Modification of the protein molecule Communication 2. Attachment of amino acids and peptides at carboxy groups of the protein molecule

1958 ◽  
Vol 7 (2) ◽  
pp. 221-223
Author(s):  
K. T. Poroshin
Keyword(s):  
Amino Acids ◽  
Protein Molecule ◽  
Molecule Communication

Strahleninduzierte Aggregatbildung von Proteinen: Bindung von Aminosäuren an Myoglobin / Radiation-Induced Aggregation of Proteins: Binding of Amino Acids to Myoglobin

1978 ◽  
Vol 33 (3-4) ◽  
pp. 203-209 ◽  
Author(s):  
Vera Jakubick ◽  
Henry Delincée
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Molecule ◽  
Reactive Species ◽  
Radiation Induced ◽  
Induced Aggregation ◽  
Sulfur Containing ◽  
Tryptic Hydrolysis ◽  
Radioactive Spot

When myoglobin is irradiated in the presence of amino acids, the most radiation-reactive species, like the aromatic and sulfur-containing amino acids, will bind preferentially to the protein. The radiation-induced binding is strongly dependent on the concentration of protein and amino acid. Subsequent to irradiation of myoglobin in the presence of radioactively labelled tryptophan followed by tryptic hydrolysis, only a single radioactive spot was detected on the fingerprint. The binding of amino acids is thus not randomly distributed over the protein molecule but occurs at specific reactive sites.

A COLORIMETRIC METHOD FOR THE ESTIMATION OF REDUCING GROUPS IN MILK POWDERS

1945 ◽  
Vol 23b (3) ◽  
pp. 91-99 ◽  
Author(s):  
R. A. Chapman ◽  
W. D. McFarlane
Keyword(s):  
Amino Acids ◽  
Positive Reaction ◽  
Colorimetric Method ◽  
Protein Molecule ◽  
Potassium Ferricyanide ◽  
Potassium Iodate ◽  
Detection And Estimation ◽  
Reducing Activity ◽  
Colorimetric Estimation

A method has been developed for the detection and estimation of certain reducing groups in milk powders. The method is based on the reduction of potassium ferricyanide at 70 °C. and pH 5 and colorimetric estimation of ferric ferrocyanide. Titration with 2,6-dichlorophenolindophenol or potassium iodate failed to show any difference between fresh and stale milk powders. In contrast the ferricyanide test indicates much higher values in fresh powders than do the titration methods, and it also reveals a marked increase in samples that have developed stale, musty odours and flavours. Lactalbumin and casein show reducing activity that increases on heating. Of the amino acids tested, only tryptophane gives a positive reaction. It is concluded that the reducing groups are present in the protein molecule and become accessible on denaturation.

THE COMBINATION OF COPPER WITH AMINO ACIDS, PEPTIDES, AND PROTEINS

1959 ◽  
Vol 37 (1) ◽  
pp. 1033-1048
Author(s):  
J. F. Scaife
Keyword(s):  
Amino Acids ◽  
Nitrogen Atom ◽  
Dissociation Constant ◽  
Protein Molecule ◽  
Copper Salt ◽  
The Other ◽  
Dilute Solutions ◽  
Donor Nitrogen Atom ◽  
Donor Nitrogen ◽  
Made In

By equilibrating solutions containing amino acids, peptides, or proteins with the sparingly soluble copper salt malachite (CuCO3.Cu(OH)2), it has been possible to determine the amount of copper in the solutions complexed to these compounds, and the amount of free copper in the solutions in equilibrium with the complex. The dissociation constant for the copper–glycine complex has been estimated from the data obtained using this system. The nature of the complexes has been deduced both from chemical determinations of the bound copper, and from manometric measurements of the extent of complexing, made in bicarbonate buffers. The simple amino acids have been shown to form complexes of the type CuR2, which are appreciably dissociated in dilute solutions. The degree of complexing is influenced by the nature of the group R. Histidine, tryptophane, and other compounds containing more than one donor nitrogen atom are able to form more than one type of complex with copper. The participation of other nitrogen atoms in complexing is related to their basicities. Glycylglycine is able to bind approximately twice as much copper as glycine, but the other glycine peptides from triglycine to pentaglycine show a reduced and progressively decreasing ability to bind copper.The binding of copper to proteins differs from that of the amino acids, in that the amount of copper bound is independent of the concentration of protein present, for any given concentration of free copper. The several atoms of copper bound to each protein molecule were not all bound with the same affinity.

THE COMBINATION OF COPPER WITH AMINO ACIDS, PEPTIDES, AND PROTEINS

1959 ◽  
Vol 37 (8) ◽  
pp. 1033-1048 ◽  
Author(s):  
J. F. Scaife
Keyword(s):  
Amino Acids ◽  
Nitrogen Atom ◽  
Dissociation Constant ◽  
Protein Molecule ◽  
Copper Salt ◽  
The Other ◽  
Dilute Solutions ◽  
Donor Nitrogen Atom ◽  
Donor Nitrogen ◽  
Made In

By equilibrating solutions containing amino acids, peptides, or proteins with the sparingly soluble copper salt malachite (CuCO3.Cu(OH)2), it has been possible to determine the amount of copper in the solutions complexed to these compounds, and the amount of free copper in the solutions in equilibrium with the complex. The dissociation constant for the copper–glycine complex has been estimated from the data obtained using this system. The nature of the complexes has been deduced both from chemical determinations of the bound copper, and from manometric measurements of the extent of complexing, made in bicarbonate buffers. The simple amino acids have been shown to form complexes of the type CuR2, which are appreciably dissociated in dilute solutions. The degree of complexing is influenced by the nature of the group R. Histidine, tryptophane, and other compounds containing more than one donor nitrogen atom are able to form more than one type of complex with copper. The participation of other nitrogen atoms in complexing is related to their basicities. Glycylglycine is able to bind approximately twice as much copper as glycine, but the other glycine peptides from triglycine to pentaglycine show a reduced and progressively decreasing ability to bind copper.The binding of copper to proteins differs from that of the amino acids, in that the amount of copper bound is independent of the concentration of protein present, for any given concentration of free copper. The several atoms of copper bound to each protein molecule were not all bound with the same affinity.

Amino Acids in Developing Tissues of Xenopus laevis

Development ◽  
1956 ◽  
Vol 4 (4) ◽  
pp. 327-346
Author(s):  
E. M. Deuchar
Keyword(s):  
Amino Acids ◽  
Xenopus Laevis ◽  
Chemical Nature ◽  
Radioactive Tracer ◽  
Protein Molecule ◽  
Chick Embryos ◽  
Histological Differentiation ◽  
Tissue Specific ◽  
Tracer Techniques ◽  
Specific Antigens

Information about embryonic amino acids is of interest because of the possible light it throws on the differentiation of embryonic proteins. It is known from immunological work on amphibian and chick embryos (Cooper, 1946; Clayton, 1953; Ebert, 1950, 1952) that tissue-specific antigens are detectable before histological differentiation has taken place (Ten Cate & van Doorenmaalen, 1950). Although the chemical nature of antigenic differences is not yet properly known, recent evidence suggests that they may include differences in the number and arrangement of amino acids in N-terminal residues of the protein molecule (Porter & Sanger, 1948; McFadden & Smith, 1953; Putnam, 1953). For this reason, and on general grounds too, one may expect the formation of antigens in the embryo to be accompanied by altered arrangements of the proteinbound amino acids. Radioactive tracer techniques have made it possible to detect the uptake of amino acids into embryonic proteins (Waddington & Sirlin, 1954; Feldman & Waddington, 1955), but so far this information has not been related to the appearance of individual antigens.

scholarly journals NITROGEN METABOLISM OF NORMAL AND SARCOMATOUS FIBROBLASTS IN PURE CULTURES

1928 ◽  
Vol 48 (4) ◽  
pp. 533-547 ◽  
Author(s):  
Lillian E. Baker ◽  
Alexis Carrel
Keyword(s):  
Amino Acids ◽  
Protein Degradation ◽  
Nitrogen Metabolism ◽  
Degradation Products ◽  
Protein Molecule ◽  
Pure Cultures ◽  
Growth Promoting

1. Both normal and sarcomatous fibroblasts of the rat utilize many different fragments of the protein molecule for their growth in vitro. Alpha and beta proteoses have approximately equal growth-promoting power. 2. A mixture of peptones, peptides, and amino acids, containing a negligible quantity of proteose, produces a temporary proliferation of normal fibroblasts, and an unlimited multiplication of sarcomatous fibroblasts, provided these substances are derived from liver which contains products of unknown nature that complete the nutritive effect of the protein degradation products. 3. Amino acids contribute to the nutrition of the cells, but are unable without the addition of peptides or polypeptides to support their life. 4. The proteolytic products are more toxic to normal than to sarcomatous fibroblasts. The hypothesis is suggested that the greater acidity produced by the large glycolysis of the sarcomatous cells may account for this difference through altering the speed of action of protein synthetizing enzymes.

scholarly journals Intracellular Protein Biosynthesis: A Review

2020 ◽  
pp. 10-18
Author(s):  
Abdulsalam Alhalmi ◽  
Nafaa Alzobaidi ◽  
Amer Abdulrahman
Keyword(s):  
Amino Acids ◽  
Conformational Changes ◽  
Biological Function ◽  
Protein Biosynthesis ◽  
Genetic Material ◽  
Protein Molecule ◽  
Peptide Bond ◽  
Vital Role ◽  
Intracellular Protein ◽  
Specific Order

Proteins are macromolecules made up of many amino acids that linked together by peptide bond to make a protein molecule. The sequence and the number of amino acids determines each protein unique structure and specific function. Proteins play a vital role in living systems and play important biological functions. Biosynthesis of protein occur in our body cells in order to support the biological function in our body. Intracellular protein synthesis is a complex process that involve the transformation of information and instructions from a genetic material DNA inside the nucleus to form mRNA molecules that transferred to the cytoplasm and liked to the cytoplasmic ribosome. Subsequently, the m RNA and further encode a sequence of amino acid in a specific order and number to form a polypeptide chains that finally undergoes conformational changes and folding to form a particular structure protein. This review will focus on the tow consecutive stages of protein biosynthesis; transcription and translation, and their substage processes; initiation, elongation, and termination. Briefly, overview the role of protein in the biological function and the different types of protein structure.

LATTICE STRUCTURE AND DISTANCE MATRIX OF GENETIC CODE

2015 ◽  
Vol 23 (03) ◽  
pp. 485-504 ◽  
Author(s):  
NISHA GOHAIN ◽  
TAZID ALI ◽  
ADIL AKHTAR
Keyword(s):  
Amino Acids ◽  
Genetic Code ◽  
Lattice Structure ◽  
Real Life ◽  
Chemical Properties ◽  
Distance Matrix ◽  
Protein Molecule ◽  
Bond Number ◽  
Partial Ordering ◽  
Physico Chemical

The genetic code is the rule by which DNA stores the genetic information about formation of protein molecule. In this paper, a partial ordering is equipped on the genetic code and a lattice structure has been developed from it. The codon–anticodon interaction, hydrogen bond number and the chemical types of bases play an important role in the partial ordering. We have established some relations between the lattice structure of the genetic code and physico-chemical properties of amino acids. Taking into consideration the evolutionary importance of base positions in codons we have constructed a distance matrix for the amino acids. Further with a real life example we have demonstrated the relationship between frequently occurring mutations and codon distances.

scholarly journals An Algorithm for Computing Side Chain Conformational Variations of a Protein Tunnel/Channel

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2459
Author(s):  
Udeok Seo ◽  
Ku-Jin Kim ◽  
Beom Kang
Keyword(s):  
Amino Acids ◽  
Maximum Size ◽  
Protein Molecule ◽  
Divide And Conquer ◽  
Side Chain ◽  
Conformational Variations ◽  
Novel Method ◽  
Pass Through ◽  
Chain Conformations ◽  
Local Side

In this paper, a novel method to compute side chain conformational variations for a protein molecule tunnel (or channel) is proposed. From the conformational variations, we compute the flexibly deformed shapes of the initial tunnel, and present a way to compute the maximum size of the ligand that can pass through the deformed tunnel. By using the two types of graphs corresponding to amino acids and their side chain rotamers, the suggested algorithm classifies amino acids and rotamers which possibly have collisions. Based on the divide and conquer technique, local side chain conformations are computed first, and then a global conformation is generated by combining them. With the exception of certain cases, experimental results show that the algorithm finds up to 327,680 valid side chain conformations from 128~1233 conformation candidates within three seconds.

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