scholarly journals SOME FACTORS WHICH INFLUENCE THE OXIDATION OF SULFHYDRYL GROUPS

1942 ◽  
Vol 25 (3) ◽  
pp. 355-367 ◽  
Author(s):  
M. L. Anson
Keyword(s):  
Uric Acid ◽  
Acid Solution ◽  
Copper Sulfate ◽  
Guanidine Hydrochloride ◽  
Sulfate Solution ◽  
Alkyl Sulfate ◽  
Neutral Solution ◽  
Egg Albumin ◽  
Sh Groups ◽  
Acid Reagent

1. Cyanide inhibits the oxidation of the SH groups of cysteine and denatured egg albumin by the uric acid reagent. 2. At pH 4.8 cysteine is oxidized by the uric acid reagent and by ferricyanide in the presence but not in the absence of added copper sulfate. 3. In neutral solution, the uric acid reagent oxidizes the SH groups of denatured egg albumin in the presence of urea but not in the presence of alkyl sulfate or in the absence of denaturing agents. 4. Ferricyanide oxidizes the SH groups of neutral denatured egg albumin even in the presence of alkyl sulfate or, if precautions are taken to avoid aggregation, in the absence of denaturing agents. 5. In acid solution, ferricyanide does not oxidize the SH groups of denatured egg albumin completely. The oxidation is more complete, however, in the presence of urea than in the presence of alkyl sulfate, and more complete in the presence of guanidine hydrochloride than in the presence of urea. 6. The uric acid reagent which does not oxidize the SH groups of neutral denatured but unhydrolyzed egg albumin in the absence of denaturing agents does, under the same conditions, oxidize the SH groups of egg albumin partially hydrolyzed by pepsin. 7. At pH 4.8 in alkyl sulfate solution ferricyanide oxidizes the SH groups of digested egg albumin more completely than the SH groups of denatured but undigested egg albumin.

scholarly journals THE SULFHYDRYL GROUPS OF EGG ALBUMIN

1941 ◽  
Vol 24 (4) ◽  
pp. 399-421 ◽  
Author(s):  
M. L. Anson
Keyword(s):  
Guanidine Hydrochloride ◽  
Sulfhydryl Groups ◽  
Urea Solution ◽  
Ferricyanide Reduction ◽  
Native Form ◽  
Egg Albumin ◽  
Sh Groups ◽  
Reduction Test ◽  
Hydrochloride Solution

1. 1 cc. of 0.001 M ferricyanide, tetrathionate, or p-chloromercuribenzoate is required to abolish the SH groups of 10 mg. of denatured egg albumin in guanidine hydrochloride or Duponol PC solution. Both the nitroprusside test and the ferricyanide reduction test are used to show that the SH groups have been abolished. 2. 1 cc. of 0.001 M ferrocyanide is formed when ferricyanide is added to 10 mg. of denatured egg albumin in neutral guanidine hydrochloride or urea solution. The amount of ferricyanide reduced to ferrocyanide by the SH groups of the denatured egg albumin is, within wide limits, independent of the ferricyanide concentration. 3. Ferricyanide and p-chloromercuribenzoate react more rapidly than tetrathionate with the SH groups of denatured egg albumin in both guanidine hydrochloride solution and in Duponol PC solution. 4. Cyanide inhibits the oxidation of the SH groups of denatured egg albumin by ferricyanide. 5. Some samples of guanidine hydrochloride contain impurities which bring about the abolition of SH groups of denatured egg albumin and so interfere with the SH titration and the nitroprusside test. This interference can be diminished by using especially purified guanidine hydrochloride, adding the titrating agent before the protein has been allowed to stand in guanidine hydrochloride solution, and carrying out the nitroprusside test in the presence of a small amount of cyanide. 6. The SH groups of egg albumin can be abolished by reaction of the native form of the protein with iodine. It is possible to oxidize all the SH groups with iodine without oxidizing many of the SH groups beyond the S-S stage and without converting many tyrosine groups into di-iodotyrosine groups. 7. p-chloromercuribenzoate combines with native egg albumin either not at all or much more loosely than it combines with the SH groups of denatured egg albumin or of cysteine. 8. The compound of mercuribenzoate and SH, like the compound of aldehyde and SH and like the SH in native egg albumin, does not give a nitroprusside test or reduce ferricyanide but does reduce iodine.

scholarly journals SULFHYDRYL GROUPS OF EGG ALBUMIN IN DIFFERENT DENATURING AGENTS

1941 ◽  
Vol 24 (6) ◽  
pp. 709-723 ◽  
Author(s):  
A. E. Mirsky
Keyword(s):  
Isoelectric Point ◽  
Guanidine Hydrochloride ◽  
Sulfhydryl Groups ◽  
Color Reaction ◽  
Neutral Medium ◽  
Egg Albumin ◽  
Sh Groups ◽  
Cysteine Content

1. The reaction between ferricyanide and egg albumin in solutions of urea, guanidine hydrochloride, and Duponol has been investigated. 2. In neutral medium ferricyanide oxidizes all the SH groups of egg albumin that give a color reaction with nitroprusside. In neutral medium ferricyanide appears to react only with the SH groups of egg albumin. The quantity of ferrocyanide formed can accordingly be considered the equivalent of the number of SH groups in egg albumin detectable with nitroprusside. 3. In solutions of urea, guanidine hydrochloride, and Duponol sufficiently concentrated so that all the egg albumin present is denatured, the same number of SH groups are found—equivalent to a cysteine content of 0.96 per cent. 4. In denaturation of egg albumin loss of solubility (solubility not in presence of the denaturing agent, but solubility examined in water at the isoelectric point) and appearance of reactive SH groups are integral parts of the same process. As denaturation proceeds in urea, SH groups are liberated only in the egg albumin with altered solubility and in this albumin the maximum number of SH groups is liberated. In a molecule of egg albumin either all of its SH groups that give a test with nitroprusside are liberated or none of them are.

scholarly journals SOME EFFECTS OF IODINE AND OTHER REAGENTS ON THE STRUCTURE AND ACTIVITY OF TOBACCO MOSAIC VIRUS

1941 ◽  
Vol 24 (6) ◽  
pp. 679-690 ◽  
Author(s):  
M. L. Anson ◽  
W. M. Stanley
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Guanidine Hydrochloride ◽  
Urea Solution ◽  
Nicotiana Glutinosa ◽  
Native Form ◽  
Tobacco Plants ◽  
Sh Groups ◽  
Normal Number ◽  
Acid Reagent

1. Denatured tobacco mosaic virus has a number of SH groups corresponding to its total sulfur content of 0.2 per cent. The SH groups were estimated by titration with ferricyanide, tetrathionate, and p-chloromercuribenzoate in guanidine hydrochloride solution and by reduction of the uric acid reagent in urea solution. 2. The SH groups of tobacco mosaic virus or their precursors can be abolished by reaction of the native form of the virus with iodine. 3. Tobacco mosaic virus whose SH groups have been oxidized beyond the S-S stage by iodine but whose tyrosine groups have not been converted into di-iodotyrosine groups still retains its normal biological activity as shown by the number of lesions it causes on Nicotiana glutinosa plants and by the characteristic disease produced in Turkish tobacco plants. 4. The inoculation of Turkish tobacco plants with active virus whose SH groups have been abolished by iodine results in the production of virus with the normal number of SH groups. 5. If enough iodine is added to tobacco mosaic virus or if the iodine reaction is carried out at a sufficiently high temperature, then the tyrosine groups are converted into di-iodotyrosine groups and the virus is inactivated. 6. Tobacco mosaic virus can be almost completely inactivated by iodoacetamide under conditions under which iodoacetamide reacts with few if any of the protein's SH groups. 7. Tobacco mosaic virus is not inactivated by dilute p-chloromercuribenzoate.

scholarly journals SULFHYDRYL GROUPS IN FILMS OF EGG ALBUMIN

1941 ◽  
Vol 24 (6) ◽  
pp. 725-733 ◽  
Author(s):  
A. E. Mirsky
Keyword(s):  
Film Formation ◽  
Surface Film ◽  
Guanidine Hydrochloride ◽  
Sulfhydryl Groups ◽  
Surface Films ◽  
Fundamental Change ◽  
Egg Albumin ◽  
Sh Groups ◽  
Denatured Proteins ◽  
Albumin Molecule

1. The same number of SH groups reduces ferricyanide in surface films of egg albumin as in albumin denatured by urea, guanidine hydrochloride, Duponol, or heat, provided the ferricyanide reacts with films while they still are at the surface and with the denatured proteins while the denaturing agent (urea, heat, etc.) is present. 2. The SH groups of a suspension of egg albumin made by clumping together many surface films react with ferricyanide in the same sluggish and incomplete manner as do the groups in egg albumin denatured by concentrated urea when the urea is diluted or in albumin denatured by heat when the solution is allowed to cool off. 3. The known change in configuration of the egg albumin molecule when it forms part of a surface film explains why SH groups in the film react with ferricyanide whereas those in native egg albumin do not. In the native egg albumin molecule groups in the interior are inaccessible to certain reagents. A film is so thin that there are no inaccessible groups. 4. Because of the marked resemblance in the properties of egg albumin in surface films and of egg albumin after denaturation by the recognized denaturing agents, it may be supposed that the same fundamental change takes place in denaturation as in film formation—indeed, that film formation is one of the numerous examples of denaturation. This would mean that in general the SH groups of denatured egg albumin reduce ferricyanide and react with certain other reagents because they are no longer inaccessible to these reagents.

Computed tomography assessment of soil and sediment porosity modifications from exposure to an acid copper sulfate solution

2021 ◽  
Vol 108 ◽  
pp. 103194
Author(s):  
Francisco R.A. Ziegler-Rivera ◽  
Blanca Prado ◽  
Alfonso Gastelum-strozzi ◽  
Jorge Márquez ◽  
Lucy Mora ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Copper Sulfate ◽  
Sulfate Solution ◽  
Copper Sulfate Solution ◽  
Soil And Sediment

Surface modification of Mg2Ni alloy in an acid solution of copper sulfate and sulfuric acid

1999 ◽  
Vol 285 (1-2) ◽  
pp. 267-271 ◽  
Author(s):  
C.Y Wang ◽  
P Yao ◽  
D.H Bradhurst ◽  
H.K Liu ◽  
S.X Dou
Keyword(s):  
Surface Modification ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Copper Sulfate

scholarly journals Boron Removal from Aqueous Solutions by Strong Base Anion-exchange Resin Batch and Column Experiments

2021 ◽  
Author(s):  
György Pátzay ◽  
József Dobor ◽  
Emil Csonka ◽  
Gábor Lozsi ◽  
Ferenc Feil
Keyword(s):  
Ion Exchange ◽  
Acid Solution ◽  
Boric Acid ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Free Water ◽  
Sulfate Solution ◽  
Boric Acid Solution ◽  
Strong Base

Borate ion exchange capacity of Purolite NRW600 strong base anion resin in hydroxide form and mixed bed NRW600+NRW100 ion exchange was investigated with static experiments. Anion exchange resin was saturated with 0.1–45 g/dm3 concentration boric acid solution in a static mixer at 20, 30, 40 and 50 °C at 150 rpm for 24 hours. Remaining borate content of saturation solutions was deter-mined with ion chromatography and ICP-OES. The amount of fixed borate as borate anions increased with the saturation borate concentration as well as in case of simple anion exchange as in case of mixed bed.Column sorption-elution study was carried out by using strong base anion exchange resins (Purolite NRW600 and Amberlite IRN78). Resins in hydroxide and in chloride forms were saturated in column with 5–40 g/dm3 boric acid solution in excess. The resin was then eluted with 200 cm3 salt free water with 5 cm3/min at 25 °C and then eluted by 1 mol/dm3 sodium-sulfate solution with 5 cm3/min. The effluent was collected and analyzed for borate content by titrimetric method. In chloride form the resin adsorbed and released much less borate. Effective borate and polyborate sorption needs hydroxide ions in resin phase.

scholarly journals Efficacy of Copper Sulfate-Electrolyzed Acid Solution for the Control of Lameness with Digital Dermatitis in a Dairy Herd

2006 ◽  
Vol 59 (1) ◽  
pp. 35-39
Author(s):  
Akitoyo NISHIKAWA ◽  
Kiyoshi TAGUCHI ◽  
Hidetoshi HIGUCHI ◽  
Kimihiro SANO ◽  
Hajime NAGAHATA
Keyword(s):  
Acid Solution ◽  
Copper Sulfate ◽  
Dairy Herd ◽  
Digital Dermatitis

Detection of Turmeric in Foods by Rapid Fluorometric Method and by Improved Spot Test

1973 ◽  
Vol 56 (3) ◽  
pp. 626-628 ◽  
Author(s):  
Albert B Karasz ◽  
Frank De Cocco ◽  
Linda Bokus
Keyword(s):  
Acid Solution ◽  
Rapid Test ◽  
Egg Yolk ◽  
Spot Test ◽  
Fluorometric Method ◽  
Butanol Extract ◽  
Baked Goods ◽  
Acid Reagent ◽  
Water Saturated ◽  
Butanol Solution

Abstract The rapid test for turmeric is based on the fluorescence of curcumin, the principal pigment of turmeric. In a water-saturated n-butanol solution, its excitation maximum is 435 nm and the emission maximum is 520 nm. In the test described, which was applied to pickles, salad dressings, and baked goods, a sample is shaken with the butanol solvent and the filtered extract is scanned for a 520 nm peak on a spectrophotofluorometer that has been adjusted to give 100% scale deflection for a standard curcumin solution. Extracts of pickles and salad dressings are scanned directly. Extracts of enriched baked goods are treated to remove riboflavin fluorescence by partitioning both riboflavin and curcumin from butanol into a solution of 0.1N NaOH-15% NaCl, acidifying the latter with CH3COOH, reducing the riboflavin with Na2S2O4, and reextracting curcumin from acid solution into butanol for fluorometric scanning. No interference is caused by annatto, carotene, tartrazine, or egg yolk solids. A spot test may be performed on the butanol extract. The solution is evaporated to dryness, the residue is dissolved in a few drops of ethanol, and the spot test is performed with a boric acid reagent of considerably improved sensitivity.

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