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.

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.

Effect of substituents at the proton-donor nitrogen atom on an intramolecular hydrogen bond of type NH...O

1974 ◽  
Vol 15 (3) ◽  
pp. 353-356
Author(s):  
L. N. Kurkovaskaya ◽  
I. L. Radushnova ◽  
N. N. Shapet'ko ◽  
S. M. Kvitko ◽  
Yu. S. Andreichikov ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Nitrogen Atom ◽  
Intramolecular Hydrogen Bond ◽  
Proton Donor ◽  
Effect Of Substituents ◽  
Donor Nitrogen Atom ◽  
Donor Nitrogen ◽  
Intramolecular Hydrogen

2-Isoxazolinium Salts and 3-Isoxazolines: Exploratory Chemistry and Uses for the Synthesis of Branched Amino Polyols and Amino Acids

2010 ◽  
Vol 65 (7) ◽  
pp. 821-832 ◽  
Author(s):  
Volker Jäger ◽  
Wolfgang Frey ◽  
Yaser Bathich ◽  
Sunitha Shiva ◽  
Mohammad Ibrahim ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nitrogen Atom ◽  
The Other ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
Initial Attack ◽  
Nitrile Oxides ◽  
Hydride Reduction ◽  
Potential Applications ◽  
Electrophilic Reagents

2-Isoxazolines represent a well known class of heterocycles, readily accessible in particular by 1,3-dipolar cycloaddition of nitrile oxides to alkenes. 2-Isoxazolines are easily transformed into 2- isoxazolinium salts by N-methylation, and further into 3-isoxazolines by deprotonation. In contrast to the parent system, less is known concerning the chemistry of the derived classes, and potential applications in synthesis. - 2-Isoxazolinium salts, due to their iminium part, are prone to the attack of nucleophiles, and examples for this, addition of hydride (reduction) and C-nucleophiles like methylmagnesium bromide, cyanide, methane nitronate, and malonate are given. With these adducts, syntheses of β - and α-amino acids with OH-containing side chains have been effected. The cyanide products also are useful as precursors of branched, unsymmetrical 1,2-diamino polyols. - On the other hand, 3-isoxazolines due to their oxy-enamine part, represent species with nucleophilic sites and therefore react with electrophilic reagents. Examples given are [3+2] cycloadditions with nitrile oxides, [2+2] cycloadditions with dimethyl acetylenedicarboxylate, and [2+1] cycloaddition in the form of epoxidation which, however, led to a dihydro-1,3-oxazine nitrone by initial attack at the nitrogen atom, in an unprecedented oxidation/N-dealkylation/rearrangement sequence.

scholarly journals High Hydrostatic Pressure as a Tool to Reduce Formation of Biogenic Amines in Artisanal Spanish Cheeses

Foods ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 137 ◽  
Author(s):  
Diana Espinosa-Pesqueira ◽  
Maria Hernández-Herrero ◽  
Artur Roig-Sagués
Keyword(s):  
Amino Acids ◽  
Hydrostatic Pressure ◽  
Biogenic Amines ◽  
High Hydrostatic Pressure ◽  
Free Amino ◽  
Raw Milk ◽  
The Other ◽  
Microbial Counts ◽  
Control Samples ◽  
Made In

Two artisanal varieties of cheese made in Spain, one made of ewes’ raw milk and the other of goats’ raw milk were selected to evaluate the effect of a high hydrostatic pressure (HHP) treatment at 400 MPa during 10 min at 2 °C on the formation of biogenic amines (BA). These conditions were applied at the beginning of the ripening (before the 5th day; HHP1) and in the case of ewes’ milk cheeses also after 15th days (HHP15). BA formation was greatly influenced by HHP treatments in both types of cheese. HHP1 treatments significantly reduced the amounts of BA after ripening, being tyramine and putrescine the most affected BA in goats’ milk cheeses and tyramine and cadaverine in ewes’ milk cheeses. The BA reduction in the HHP1 samples could be explained by the significant decrease in microbiological counts, especially in the LAB, enteroccocci and enterobacteria groups at the beginning of ripening. The proteolysis in these samples was also affected reducing the amount of free amino acids. Although proteolysis in ewes’ milk cheeses HHP15 was similar than in control samples a reduction of BA was observed probably because the decrease caused on microbial counts.

Novel organic sensitizer based on directly linked oligothiophenes to donor nitrogen atom for efficient dye-sensitized solar cells

2014 ◽  
Vol 193 ◽  
pp. 102-109 ◽  
Author(s):  
Akhil Gupta ◽  
Melissa Kelson ◽  
Vanessa Armel ◽  
Wanchun Xiang ◽  
Ante Bilic ◽  
...  
Keyword(s):  
Solar Cells ◽  
Nitrogen Atom ◽  
Dye Sensitized Solar Cells ◽  
Dye Sensitized ◽  
Donor Nitrogen Atom ◽  
Donor Nitrogen ◽  
Sensitized Solar Cells ◽  
Organic Sensitizer

scholarly journals Infra-red absorption spectra of some amino compounds

1941 ◽  
Vol 177 (971) ◽  
pp. 447-456 ◽  
Keyword(s):  
Molecular Structure ◽  
Amino Acids ◽  
Experimental Evidence ◽  
Absorption Spectra ◽  
The Other ◽  
Close Similarity ◽  
Amino Compounds ◽  
Infra Red ◽  
The One ◽  
Made In

An investigation of the infra-red absorption spectra of five amino compounds (glycine, diketopiperazine, tetramethyl-diketopiperazine, glycylglycine and urea) has been made in the region 2-8-3-6 μ . The substances were used in the form of thin crystalline layers deposited on quartz windows. The spectra are discussed with regard to the molecular structure of the compounds under consideration. The number and position of the N—H frequencies in glycine and glycyl-glycine are in agreement with the assumption that these two molecules are in the zwitterion form in the crystal. The close similarity between the spectra of diketopiperazine and tetramethyldiketopiperazine on the one hand, and the amino acids and urea on the other, proves that no lactam-lactim interchange occurs in diketopiperazine and its derivative. Both compounds are shown to possess a centre of symmetry. It follows from the experimental evidence that in all the substances investigated resonance between the C—N and 0 = 0 bonds takes place.

Plasminogen-Plasmin System IX. Specific Binding of Tranexamic Acid to Plasmin

1975 ◽  
Vol 33 (03) ◽  
pp. 573-585 ◽  
Author(s):  
Masahiro Iwamoto
Keyword(s):  
Tranexamic Acid ◽  
Affinity Chromatography ◽  
Dissociation Constant ◽  
Factor Xiii ◽  
Specific Binding ◽  
The Other ◽  
Inhibitory Mechanism ◽  
Binding Studies ◽  
Similar Affinity ◽  
Fibrin Structure

SummaryInteractions between tranexamic acid and protein were studied in respect of the antifibrinolytic actions of tranexamic acid. Tranexamic acid did neither show any interaction with fibrinogen or fibrin, nor was incorporated into cross-linked fibrin structure by the action of factor XIII. On the other hand, tranexamic acid bound to human plasmin with a dissociation constant of 3.5 × 10−5 M, which was very close to the inhibition constant (3.6 × 10−5 M) for this compound in inhibiting plasmin-induced fibrinolysis. The binding site of tranexamic acid on plasmin was not the catalytic site of plasmin, because TLCK-blocked plasmin also showed a similar affinity to tranexamic acid (the dissociation constant, 2.9–4.8 × 10−5 M).In the binding studies with the highly purified plasminogen and TLCK-plasmin preparations which were obtained by affinity chromatography on lysine-substituted Sepharose, the molar binding ratio was shown to be 1.5–1.6 moles tranexamic acid per one mole protein.On the basis of these and other findings, a model for the inhibitory mechanism of tranexamic acid is presented.

Pengoptimalan Air Leri dalam Pembuatan Sabun Pembersih Wajah Alami yang Ekonomis

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Rahmawati Rahmawati ◽  
Trimayasari Trimayasari ◽  
Ghozali Akhmad Mustaqim ◽  
Wening Dwi Prastiwi ◽  
Emas Agus Prastyo Wibowo
Keyword(s):  
Amino Acids ◽  
Fine Particles ◽  
Hard Water ◽  
Essential Amino Acids ◽  
Ultraviolet Rays ◽  
Starch Granules ◽  
Facial Skin ◽  
Skin Cells ◽  
The Face ◽  
Made In

AbstractSoap facial cleanser is needed to keep the facial skin to keep them clean and healthy. The purpose of this study to make soap cleanser with natural materials such as hard water deposits leri. This is because the use of leri water starch or starch granules of fine particles contained in water leri dansel dust can shed the dead skin on the face because of the essential amino acids contained can regenerate skin cells. In addition, water leri can brighten the face because the leri water oryzanol contain substances that can update the development and formation of the pigment melanin, which is effectively to ward off ultraviolet rays. The process of making soap using the principle of saponification reaction, namely the reaction between the oil and the KOH/NaOH. Facial cleansing soap made in this study is solid soap. Based on the results of quality test, soap solid leri water has a pH of 11.1, saponification number is 33, the water content of 46% as well as respondents to the test aspects of aroma and foam shows good results so this water leri treatment can be an alternative solution to prevent the use of soap facial cleansers that contain harmful chemicals. Keywords: air leri, soap cleanser, saponification  AbstrakSabun pembersih wajah sangat diperlukan untuk menjaga kulit wajah agar tetap bersih dan sehat. Tujuan dari penelitian ini untuk membuat sabun pembersih wajah dengan bahan alami berupa endapan air leri. Penggunaan air leri ini dikarenakan butiran partikel starch atau pati halus yang terdapat dalam air leri dapat merontokkan debu dansel kulit mati pada wajah karena asam amino esensial yang terkandung dapat meregenerasi sel-sel kulit. Selain itu, air leri dapat mencerahkan wajah karena air leri mengandung zat oryzanol yang dapat memperbarui perkembangan dan pembentukan pigmen melanin, yang efektif guna menangkal sinar ultraviolet. Proses pembuatan sabun menggunakan prinsip reaksi saponifikasi, yaitu reaksi antara minyak dan KOH/NaOH. Sabun pembersih wajah yang dibuat dalam penelitian ini ialah sabun padat. Berdasarkan hasil uji mutu, sabun air leri padat memiliki pH 11,1, angka penyabunan sebesar 33 kadar air 46 kadar air 46 % serta uji responden terhadap aspek aroma dan busa yang menunjukkan hasil cukup baik sehingga pengolahan air leri ini dapat menjadi solusi alternative untuk mencegah penggunaan sabun pembersih wajah yang mengandung bahan kimia berbahaya. Kata kunci: air leri, sabun pembersih wajah, saponifikasi 

On the Future of the Financial Redistribution across Member States in the EU

2006 ◽  
Vol 56 (1) ◽  
pp. 1-43
Author(s):  
Sándor Richter
Keyword(s):  
Value Added ◽  
The Other ◽  
Current Debate ◽  
Member States ◽  
New Member States ◽  
Financial Position ◽  
Cross Member ◽  
Expenditure Structure ◽  
The Eu ◽  
Made In

The order and modalities of cross-member state redistribution as well as the net financial position of the member states are one of the most widely discussed aspects of European integration. The paper addresses selected issues in the current debate on the EU budget for the period 2007 to 2013 and introduces four scenarios. The first is identical to the European Commission's proposal; the second is based on reducing the budget to 1% of the EU's GNI, as proposed by the six net-payer countries, while maintaining the expenditure structure of the Commission's proposal. The next two scenarios represent radical reforms: one of them also features a '1% EU GNI'; however, the expenditures for providing 'EU-wide value-added' are left unchanged and it is envisaged that the requisite cuts will be made in the expenditures earmarked for cohesion. The other reform scenario is different from the former one in that the cohesion-related expenditures are left unchanged and the expenditures for providing 'EU-wide value-added' are reduced. After the comparison of the various scenarios, the allocation of transfers to the new member states in terms of the conditions prevailing in the different scenarios is analysed.

Physical and Mechanical Properties of Tenun Pahang Fabrics using Alternative Yarns

2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Silk Fabrics ◽  
Recovery Angle ◽  
Made In

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.

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