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 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 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.

Die primäre Proteinstruktur von Stämmen des Tabakmosaikvirus

1963 ◽  
Vol 18 (12) ◽  
pp. 1032-1049 ◽  
Author(s):  
B. Wittmann-Liebold ◽  
H. G. Wittmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Amino Acid Sequences ◽  
Tryptic Peptides

The amino acid sequence of dahlemense, a naturally occuring strain of tobacco mosaic virus, has been determined and compared with that of the strain vulgare (Fig. 7). In this communication the experimental details are given for the elucidation of the amino acid sequences within two tryptic peptides with 65 amino acids.

Dual Functional Modification of Alkaline Amino Acids Induces the Self-Assembly of Cylinder-Like Tobacco Mosaic Virus Coat Proteins into Gear-Like Architectures

Small ◽  
2019 ◽  
Vol 15 (10) ◽  
pp. 1805543 ◽  
Author(s):  
Jian-Ting Zhang ◽  
Ranjith Kumar Kankala ◽  
Yi-Hao Zhou ◽  
Jin-Chen Dong ◽  
Ai-Zheng Chen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Self Assembly ◽  
The Self ◽  
Coat Proteins ◽  
Dual Functional ◽  
Functional Modification ◽  
Virus Coat

Charge Distribution and Surface Properties of the Tobacco Mosaic Virus 4-nm Central-Pore

2012 ◽  
Author(s):  
Nikolay I. Rodionov ◽  
Shalabh C. Maroo
Keyword(s):  
Amino Acids ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Charge Distribution ◽  
Electrostatic Potential ◽  
Model Organism ◽  
Surface Characteristics ◽  
Exterior Surface ◽  
Central Pore ◽  
Poisson Boltzmann Equation

The uniform distribution of charged amino acids along the exterior surface of the tobacco mosaic virus (TMV) along with its unusual structural stability over a large pH and temperature range has made it a model organism for inorganic deposition and nanostructure fabrication studies on biomolecules. However, the potential engineering applications of the virus’s central pore, which is about 300 nm long and 4 nm in diameter, has been overlooked. We aim to expand TMV applications by understanding the surface characteristics of its central pore. We have identified the set of amino acids and atoms that create the surface of the pore, mapped the partial charge distribution of the pore using AMBER9 force fields, and determined the electrostatic potential of the pore surface through Coulomb’s law and Poisson-Boltzmann Equation (PBE). Our analysis has revealed that the pore contains a dense helical distribution of negatively charged glutamic amino acid residues, which results in a strong negative electrostatic potential across the pore. This can potentially be used for water filtration by creating overlapping electric double layer within the central pore.

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