of organic reactions. In a sense, the entire review is ab breviated since fewer than half of the worth-while papers published during the year are included.A short book by Dainton (1) on chain reactions, including those in solu tions, has appeared during the year as have reviews of the kinetic studies published in 1955 [Noyes (2); Ashmore et al. (3)]. Guggenheim (4) sets the record straight on the early history of kinetics and points out that the lack of correlation between the reaction order and the coefficients in the chemical equation was realized by the earliest workers in the field. If the teacher wishes to emphasize this point, a nice example is the reaction, 30 ROH + BloH14�10 B(OR)a+22 H2, which Beachell (5) finds to be first order in ROH and in B1oH14•The design of a four-channel stop flow mixing apparatus for use with the Beckman D.U. spectrophotometer is presented by Beers (6), and De Tar (7) describes apparatus for the precise manometric determination of rate data. Under the heading of neat tricks is Winstein's use of a tape recorder for not ing the time of quenching of reaction mixture aliquots (8); this technique should prove useful for the solitary researcher who is studying a relatively rapid reaction.Westman & De Lury (9) have considered the integrated rate equations for consecutive first order reactions, and Widequist (10) describes a method for the calculation of the rate constants for two competitive, consecutive reactions; this method is applicable to experiments in which the reactants are present in nonequivalent amounts.Harris & Weale (11) have measured the rates of several reactions as a function of pressure up to pressures of 5000 atm. The value of l:!. vt is often dramatically different at high pressures from what it is at one atmosphere, a point also stressed by Hamann (12).Noyes (13) has presented theoretical considerations pertaining to diffu sion controlled reactions and concludes that current data suggest "that dif fusion in liquids involves almost continuous motion and small individual displacements, and does not involve 'jumps' of the order of a molecular di ameter that are opposed by significant potential barriers." Other theoretical papers dealing with diffusion controlled reactions are by Schulz (14) and 1 The survey of literature pertaining to this review was completed in December, 1956. 273 Annu. Rev. Phys. Chem. 1957.8:273-298. Downloaded from www.annualreviews.org Access provided by McMaster University on 02/06/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS

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The mechanism of reaction between esterases and phosphorus-containing anti-esterases

Cited by 93 publications

References 1 publication

Dealkylation and Loss of Capacity for Reactivation of Cholinesterase Inhibited by Sarin

Dealkylation and Loss of Capacity for Reactivation of Cholinesterase Inhibited by Sarin

Inhibition of blood cholinesterases by nerve agents in vitro

Kinetics of Reactions in Solution

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