Mercury benzoate

Prostatic acid phosphatase is reversibly inactivated by p-mercuri-benzoate and by Cu2+ and Fe3+ (59). In contrast to red cell acid phosphatase, prostatic acid phosphatase is only partially inactivated even after prolonged periods of incubation at high concentrations of p-mercuri-benzoate. Addition of cysteine to the p-mercuribenzoate-treated enzyme produces complete reactivation. Binding of SH groups by p-mercuri-benzoate renders the enzyme more labile to thermal denaturation, but no difference is obtained with surface inactivation (23). Similar partial inactivation with Cu2+ is also subject to reactivation. 

Chemical modification of soybean agglutinin by acetylation of its amino groups resulted in little loss of agglutinating activity, whereas the protein was quite sensitive to modification of its tyrosyl residues.547 Failure of the protein to react with 2-iodoacetamide or p-(chloro-mercuri)benzoate in 6 M urea confirmed that it was devoid of sulfhydryl groups. A metalloprotein containing151 Ca2+ and Mn2+, the soybean lectin is inactivated by Al3+, Fe3+, and Pb2+, whereas Mn2+, Ba2+, Mg2+, Ag+, Li+, and K+ are without effect.532... 

A very important conclusion was reached based on the effect of p-mer-curibenzoate on the NADPH oxidase and the NADPH-cjrtochrome c reductase activities of microsomes, namely, that the natural acceptor might be a component reactive with oxygen and involved in hydroxyla-tions or demethylations (11). It was found that in the absence of cytochrome c, the oxidase activity was largely inhibited by p-mercuri-benzoate. In the presence of cytochrome c, NADPH oxidation exceeded cytochrome c reduction in the absence of p-mercuribenzoate and the two rates equaled each other in the presence of p-mercuribenzoate. Thus, a mercurial sensitive oxidase distinct from the reductase was indicated, and this component was hypothesized to be connected with hydroxylation and/or demethyktion (11). 

The effects of temperature on the distribution of non-electrolytes between erythrocytes and the surrounding medium in vitro has been investigated with H NMR. The results indicated that between 4° and 37° the rate of uptake by erythrocytes was a function of temperature. The inhibition of water-permeability by diffusion (P ) through the erythrocyte membrane has been investigated using NMR. Maximal inhibition of 50% of Pd was achieved by 2 mM -chloromercuri benzoate in 20 min. The maximal effect of />-chloro-mercuri benzoate was reduced by the presence of lipophilic solutes. However, lipophilic solutes alone caused a faster inhibition of Pd, though this was less efficient than that from p-chloromercuri benzoate. A method has been developed to observe early phosphate penetration into erythrocytes. When the main extracellular cation was Na, 100 mM extracellular Pi penetrated the cells within one hour. When the main extracellular cation was the apparent penetration rate of Pi was reduced by 25%. The influx of Pi into erythrocytes was not accompanied by a change in pHj. ... 

Regulation of liver D-fructose 1,6-diphosphatase could involve modification of the sulfhydryl group of the enzyme.397 Cystamine (2,2 -dithiobisethylamine) or homocysteine undergoes a disulfide exchange-reaction with two reactive cysteine residues. This exchange leads to a four-fold increase in catalytic activity.405 Other sulfhydryl reagents, such as l-fluoro-2,4-dinitrobenzene (FDNB), p-mercuri-benzoate (PMB), and 2-iodoacetamide, also activate liver D-fructose... 

Methyl Mercury Benzoate CAS 3626-13-9 Agent Index A151... 

Classification Specially denatured alcohol Definition Ethyl alcohol (100 gal) denatured with (1) potassium iodide USP (80 g) and red mercuric iodide NF (109 g), or (2) thimerosal USP (95 g) or (3) 76 g of any of phenyl mercuric nitrate NF, phenyl mercury chloride NF, or phenyl mercury benzoate... 

Thiols at a concentration of 10 to 40 mM also act as antagonists to the action of neuropeptides on rat uterus, but not to their pressor effect Such a difference could be due to a difference in the receptors. Thioglycollate (10 mM) and cysteine (10 mM) inhibit the permeability response of the toad bladder to oxytocin or vasopressin. Gluthathione has a similar effect These actions of the peptides are also inhibited after incubation of the tissues in the presence of either N-ethyl- or N-phenylaleimide which form covalent bonds with sulphydryl groups or complex mercury mercaptides (p-hydroxy-mercury-benzoate, p-chloro-mercury-benzoate). These results show that the receptor presents in its constitution some functional sulphydryl groups. 

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