TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

Each of the two polypeptide chains of molecular weight 17, 000 forming a regulatory subunit of the E. coli ATCase(aspartate transcarbamylase). The ATCase of E. coli can be dissociated with mercurial agents to yield two identical catalytic subunits and three identical regulatory subunits.  2, record 1, English, - R%20chain

Record number: 1, Textual support number: 1 OBS

One atom of Zn⁺² is bound to each of the R chains and each of the R chains can bind one molecule of the modulator CTP.  1, record 1, English, - R%20chain

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

Chacune des deux chaînes polypeptidiques (P.M. 17 000) composant une sous-unité régulatrice de l'aspartate transcarbamylase d'E. coli (ATCase). L'ATCase d'E. coli comprend trois sous-unités régulatrices et deux sous-unités catalytiques.  2, record 1, French, - cha%C3%AEne%20R

Record number: 1, Textual support number: 1 CONT

L'aspartate-carbamyl-transférase a un poids moléculaire de 300 000. On le dissocie aisément en cinq sous-unités : - deux sous-unités catalytiques, [...] - trois sous-unités régulatrices, de poids moléculaire 34 000, et constituées chacune de deux chaînes polypeptidiques (chaînes R), liées d'ailleurs à un atome de Zinc (Zn²⁺ : chacune de ces sous-unités régulatrices possède deux sites de fixation du modulateur CTP, un sur chaque chaîne R. L'activité de ces trois sous-unités est strictement régulatrice : elles n'ont aucun pouvoir catalytique.  3, record 1, French, - cha%C3%AEne%20R

Record 1,  Textual support,  Spanish

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 DEF

The enzyme(EC 2. 6. 1. 1) that catalyzes the reaction of aspartate with 2-oxoglutarate to give glutamate and oxaloacetate. It contains pyridoxal phosphate. Its concentration in blood may be raised in liver and heart diseases that are associated with damage to those tissues.  6, record 2, English, - aspartate%20aminotransferase

Record number: 2, Textual support number: 1 OBS

An enzyme normally present in many tissues and body fluids; high concentrations are associated with damage to cells, especially of the heart and liver.  5, record 2, English, - aspartate%20aminotransferase

Record 2,  Textual support,  French

Record number: 2, Textual support number: 1 CONT

L'une des deux transaminases qui ont été étudiées en clinique dans le sérum sanguin. Elle catalyse la réaction entre l'acide glutamique et l'acide oxalo-acétique d'une part, et l'acide aspartique et l'acide alpha-cétoglutarique d'autre part.  2, record 2, French, - s%C3%A9rum%20glutamo%2Doxalac%C3%A9tique%20transaminase

Record 2,  Textual support,  Spanish

Record 3,  Textual support,  English

Record number: 3, Textual support number: 1 DEF

The subunit of a regulatory enzyme that has no enzymatic activity but binds the effector.  1, record 3, English, - regulatory%20subunit

Record number: 3, Textual support number: 1 CONT

The aspartate transcarbamoylase of E. coli... can be dissociated... to yield two identical catalytic subunits and three identical regulatory subunits.... The mixture retains catalytic activity but the reaction is not inhibited by CTP so long as the catalytic and regulatory subunits are detached from each other.  2, record 3, English, - regulatory%20subunit

Record number: 3, Textual support number: 1 OBS

See "catalytic subunit".  1, record 3, English, - regulatory%20subunit

Record 3,  Textual support,  French

Record number: 3, Textual support number: 1 DEF

Sous-unité d'un enzyme allostérique capable de fixer l'effecteur allostérique (mais dépourvue d'activité catalytique).  2, record 3, French, - sous%2Dunit%C3%A9%20r%C3%A9gulatrice

Record number: 3, Textual support number: 1 CONT

La principale action du cAMP dans le métabolisme est de stimuler l'activité des protéines kinases, un groupe d'enzymes qui catalyse la phosphorylation des protéines. [...] L'enzyme possède deux sous-unités : l'une catalytique et l'autre, régulatrice et qui peut lier le cAMP. En absence de cAMP, les sous-unités régulatrice et catalytique forment un complexe enzymatiquement inactif. La liaison du cAMP à la sous-unité régulatrice entraîne un changement conformationnel et dissocie le complexe. La sous-unité catalytique ainsi libérée est enzymatiquement active et elle phosphoryle les autres enzymes.  3, record 3, French, - sous%2Dunit%C3%A9%20r%C3%A9gulatrice

Record 3,  Textual support,  Spanish

Record 4,  Textual support,  English

Record number: 4, Textual support number: 1 CONT

The ATCase of E. coli... has a molecular weight of about 310, 000 but can be dissociated by treatment with mercurial reagents to yield two identical catalytic subunits and three identical regulatory subunits. Each of the two catalytic subunits has a molecular weight of about 100, 000 and contains three polypeptide chains of molecular weight 34, 000 called C chains. Each catalytic subunit contains three binding sites for the substrate aspartate, one on each of the three C chains. The catalytic subunits have enzymatic activity but are not sensitive to the modulator CTP.  2, record 4, English, - C%20chain

Record 4,  Textual support,  French

Record number: 4, Textual support number: 1 DEF

Chacune des trois chaînes polypeptidiques (P.M. 34 000) composant une sous-unité catalytique de l'aspartate transcarbamylase d'E. coli (ATCase). L'ATCase d'E. coli comprend deux sous-unités catalytiques et trois sous-unités régulatrices.  2, record 4, French, - cha%C3%AEne%20C

Record number: 4, Textual support number: 1 CONT

Chacune des 2 sous-unités catalytiques [...] de l'ATCase [...] possède trois sites de fixation pour le substrat, l'aspartate, un site sur chacune des chaînes C. Ces sous-unités catalytiques ont une activité enzymatique mais ne sont pas sensibles au modulateur CTP.  3, record 4, French, - cha%C3%AEne%20C

Record number: 4, Textual support number: 1 OBS

Voir «sous-unité catalytique».  2, record 4, French, - cha%C3%AEne%20C

Record 4,  Textual support,  Spanish

Record 5,  Textual support,  English

Record number: 5, Textual support number: 1 DEF

Promotion of a chemical reaction by addition of a substance or enzyme(catalyst) that partakes in, but is not permanently affected by the reaction. In the case of enzymes, it is mediated by the functional groups found in amino acid side chains and coenzymes. Notably, the amino acid side chains of histidine, serine, cysteine, lysine, glutamate, and aspartate are frequently directly involved in the catalytic process. Coenzymes or metals work in conjunction with enzymes to provide a greater variety of functional groups than is available through amino acid side chains alone.  2, record 5, English, - catalysis

Record number: 5, Textual support number: 1 CONT

DNA technology enables the facile modification of proteins by highly specific mutagenesis of their genes. Enzymes with novel properties may be produced in large quantities from the mutant genes. Kinetic analysis of the mutant enzymes can be combined with high-resolution structural data from protein X-ray crystallography to provide direct measurements on the relationships between structure and function. In particular, the strength and nature of enzyme-substrate interactions and their roles in catalysis and specificity may be studied.  3, record 5, English, - catalysis

Record 5,  Textual support,  French

Record number: 5, Textual support number: 1 DEF

Accélération d'une réaction chimique grâce à la présence, en petite quantité, d'une substance (appelée catalyseur), qui est retrouvée inchangée à la fin de la réaction.  2, record 5, French, - catalyse

Record number: 5, Textual support number: 1 CONT

Certains enzymes subissent une activation irréversible quand ils sont traités par des agents capables de se fixer de façon covalente à un groupement fonctionnel indispensable à la catalyse, ce qui conduit à la formation d'une molécule enzymatique inactive.  3, record 5, French, - catalyse

Record 5,  Textual support,  Spanish

Record number: 5, Textual support number: 1 DEF

Proceso por el cual varía la velocidad de una reacción química por la presencia de una sustancia, el catalizador, que al finalizar la reacción permanece inalterada.  1, record 5, Spanish, - cat%C3%A1lisis

Record 6,  Textual support,  English

Record number: 6, Textual support number: 1 DEF

Distinct polypeptide chain in which lies the domain accommodating the catalytic site of complex enzymes. It is completely separated from the domain building up the binding site for the regulatory effector(s). From an evolutionary viewpoint, it is probable that gene fusion did occur in most cases rather than that originally continuous polypeptide chains have separated. In some oligomeric enzymes the allosteric site may have appeared as a result of gene duplication, e.g. in glutamate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase, whereas in others by acquisition of a foreign structural gene, e.g. the NAD-binding domain in glycogen phosphorylase. However, in present day complex enzymes the catalytic and regulatory protein units remained separate, but associable, entities.  2, record 6, English, - catalytic%20subunit

Record number: 6, Textual support number: 1 CONT

The ATCase of E. coli has... a molecular weight of about 310, 000 but can be dissociated by treatment with mercurial reagents to yield two identical catalytic subunits and three identical regulatory subunits. Each of the two catalytic subunits has a molecular weight of about 100, 000 and contains three polypeptide chains of molecular weight 34, 000 called C chains. Each catalytic subunit contains three binding sites for the substrate aspartate, one on each of the three C chains. The catalytic subunits have enzymatic activity but are not sensitive to the modulator CTP.  3, record 6, English, - catalytic%20subunit

Record 6,  Textual support,  French

Record number: 6, Textual support number: 1 CONT

Lorsque la molécule native d'ATCase est dissociée en un mélange de ses sous-unités catalytiques et régulatrices, ce mélange fait toujours montre d'activité catalytique, mais la réaction n'est pas inhibée par le CTP tant que les sous-unités catalytiques et régulatrices sont séparées les unes des autres. Pour que l'inhibition par le CTP puisse avoir lieu, il faut que les sous-unités catalytiques et régulatrices soient physiquement associées dans la molécule oligomérique d'ATCase intacte.  1, record 6, French, - sous%2Dunit%C3%A9%20catalytique

Record 6,  Textual support,  Spanish

Record 7,  Textual support,  English

Record number: 7, Textual support number: 1 CONT

A critical reaction in all organisms is the transfer of an amino group from one carbon skeleton to another by the process of transamination. Frequently, the most active exchange is between glutamate and aspartate.... This reaction is catalyzed by aspartate aminotransferase(also known as glutamate-oxaloacetate transaminase, glutamate-aspartate transaminase, and similar permutations).  2, record 7, English, - transamination

Record 7,  Textual support,  French

Record number: 7, Textual support number: 1 CONT

On connaît maintenant la quasi-totalité des amino-transférases (transaminases) capables d'assurer la transamination de tous les amino-acides (E.C. 2.6.1....). Toutes ces transaminases fonctionnent avec un coenzyme commun, le phosphate de pyridoxal, selon un mécanisme moléculaire bien connu. Dans les cellules encaryotes, ces enzymes sont localisés à la fois dans le cytosol et dans les mitochondries : il en existe ainsi plusieurs variétés moléculaires séparables par électrofocalisation.  2, record 7, French, - transamination

Record 7,  Textual support,  Spanish

Record 8,  Textual support,  English

Record number: 8, Textual support number: 1 CONT

Enhanced well productivity potential from a new high-density reservoir drilling fluid. ... The new fluid system ... derives its viscosity solely from an interaction between a specially modified starch (DFS) and an inorganic magnesium compound (HRMgO) [= highly reactive magnesium oxide].  3, record 8, English, - inorganic%20magnesium%20compound

Record number: 8, Textual support number: 2 CONT

Dietary Mg [magnesium] supplementation using inorganic Mg sources such as MgSO₄ and MgCl₂ have... been shown to improve meat quality. Studies comparing the influence of organic and inorganic magnesium compounds on meat quality indicate that the improvements in muscle colour, drip loss, and the reductions in the incidence of PSE [pale, soft and exudative pork] were greater with organic magnesium compounds such as magnesium aspartate and magnesium Bioplex.  4, record 8, English, - inorganic%20magnesium%20compound

Record 8,  Textual support,  French

Record 8,  Textual support,  Spanish

Record 9,  Textual support,  English

Record number: 9, Textual support number: 1 CONT

... and are the world's most important textile fiber. Purified wood cellulose(from... serine, cystine(cysteine), aspartic acid(aspartate), asparagine...  1, record 9, English, - asparagine

Record 9,  Textual support,  French

Record 9,  Textual support,  Spanish

Record 10,  Textual support,  English

Record number: 10, Textual support number: 1 CONT

Lysine has two distinct biosynthetic pathways, the diaminopimelic acid pathway and the [alpha]-aminoadipic acid pathway. The diaminopimelic acid pathway operates in bacteria, some lower fungi, algae, and higher plants. It begins with condensation of pyruvate with aspartate ß-semialdehyde and ends with decarboxylation of diaminopimelate. Diaminopimelate is an important constituent of bacterial cell walls. The [alpha]-aminoadipic acid pathway is less widespread and functions in other lower fungi, in higher fungi, and in the protist Euglena.  2, record 10, English, - diaminopimelate

Record 10,  Textual support,  French

Record number: 10, Textual support number: 1 DEF

Sel de l'acide diaminopimélique.  2, record 10, French, - diaminopim%C3%A9late

Record number: 10, Textual support number: 1 CONT

Méthode précise de dosage du diaminopimélate, étude de sa présence chez les animaux axéniques et embryons de poulet.  3, record 10, French, - diaminopim%C3%A9late

Record 10,  Textual support,  Spanish

Record 11,  Textual support,  English

Record number: 11, Textual support number: 1 DEF

A compound that serves as a component of cell wall mucopeptide in some bacteria and as a source of lysine in all bacteria.  3, record 11, English, - diaminopimelic%20acid

Record number: 11, Textual support number: 1 CONT

Design and synthesis of inhibitors of biosynthesis of peptidoglycan, a key constituent of bacterial cell walls and a target for broad spectrum antibiotics. Special emphasis is on blocking formation and utilization of diaminopimelic acid (DAP) as well as preventing polymerization of the polysaccharide backbone.  2, record 11, English, - diaminopimelic%20acid

Record number: 11, Textual support number: 2 CONT

Lysine has two distinct biosynthetic pathways, the diaminopimelic acid pathway and the [alpha]-aminoadipic acid pathway. The diaminopimelic acid pathway operates in bacteria, some lower fungi, algae, and higher plants. It begins with condensation of pyruvate with aspartate ß-semialdehyde and ends with decarboxylation of diaminopimelate. Diaminopimelate is an important constituent of bacterial cell walls. The [alpha]-aminoadipic acid pathway is less widespread and functions in other lower fungi, in higher fungi, and in the protist Euglena.  4, record 11, English, - diaminopimelic%20acid

Record number: 11, Textual support number: 1 OBS

DAP: This might be an in-house or a non-recognized abbreviation; not to be used alone, to avoid any risk of confusion.  5, record 11, English, - diaminopimelic%20acid

Record 11,  Textual support,  French

Record number: 11, Textual support number: 1 CONT

diaminopimélate : Sel de l'acide diaminopimélique.  4, record 11, French, - acide%20diaminopim%C3%A9lique

Record number: 11, Textual support number: 2 CONT

On utilise pour obtenir un «confinement biologique», des souches d'E. coli réceptrices d'ADN étranger qui sont exigeantes en acide diaminopimélique (DAP), substance uniquement d'origine bactérienne et peu répandue dans l'environnement. On a pu montrer à l'aide de modèles gnotoxéniques que les parois de certaines bactéries de la flore du tube digestif pouvaient servir de source de DAP aux mutants exigeants et permettre leur croissance «in vivo».  2, record 11, French, - acide%20diaminopim%C3%A9lique

Record number: 11, Textual support number: 1 OBS

DAP : abréviation non officielle; ne pas l'utiliser seule, pour éviter tout risque de confusion.  5, record 11, French, - acide%20diaminopim%C3%A9lique

Record 11,  Textual support,  Spanish

Record 12,  Textual support,  English

Record number: 12, Textual support number: 1 CONT

Aspartate kinase(AK) catalyzes the first reaction of common biosynthetic pathway of threonine, lysine and methionine in plants and bacteria.  2, record 12, English, - aspartate%20kinase

Record 12,  Textual support,  French

Record number: 12, Textual support number: 1 OBS

L'aspartate kinase (AK) catalyse la première étape de la biosynthèse commune à la thréonine, à la lysine et à la méthionine chez les plantes et les bactéries.  3, record 12, French, - aspartate%20kinase

Record 12,  Textual support,  Spanish

Record 13,  Textual support,  English

Record number: 13, Textual support number: 1 CONT

reaction mechanism of aspartate transcarbamylase dissociated from carbamylphosphate synthetase by genetic alteration.  1, record 13, English, - genetic%20alteration

Record 13,  Textual support,  French

Record number: 13, Textual support number: 1 CONT

l'établissement d'une hydrogénase exprimée en permanence chez les procaryotes photosynthétisants par altération génétique et inhibition métabolique.  1, record 13, French, - alt%C3%A9ration%20g%C3%A9n%C3%A9tique

Record number: 13, Textual support number: 1 OBS

Les ouvrages suivants ont été utilisés mais ne possèdent pas de codes de source : Archives of Biochemistry, Commission of the European Communities et Biologisches Zentralblatt.  1, record 13, French, - alt%C3%A9ration%20g%C3%A9n%C3%A9tique

Record 13,  Textual support,  Spanish

Record 14,  Textual support,  English

Record number: 14, Textual support number: 1 CONT

in feedback inhibition the end-product of a metabolic pathway acts as an allosteric inhibitor of the first enzyme of this metabolic chain. Thus, when enough product is synthesized, the entire chain can be shut off, and useless accumulation of metabolites is avoided. An example is provided by aspartate transcarbamylase, the first enzyme in pyrimidine biosynthesis, which is inhibited by CTP, the end-product of this biosynthetic pathway.  1, record 14, English, - transcarbamylase

Record 14,  Textual support,  French

Record number: 14, Textual support number: 1 CONT

dans la rétroinhibition, le produit terminal d'une voie métabolique agit comme un inhibiteur allostérique de la première enzyme de cette chaîne métabolique. Ainsi, quand la quantité du produit synthétisé est suffisante, la chaîne entière peut être arrêtée et l'accumulation inutile de métabolites est évitée. Un exemple de cette forme de contrôle nous est fourni par l'aspartate transcarbamylase, la première enzyme dans la biosynthèse des pyrimidines.  1, record 14, French, - transcarbamylase

Record 14,  Textual support,  Spanish

Record 15,  Textual support,  English

Record number: 15, Textual support number: 1 CONT

The transfer of the second amino group to citrulline occurs by a condensation reaction between the amino group of aspartate and the carbonyl carbon of citrulline in the presence of ATP to form argininosuccinate... This reaction is catalyzed by arginosuccinate synthetase of the liver cytosol...  1, record 15, English, - argininosuccinate%20synthetase

Record 15,  Textual support,  French

Record number: 15, Textual support number: 1 OBS

Enzyme du cycle de synthèse de l'urée.  2, record 15, French, - argininosuccinate%20synth%C3%A9tase

Record 15,  Textual support,  Spanish

Record 16,  Textual support,  English

Record number: 16, Textual support number: 1 CONT

The area cycle has several complex steps... the transfer of the second amino group to citrulline occurs by a condensation reaction between the amino group of aspartate and the carbonyl carbon of citrulline in the presence of ATP to form argininosuccinate. This reaction is catalyzed by argininosuccinate synthetase of the liver cytosol, a Mg²+-dependent enzyme.... In the next step argininosuccinate is reversibly cleaved by argininosuccinate lyase to form free arginine and fumarate.  1, record 16, English, - argininosuccinate%20lyase

Record 16,  Textual support,  French

Record number: 16, Textual support number: 1 OBS

Enzyme du cycle de synthèse de l'urie.  2, record 16, French, - argininosuccinate%20lyase

Record 16,  Textual support,  Spanish

Record 17,  Textual support,  English

Record number: 17, Textual support number: 1 CONT

[A few] mutants could be selected because they are resistant to a compound called AEC, which resembles lysine so closely that it mimics its regulatory effect, inhibiting aspartate kinase even if no lysine is being synthesized. In the presence of AEC, wild strains die as a result of lysine starvation, whereas the mutants proliferate and form colonies.  1, record 17, English, - AEC

Record 17,  Textual support,  French

Record number: 17, Textual support number: 1 CONT

[Certains] mutants ont pu être isolés parce qu'ils sont résistants à un composé appelé AEC, lequel ressemble tellement à la lysine qu'il reproduit son action régulatrice en inhibant l'aspartate kinase, même en l'absence de lysine : aussi, en présence d'AEC, les souches sauvages meurent par privation de lysine, alors que les mutants prolifèrent et forment des colonies.  1, record 17, French, - AEC

Record 17,  Textual support,  Spanish