THE SELECTIVE DEGRADATION OF WHEAT GLUTEN

1955 ◽  
Vol 33 (8) ◽  
pp. 1295-1303 ◽  
Author(s):  
L. Wiseblatt ◽  
L. Wilson ◽  
W. B. McConnell
Keyword(s):  
Strong Association ◽  
Average Molecular Weight ◽  
Wheat Gluten ◽  
Strong Acid ◽  
Terminal Group ◽  
Pressure Measurements ◽  
Amino Groups ◽  
Peptide Bonds ◽  
Selective Degradation ◽  
Chemical Cross Linking

A method believed to hydrolyze peptide bonds of proteins selectively at the amino groups of serine was used to obtain polypeptides from wheat gluten. The procedure involved the use of strong acid and introduced appreciable amounts of sulphur into the products possibly as sulphonic acid groups. Most of the serine appeared at the amino termini of the peptides. The peptides displayed a striking electrophoretic homogeneity which may at least in part be accounted for by the acquired acid groups. Osmotic pressure measurements indicated an average molecular weight near 20,000 and terminal group estimates indicate that each molecule contained several N-terminal serine residues. There appeared to be strong association or chemical cross linking between peptide chains of the degraded gluten.

scholarly journals Safety Assessment of Hydrolyzed Wheat Protein and Hydrolyzed Wheat Gluten as Used in Cosmetics

2018 ◽  
Vol 37 (1_suppl) ◽  
pp. 55S-66S ◽  
Author(s):  
Christina Burnett ◽  
Wilma F. Bergfeld ◽  
Donald V. Belsito ◽  
Ronald A. Hill ◽  
Curtis D. Klaassen ◽  
...  
Keyword(s):  
Safety Assessment ◽  
Expert Panel ◽  
Average Molecular Weight ◽  
Wheat Gluten ◽  
Safety Data ◽  
Hypersensitivity Reactions ◽  
Wheat Protein ◽  
Laboratory Studies ◽  
Immediate Hypersensitivity

The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) reviewed the product use, formulation, and safety data on hydrolyzed wheat protein and hydrolyzed wheat gluten, which function as skin- and hair-conditioning agents. The Panel determined that data from clinical and laboratory studies were sufficient to demonstrate that these ingredients will not elicit type 1 immediate hypersensitivity reactions in sensitized individuals and will not induce sensitization when the polypeptide lengths of the hydrolysates do not exceed 30 amino acids. The Panel concluded that hydrolyzed wheat gluten and hydrolyzed wheat protein are safe for use in cosmetics when formulated to restrict peptides to an average molecular weight of 3,500 Da or less.

scholarly journals Thermal Synthesis of Polypeptides from N-Butyloxycarbonyl Oligopeptides Containing Aspartyl Residue at C-Terminus

2017 ◽  
Vol 2017 ◽  
pp. 1-16
Author(s):  
Toratane Munegumi ◽  
Takafumi Yamada
Keyword(s):  
Aspartic Acid ◽  
Organic Synthesis ◽  
Prebiotic Chemistry ◽  
Average Molecular Weight ◽  
Carboxyl Terminus ◽  
Peptide Bonds ◽  
Thermal Synthesis ◽  
Thermal Reactions ◽  
C Terminus ◽  
Aspartyl Residue

The thermal reactions of amino acids have been investigated for pure organic synthesis, materials preparation in industry, and prebiotic chemistry. N-t-Butyloxycarbonyl aspartic acid (Boc-Asp) releases 2-butene and carbon dioxide upon heating without solvents. The resulting mixture of the free molten aspartic acid was dehydrated to give peptide bonds. This study describes the thermal reactions of N-t-butyloxycarbonyl peptides (Boc-Gly-L-Asp, Boc-L-Ala-L-Asp, Boc-L-Val-L-Asp, and Boc-Gly-Gly-L-Asp) having an aspartic residue at the carboxyl terminus. The peptides were deprotected upon heating at a constant temperature between 110 and 170°C for 1 to 24 h to afford polypeptides in which the average molecular weight reached 7800.

scholarly journals Novel Resins for Efficient Desalination

Substantia ◽  
2021 ◽  
pp. 39-48
Author(s):  
Tanita Gettongsong ◽  
Mojtaba Taseidifar ◽  
Richard M. Pashley ◽  
Barry W. Ninham
Keyword(s):  
Chemical Properties ◽  
Strong Acid ◽  
Electrolyte Solutions ◽  
Strong Base ◽  
Ph Values ◽  
Surface Charging ◽  
Physico Chemical ◽  
Electrical Conductivities ◽  
Acid And Base ◽  
Chemical Cross Linking

This paper reports the synthesis and properties of new polymer resins containing strong acid and base groups for optimising applications in desalination. Several polyampholytic gels were synthesised with a ratio of 1:1 of strong acid (sulphonate) and strong base (quaternary ammonium) groups and a zwitterionic resin with a 1:1 strong acid and base ratio. The physico-chemical properties of these highly charged resins were studied in electrolyte solutions over a range of pH values, in particular: effects of chemical cross-linking, water and electrolyte swelling; bulk electrical conductivities and surface charging properties in different pH values. The results from absorption of NaCl showed that the resins have considerable potential for more effective desalination than other resin-based techniques.

Weitere Untersuchungen zur Aminosäuresequenz des Melittins, II.

1969 ◽  
Vol 24 (4) ◽  
pp. 415-418 ◽  
Author(s):  
Joachim Jentsch
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
High Specificity ◽  
Bee Venom ◽  
Side Chains ◽  
Amino Groups ◽  
Crotalus Atrox ◽  
Peptide Bonds ◽  
Rattlesnake Venom

Degradation of melittin with α-Protease from Crotalus atrox venom (rattlesnake) confirmed the amino acid sequence of the toxic main peptide from bee venom. Hydrolysis occured mainly at the peptide bonds whose amino groups were provided by hydrophobic side chains such as valine, leucine and isoleucine bonds. However, on the contrary one glutamine bond was cleaved. Neverthelness, regarding the relatively high specificity, rattlesnake venom protease may be a valuable reagent for further sequence studies.

scholarly journals Osmotic Pressure Measurements on Insulin: Anomalous Results Indicate that the Monomer is Preferentially Adsorbed

1986 ◽  
Vol 39 (4) ◽  
pp. 319 ◽  
Author(s):  
Peter D Jeffrey
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Osmotic Pressure ◽  
Hydrophobic Interactions ◽  
Average Molecular Weight ◽  
Adsorption Properties ◽  
Sedimentation Equilibrium ◽  
Pressure Measurements ◽  
Number Average Molecular Weight ◽  
Adsorption Analysis

The concentration dependence of the number average molecular weight of insulin at pH 2, ionic strength 0'05, and 20�C as determined by osmotic pressure measurements indicates that the .hormone is a homogeneous protein of molecular weight close to that of the dimer. Since sedimentation equilibrium experiments confirm what is well known, namely that insulin is a self-associating protein dissociating to monomer under these conditions, an explanation for the anomaly was sought in the possible loss of protein from solution by adsorption. Analysis of the results strongly supports this conclusion and consideration of the adsorption properties of insulin in terms of hydrophobic interactions shows them to be consistent with the behaviour of insulin as a self-associating protein. The monomer appears to be the primary molecular species responsible for insulin adsorption.

Synthesis of pressinoic acid by enzymatically catalyzed formation of peptide bonds

1986 ◽  
Vol 51 (6) ◽  
pp. 1352-1360 ◽  
Author(s):  
Václav Čeřovský
Keyword(s):  
Methyl Esters ◽  
Sulfhydryl Group ◽  
Carboxyl Groups ◽  
Amino Groups ◽  
Peptide Bonds ◽  
Fragment Condensation

Three fully enzymatic syntheses of the 1-6 vasopressin hexapeptide were investigated using papain, α-chymotrypsin and thermolysin. Best results were obtained with thermolysin in the 2 + 4 fragment condensation. The α-chymotrypsin-catalyzed 3 + 3 condensation is less advantageous and the 4 + 2 condensation with papain gave only low yield. Using the mentioned enzymes, further fragments of vasopressin molecule were prepared. Amino groups were protected with benzoylcarbonyl or tert-butyloxycarbonyl groups, carboxyl groups as phenylhydrazides or methyl esters, and the cysteine sulfhydryl group as the benzyl derivate. The tyrosine hydroxyl was not protected.

Enzymatically catalyzed synthesis of oxytocin fragments 1-6 and 7-9

1985 ◽  
Vol 50 (12) ◽  
pp. 2775-2782 ◽  
Author(s):  
Václav Čeřovský ◽  
Karel Jošt
Keyword(s):  
Ethyl Ester ◽  
Sulfhydryl Group ◽  
Amino Groups ◽  
Equimolar Ratio ◽  
Peptide Bonds ◽  
The Given

Papain, α-chymotrypsin, thermolysin and elastase were utilized in the synthesis of peptide bonds of the protected oxytocin nonapeptide, except the S-benzylcysteine-proline bond. Amino groups were protected with benzyloxycarbonyl or tert-butyloxycarbonyl groups, carboxy groups as ethyl ester, phenylhydrazides or amides. The cysteine sulfhydryl group was blocked with the benzyl group whereas the tyrosine hydroxyl was unprotected. Most of the fragments were synthesized in satisfactory yields using an equimolar ratio of both reaction components and minimal (experimentally determined) amount of the given enzyme.

Molecular weight of an extremely hydrophobic protein, zein, in dimethylformamide and in formamide

1976 ◽  
Vol 54 (2) ◽  
pp. 196-199 ◽  
Author(s):  
Laurence A. Danzer ◽  
E. Douglas Rees
Keyword(s):  
Molecular Weight ◽  
Osmotic Pressure ◽  
Protein Concentration ◽  
Average Molecular Weight ◽  
Water Soluble ◽  
Nonaqueous Solvents ◽  
Pressure Measurements ◽  
Number Average Molecular Weight ◽  
Commercial Preparation ◽  
Made In

Both alpha zein purified from a commercial preparation and beta zein prepared fresh from corn are soluble in the nonaqueous solvents formamide and dimethylformamide; in this regard zein resembles water soluble proteins such as insulin, ribonuclease, and lysozyme. On the basis of osmotic pressure measurements made in both formamide and dimethylformamide, alpha zein has a number average molecular weight of 21 000 – 24 000 daltons and shows no tendency to aggregate or dissociate. Beta zein exists in an aggregated state (dimer and higher forms) in dimethylformamide. Formamide dissociates the beta zein dimer into monomer units but aggregation to higher species occurs with increasing protein concentration.

scholarly journals Osmotic Pressure and Diffusion Constant of Protein Extracted From Wool With Urea-Bisulphite Solutions

1953 ◽  
Vol 6 (4) ◽  
pp. 630 ◽  
Author(s):  
JA Friend ◽  
IJ O'donnell
Keyword(s):  
Molecular Weight ◽  
Osmotic Pressure ◽  
Soluble Protein ◽  
Average Molecular Weight ◽  
Diffusion Constant ◽  
Pressure Measurements ◽  
Number Average Molecular Weight ◽  
And Diffusion

Wool treated with 8M urea, OAM NaHS03 at 60�C forms a polydisperse soluble protein of number-average molecular weight 12,000-16,000 as deduced from osmotic pressure measurements. The values lie within this range whether 20 or 70 per cent. of the wool is dissolved. The pH of measurement or of extraction has no effect on the molecular weight of the solute over the range 5.6-8.0. 'The diffusion constant, Dzo, W' of the soluble protein is 4.5 X 10-7 cm2sec-1 .

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