scholarly journals The effect of iodination of particular tyrosine residues on the hormonal activity of insulin

1972 ◽  
Vol 126 (1) ◽  
pp. 123-131 ◽  
Author(s):  
C. J. Garratt ◽  
D. M. Harrison ◽  
Margaret Wicks
Keyword(s):  
Receptor Site ◽  
Target Tissue ◽  
Tyrosine Residue ◽  
Hormonal Activity ◽  
Tyrosine Residues ◽  
A Chain ◽  
The Individual ◽  
Adipose Cells

Insulin dissolved in aqueous or methanolic buffer was iodinated to give preparations containing an average of between one and five iodine atoms per insulin monomer. The resultant preparations were fragmented in various ways and the ratio of tyrosine to monoiodotyrosine and di-iodotyrosine was determined in each fragment. This has allowed the distribution of iodine between the combined A-chain tyrosine residues and the individual B-chain tyrosine residues to be determined. The hormonal activity of each of these iodinated insulin preparations was measured from their effect on the production of 14CO2 from [1-14C]glucose by isolated adipose cells. The results were interpreted as meaning that the iodination of tyrosine residue A19 or B16 leads to the inactivation of insulin. Speculations are made about the nature of an interaction between insulin and a receptor site on the target tissue.

PREPARING PUBLIC SERVANTS IN EUROPEAN COUNTRIES: ARCHETYPAL APPROACH

2018 ◽  
Vol 1 (14) ◽  
pp. 255-263
Author(s):  
Oleh Ivanovich Rohulskyi
Keyword(s):  
Public Administration ◽  
Public Service ◽  
Professional Training ◽  
European Countries ◽  
Anglo Saxon ◽  
Public Servants ◽  
German Model ◽  
Managerial Positions ◽  
A Chain ◽  
The Individual

The article describes the main components of the institutional framework of an archetypical approach to public administration. It is determined that the system of preparation of public servants is based on a chain of universal foundations of archetype, in particular, it is influenced by the principle of formation of personnel in the public service, formed on the basis of public opinion. Based on two basic principles relating to admission to public service, three basic models of training civil servants in the European country are defined: German. French and Anglo-Saxon. We analyze each of the models and define the archetypes that influenced their formation and development. The advantages of each model are determined, in particular, the benefits are: the German model of training managers is the balancing between the theoretical knowledge and practical skills that a public servant receives during training, but as a disadvantage one can distinguish the orientation of preparation for legal orientation, which limits the ability to hold managerial positions for many employees The French model of professional training of public servants should include a well-balanced understanding of tasks, namely: decentralization and territorial organization of public services, communication, support of territorial communities, in-depth knowledge and understanding of the need for cooperation with institutions of the European Commonwealth, high-quality human resource management and orientation towards environmentally friendly innovations, such a model of training of public servants is holistic, costly and effective; The Anglo-Saxon model of training of public servants is its orientation towards the implementation of the concept of public administration and the individual approach to employee training, taking into account all the specifics of its activities, providing for the formation of personnel capable of solving specific problems. It is concluded that today in most European countries dominated by mixed models that include elements of different models.

scholarly journals An MEG Study of Picture Naming

1998 ◽  
Vol 10 (5) ◽  
pp. 553-567 ◽  
Author(s):  
Willem J. M. Levelt ◽  
Peter Praamstra ◽  
Antje S. Meyer ◽  
Päivi Helenius ◽  
Riitta Salmelin
Keyword(s):  
Picture Naming ◽  
Time Windows ◽  
Naming Latency ◽  
Cortical Activation ◽  
Response Patterns ◽  
Phonological Encoding ◽  
A Chain ◽  
Wernicke’S Area ◽  
The Individual ◽  
The Right

The purpose of this study was to relate a psycholinguistic processing model of picture naming to the dynamics of cortical activation during picture naming. The activation was recorded from eight Dutch subjects with a whole-head neuromagnetometer. The processing model, based on extensive naming latency studies, is a stage model. In preparing a picture's name, the speaker performs a chain of specific operations. They are, in this order, computing the visual percept, activating an appropriate lexical concept, selecting the target word from the mental lexicon, phonological encoding, phonetic encoding, and initiation of articulation. The time windows for each of these operations are reasonably well known and could be related to the peak activity of dipole sources in the individual magnetic response patterns. The analyses showed a clear progression over these time windows from early occipital activation, via parietal and temporal to frontal activation. The major specific findings were that (1) a region in the left posterior temporal lobe, agreeing with the location of Wernicke's area, showed prominent activation starting about 200 msec after picture onset and peaking at about 350 msec, (i.e., within the stage of phonological encoding), and (2) a consistent activation was found in the right parietal cortex, peaking at about 230 msec after picture onset, thus preceding and partly overlapping with the left temporal response. An interpretation in terms of the management of visual attention is proposed.

Migration of protons in a chain of tyrosine residues

2001 ◽  
Vol 84 (4) ◽  
pp. 409-415 ◽  
Author(s):  
V. E. Stefanov ◽  
A. A. Tulub
Keyword(s):  
Tyrosine Residues ◽  
A Chain

The ultrastructure of Methanothrix concilii, a mesophilic aceticlastic methanogen

1986 ◽  
Vol 32 (9) ◽  
pp. 703-710 ◽  
Author(s):  
Terry J. Beveridge ◽  
Girish B. Patel ◽  
Bob J. Harris ◽  
G. Dennis Sprott
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Circular Plates ◽  
A Cell ◽  
Granular Matrix ◽  
A Chain ◽  
The Individual

Methanothrix concilii strain GP6 consists of a chain of rod-shaped cells, ca. 2.5 μm in length and 0.8 μm in width, which are encased in a tubular proteinaceous sheath. The sheath is composed of annular hoops, ca. 8.0 nm wide and 9.0 nm thick, which are stacked together to form the tube. The ends of the sheath, and therefore the cell filament, are blocked by single, multilayered, 13.5 nm thick, circular plates, designated as "spacer plugs," which contain a series of concentric rings; these also separate the individual cells within each filament. Each cell is therefore bounded by a tubular section of sheath and two spacer plugs. Completely encapsulating each cell, and lying between the sheath and cell, is an amorphous granular matrix. Overlying the plasma membrane and surrounding each protoplast is a thin veil of material which resembles a cell wall, but which is unable to maintain the rod shape when cells are extruded from the sheath.

scholarly journals Probing the active site residues in aromatic donor oxidation in horseradish peroxidase: involvement of an arginine and a tyrosine residue in aromatic donor binding

1996 ◽  
Vol 314 (3) ◽  
pp. 985-991 ◽  
Author(s):  
Subrata ADAK ◽  
Abhijit MAZUMDER ◽  
Ranajit K. BANERJEE
Keyword(s):  
Active Site ◽  
Native Enzyme ◽  
Tyrosine Residue ◽  
Tyrosine Residues ◽  
First Order ◽  
First Order Kinetics ◽  
Aromatic Donor ◽  
Pseudo First Order ◽  
Modified Enzyme ◽  
Compound Ii

The plausible role of arginine and tyrosine residues at the active site of horseradish peroxidase (HRP) in aromatic donor (guaiacol) oxidation was probed by chemical modification followed by characterization of the modified enzyme. The arginine-specific reagents phenylglyoxal (PGO), 2,3-butanedione and 1,2-cyclohexanedione all inactivated the enzyme, following pseudo-first-order kinetics with second-order rate constants of 24 M-1·min-1, 0.8 M-1·min-1 and 0.54 M-1·min-1 respectively. Modification with tetranitromethane, a tyrosine-specific reagent, also resulted in 50% loss of activity following pseudo-first-order kinetics with a second-order rate constant of 2.0 M-1·min-1. The substrate, H2O2, and electron donors such as I- and SCN- offered no protection against inactivation by both types of modifier, whereas the enzyme was completely protected by guaiacol or o-dianisidine, an aromatic electron donor (second substrate) oxidized by the enzyme. These studies indicate the involvement of arginine and tyrosine residues at the aromatic donor site of HRP. The guaiacol-protected phenylglyoxal-modified enzyme showed almost the same binding parameter (Kd) as the native enzyme, and a similar free energy change (∆G´) for the binding of the donor. Stoicheiometric studies with [7-14C]phenylglyoxal showed incorporation of 2 mol of phenylglyoxal per mol of enzyme, indicating modification of one arginine residue for complete inactivation. The difference absorption spectrum of the tetranitromethane-modified against the native enzyme showed a peak at 428 nm, characteristic of the nitrotyrosyl residue, that was abolished by treatment with sodium dithionite, indicating specific modification of a tyrosine residue. Inactivation stoicheiometry showed that modification of one tyrosine residue per enzyme caused 50% inactivation. Binding studies by optical difference spectroscopy indicated that the arginine-modified enzyme could not bind guaiacol at all, whereas the tyrosine-modified enzyme bound it with reduced affinity (Kd 35 mM compared with 10 mM for the native enzyme). Both the modified enzymes, however, retained the property of the formation of compound II (one-electron oxidation state higher than native ferriperoxidase) with H2O2, but reduction of compound II to native enzyme by guaiacol did not occur in the PGO-modified enzyme, owing to lack of binding. No non-specific change in protein structure due to modification was evident from circular dichroism studies. We therefore suggest that the active site of HRP for aromatic donor oxidation is composed of an arginine and an adjacent tyrosine residue, of which the former plays an obligatory role in aromatic donor binding whereas the latter residue plays a facilitatory role, presumably by hydrophobic interaction or hydrogen bonding.

Kinetics of the hydrogen/oxygen reaction II. The explosion region in salt- and alkali-coated vessels

1952 ◽  
Vol 211 (1104) ◽  
pp. 86-95 ◽  
Keyword(s):  
Mixture Composition ◽  
Spontaneous Ignition ◽  
Vessel Size ◽  
First Order ◽  
Wide Range ◽  
Chain Theory ◽  
A Chain ◽  
The Individual ◽  
Kinetics Of ◽  
Oxygen Reaction

The first, second and third explosion limits for the hydrogen/oxygen reaction have been examined over a wide range of temperature, mixture composition, vessel size and wall coating. An expression has been derived from general chain theory which can account for the observed features of the complete explosion region. It includes and relates previously given expressions for the individual limits. The reactions found to be necessary and apparently sufficient to account for the hydrogen/oxygen spontaneous ignition peninsula are those of chain destruction in triple collisions, destruction at the wall of three different chain carriers, first-order branching, second-order branching, the regeneration of ‘dead’ chains and a chain-initiating process.

scholarly journals 1H n.m.r. studies of insulin. Assignment of resonances and properties of tyrosine residues

1985 ◽  
Vol 229 (3) ◽  
pp. 731-737 ◽  
Author(s):  
J H Bradbury ◽  
V Ramesh
Keyword(s):  
Spin Echo ◽  
Double Resonance ◽  
Pulse Sequences ◽  
Crystallographic Data ◽  
Tyrosine Residue ◽  
Tyrosine Residues ◽  
Titration Curves ◽  
Echo Pulse

The assignment of the aromatic 1H n.m.r. resonances of the four tyrosine residues of bovine 2-zinc insulin is reported, based on double resonance techniques, use of Hahn spin echo pulse sequences and examination of specific derivatives nitrated at tyrosines A14 and A19 as well as des-(B26-B30)-insulin. Titration curves of the four tyrosine residues show that residues A14 and B16 have normal pK' values of 10.3-10.6 in solution, consistent with their accessibility to solvent in monomer and dimer in the crystal. Tyrosine residues A19 and B26 have pK' values of 11.4 and exhibit other features in their titration curves that are consistent with limited accessibility to solvent and a nonpolar environment. The meta protons of residues B16 and B26 both observe the titration of a nearby tyrosine residue, probably A19. Interpretation of the n.m.r. data obtained in solution is consistent with the crystallographic data for the monomer and dimer obtained on insulin crystals [Blundell, Dodson, Hodgkin & Mercola (1972) Adv. Protein Chem. 26, 279-402].

Religious Symbolism and Conscientious Objection in the Workplace: An Evaluation of Strasbourg's Judgment in Eweida and others v United Kingdom

2013 ◽  
Vol 15 (2) ◽  
pp. 191-203 ◽  
Author(s):  
Mark Hill
Keyword(s):  
United Kingdom ◽  
Same Sex ◽  
Same Sex Couples ◽  
Religious Symbolism ◽  
The United Kingdom ◽  
European Court ◽  
Domestic Courts ◽  
A Chain ◽  
The Individual ◽  
The Right

The judgment of the European Court of Human Rights in Eweida and others v United Kingdom1 related to two pairs of cases.2 The first pair concerned a British Airways check-in clerk and a nurse, each of whom complained that dress codes at their respective places of work prevented them from openly wearing a small cross on a chain around their neck. In the second pair, a registrar of marriages and a relationship counsellor refused to offer their respective services to same-sex couples on the basis that homosexual acts were incompatible with their religious beliefs. Having failed to obtain relief in the domestic courts, all four applicants took their claims to Strasbourg, which heard oral argument last September. Judgment was pronounced on 15 January 2013. This Comment considers the broad thrust of the judgment, particularly the threefold manner by which the Court has clarified and embedded the right to freedom of religion, the practical outcome in the individual cases, and the likely effect of the judgment upon future litigation in the domestic courts of the United Kingdom.

In Situ Coloration of Silk with Coupling Reaction and the Spectrum Characteristics

2013 ◽  
Vol 796 ◽  
pp. 428-431
Author(s):  
Wei Guo Chen ◽  
Zong Qian Wang ◽  
Zhi Hua Cui ◽  
Zhao Cheng Meng
Keyword(s):  
Silk Fibroin ◽  
Coupling Reaction ◽  
Coupling Reactions ◽  
Tyrosine Residue ◽  
Fastness Properties ◽  
Silk Industry ◽  
Tyrosine Residues ◽  
Spectrum Characteristics ◽  
Dyeing Method

High wet fastness dyeing is always the hot issue of silk industry. The plenty of tyrosine residue in silk protein may contribute an opportunity to solve this problem. In this paper, in situ coloration of silk is described using coupling reaction between diazonium compounds, made from different arylamine derivatives, and tyrosine residues in the silk fibroin. The spectra of coloured silk and the washing and rubbing fastness were measured. The results suggest that the use of coupling reactions could be developed into a dyeing method for silk. The wet fastness properties of such coloration are good because the chromophores are incorporated into the protein chains.

scholarly journals Bis(μ-benzoato-κ2O:O′)bis(benzoato-κO)octabutyldi-μ3-oxido-tetratin(IV)

2017 ◽  
Vol 73 (3) ◽  
pp. 322-326
Author(s):  
Hans Reuter ◽  
Coco K. Y. A. Okio
Keyword(s):  
Phenyl Group ◽  
Asymmetric Unit ◽  
Ladder Structure ◽  
Mean Values ◽  
Distorted Octahedral Coordination ◽  
First Approximation ◽  
Carboxylate Groups ◽  
Distorted Octahedral ◽  
A Chain ◽  
The Individual

The asymmetric unit of the title compound, [{Sn(C4H9)2(C6H5COO)}2O]2, consists of two half molecules, completed by application of inversion symmetry. Both molecules adopt a ladder structure typical for this class of dimeric tetraorganodistannoxane dicarboxylates characterized by a centrosymmetric four-membered (Sn—O)2ring of rhomboidal shape that is extended on both sides by folded six-membered Sn—O—C rings. To a first approximation, both kinds of Sn atoms (Sniand Sno) are trigonal–bipyramidally coordinated. The bond angles between then-butyl groups are widened [135.64 (7)–146.20 (7)°] in comparison with an ideal trigonal bipyramid. Sn—O bond lengths within the {R2SnO3} coordination sphere depend strongly on the position of the corresponding O atom – axial (ax) or equatorial (eq) – as well as on the functionality of the carboxylate groups which exhibit μ2(–COOi) and μ1(–COOo) coordination modes, respectively. In summary, the following sequence of distances [mean values] is found:d(Sno—Oμ3)eq[2.024 (2) Å] <d(Sni—Oμ3)eq[2.044 (2) Å] <d(Sni—Oμ3)ax[2.158 (6) Å] <d(Sno—Oμ1-carb)ax[2.182 (6) Å] <d(Sni—Oμ2-carb)ax[2.250 (2) Å] ≃d(Sno—Oμ2-carb)ax[2.247 (12) Å]. Then-butyl groups adopt ananti–anticonformation with exception of two disordered outern-butyl groups of the second molecule which exhibitgauche–antiandanti–gaucheconformations. Weak intramolecular Sn...O interactions between the different O atoms of the outer carboxyl groups with the inner, as well as outer, Sn atoms give rise to a strongly distorted octahedral coordination at these Sn atoms. Intermolecular interactions between the individual molecules are restricted to van der Waals and O...H—C interactions of which a nearly linear very short C—H...O contact between the H atom of the phenyl group of one of the molecules with the outer non-coordinating C=O group of the other molecule is the most prominent. It gives rise to a chain-like arrangement of the molecules along [111]. The twon-butyl groups attached to the outer Sn atom of one molecule are disordered over two sets of sites with occupancies of 0.806 (3)/0.194 (3) and 0.702 (3)/0.298 (3).

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