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 THE REACTIONS OF IODINE AND IODOACETAMIDE WITH NATIVE EGG ALBUMIN

1940 ◽  
Vol 23 (3) ◽  
pp. 321-331 ◽  
Author(s):  
M. L. Anson
Keyword(s):  
Amino Acids ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Reducing Power ◽  
Experimental Results ◽  
Ferricyanide Reduction ◽  
Native Form ◽  
Egg Albumin ◽  
Sh Groups ◽  
Sh Group

The following experimental results have been obtained. 1. Native egg albumin treated with iodine and then denatured no longer gives a nitroprusside test or reduces dilute ferricyanide in neutral Duponol PC solution. 2. More iodine is needed to abolish the ferricyanide reduction if the reaction between native egg albumin and iodine is carried out at pH 6.8 than if the reaction is carried out at pH 3.2. At pH 6.8 iodine reacts with tyrosine as well as with cysteine. 3. Cysteine and tryptophane are the only amino acids with reducing groups which are known to react with dilute iodine at pH 3.2 The reducing power of cysteine is abolished by the reaction with iodine, whereas the reducing power of tryptophane remains intact. Pepsin and chymotrypsinogen which contain tryptophane but not cysteine, do not react at all with dilute iodine at pH 3.2. 4. Native egg albumin treated with iodoacetamide at pH 9.0 and then denatured by Duponol PC reduces only 60 per cent as much dilute ferricyanide as egg albumin which has not been treated with iodoacetamide. 5. The SH group is the only protein reducing group which is known to react with iodoacetamide. The simplest explanation of the new observation that the SH groups of egg albumin can be modified by reactions with the native form of the protein is that the native egg albumin has free and accessible but relatively unreactive SH groups which can react with iodine and iodoacetamide despite the fact that they do not react with ferricyanide, porphyrindin, or nitroprusside. Preliminary experiments suggested by the results with egg albumin indicate that the tobacco mosaic virus is modified by iodine at pH 2.8 without being inactivated and that the tobacco mosaic and rabbit papilloma viruses are not inactivated by iodoacetamide at pH 8.0.

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.

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.

New approaches to the role of sulfhydryl groups in silver stainability of protein in grasshopper chromosomes

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 133-137 ◽  
Author(s):  
J. de la Torre ◽  
J. L. Bella ◽  
C. López-Fernandez ◽  
J. Gosálvez
Keyword(s):  
Silver Staining ◽  
Chemical Nature ◽  
Germ Line ◽  
Staining Technique ◽  
Sulfhydryl Groups ◽  
Sh Groups ◽  
New Approaches ◽  
Silver Staining Technique ◽  
Reduced State

Silver staining in somatic and germ line cells of the grasshopper Arcyptera fusca has been analyzed after a standard silver staining technique was used with pretreatments that included dithiothreitol and β-mercaptoethanol as reagents to maintain —SH groups in the reduced state. The results show that in some tissues, these pretreatments improve not only the silver staining of nucleolar masses but also the recognition of other silver spots associated with the chromatin. These observations are similar to those previously described for the effect of double-strength standard saline citrate on silver staining. The possible chemical nature of the protein groups responsible for the differential silver stainability and the role of saline citrate in the modification of argyrophylic proteins suggested previously are briefly discussed.Key words: Orthoptera, silver staining, sulfhydryl groups.

Stability of acetylcholinesterase in guanidine hydrochloride solution

1981 ◽  
Vol 59 (7) ◽  
pp. 551-555 ◽  
Author(s):  
Faizan Ahmad
Keyword(s):  
Molecular Weight ◽  
Guanidine Hydrochloride ◽  
Sedimentation Coefficient ◽  
Conformational State ◽  
Random Coil ◽  
Aromatic Residues ◽  
Activity Measurements ◽  
Irreversible Unfolding ◽  
Hydrochloride Solution ◽  
Circular Dichroic

The irreversible unfolding of acetylcholinesterase (acetylcholine hydrolyase, EC 3.1.1.7) by guanidine hydrochloride was studied by difference spectral, circular dichroic, and enzyme activity measurements. At pH 7.0 and in 1.1 M denaturant solution, a conformational state in which enzyme is completely inactive was detected. It is identical to the native enzyme as far as sedimentation coefficient and molecular weight are concerned, but differs from the native molecule by a slight loss in secondary structure and by a small perturbation of aromatic residues. Acetylcholinesterase in concentrated guanidine hydrochloride solution containing β-mercaptoethanol dissociates and exists as a random coil of molecular weight 68 000.

Brillouin Light Scattering In Guanidine Hydrochloride Solution

2010 ◽  
Author(s):  
A. V. Svanidze ◽  
I. P. Koludarov ◽  
A. I. Fedoseev ◽  
S. G. Lushnikov ◽  
Seiji Kojima ◽  
...  
Keyword(s):  
Light Scattering ◽  
Guanidine Hydrochloride ◽  
Brillouin Light Scattering ◽  
Hydrochloride Solution
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