Subunit coupling and kinetic co-operativity of polymeric enzymes. Amplification, attenuation and inversion effects
Identifieur interne : 003836 ( Main/Exploration ); précédent : 003835; suivant : 003837Subunit coupling and kinetic co-operativity of polymeric enzymes. Amplification, attenuation and inversion effects
Auteurs : Jacques Ricard [France] ; Georges Noat [France]Source :
- Journal of Theoretical Biology [ 0022-5193 ] ; 1985.
Abstract
The principles of structural kinetics, as applied to dimeric enzymes, allow us to understand how the strength of subunit coupling controls both substrate-binding co-operativity, under equilibrium conditions, and kinetic co-operativity, under steady state conditions. When subunits are loosely coupled, positive substrate-binding co-operativity may result in either an inhibition by excess substrate or a positive kinetic co-operativity. Alternatively, negative substrate-binding co-operativity is of necessity accompanied by negative kinetic co-operativity. Whereas the extent of negative kinetic co-operativity is attenuated with respect to the corresponding substrate-binding co-operativity, the positive kinetic co-operativity is amplified with respect to that of the substrate-binding co-operativity. Strong kinetic co-operativity cannot be generated by a loose coupling of subunits. If subunits are tightly coupled, that is if the conformational change of a subunit is propagated to the other, the dimeric enzyme may display apparently surprising co-operativity effects. If the strain of the active sites generated by subunit coupling is relieved in the non-liganded and fully-liganded states, both substrate-binding co-operativity and kinetic co-operativity cannot be negative. If the strain of the active sites however, is not relieved in these states, negative substrate-binding co-operativity is accompanied by either a positive or a negative co-operativity. The possible occurrence of a reversal of kinetic co-operativity, with respect to substrate-binding co-operativity, is the direct consequence of quaternary constraints in the dimeric enzyme. Moreover, tight coupling between subunits may generate a positive kinetic co-operativity which is not associated with any substrate-binding co-operativity. In other words a dimeric enzyme may well bind the substrate in a non co-operative fashion and display a positive kinetic co-operativity generated by the strain of the active sites.
Url:
DOI: 10.1016/S0022-5193(85)80244-7
Affiliations:
Links toward previous steps (curation, corpus...)
- to stream Istex, to step Corpus: 000842
- to stream Istex, to step Curation: 000842
- to stream Istex, to step Checkpoint: 001559
- to stream Main, to step Merge: 003994
- to stream Main, to step Curation: 003836
Le document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">Subunit coupling and kinetic co-operativity of polymeric enzymes. Amplification, attenuation and inversion effects</title>
<author><name sortKey="Ricard, Jacques" sort="Ricard, Jacques" uniqKey="Ricard J" first="Jacques" last="Ricard">Jacques Ricard</name>
</author>
<author><name sortKey="Noat, Georges" sort="Noat, Georges" uniqKey="Noat G" first="Georges" last="Noat">Georges Noat</name>
</author>
</titleStmt>
<publicationStmt><idno type="wicri:source">ISTEX</idno>
<idno type="RBID">ISTEX:DC94BD5D45C48482853432860E10FF9DC2F2A286</idno>
<date when="1985" year="1985">1985</date>
<idno type="doi">10.1016/S0022-5193(85)80244-7</idno>
<idno type="url">https://api.istex.fr/document/DC94BD5D45C48482853432860E10FF9DC2F2A286/fulltext/pdf</idno>
<idno type="wicri:Area/Istex/Corpus">000842</idno>
<idno type="wicri:Area/Istex/Curation">000842</idno>
<idno type="wicri:Area/Istex/Checkpoint">001559</idno>
<idno type="wicri:doubleKey">0022-5193:1985:Ricard J:subunit:coupling:and</idno>
<idno type="wicri:Area/Main/Merge">003994</idno>
<idno type="wicri:Area/Main/Curation">003836</idno>
<idno type="wicri:Area/Main/Exploration">003836</idno>
</publicationStmt>
<sourceDesc><biblStruct><analytic><title level="a" type="main" xml:lang="en">Subunit coupling and kinetic co-operativity of polymeric enzymes. Amplification, attenuation and inversion effects</title>
<author><name sortKey="Ricard, Jacques" sort="Ricard, Jacques" uniqKey="Ricard J" first="Jacques" last="Ricard">Jacques Ricard</name>
<affiliation wicri:level="3"><country xml:lang="fr">France</country>
<wicri:regionArea>Centre de Biochimie et de Biologie Moléculaire du CNRS, BP 71, 13402 Marseille Cedex 9</wicri:regionArea>
<placeName><region type="region" nuts="2">Provence-Alpes-Côte d'Azur</region>
<settlement type="city">Marseille</settlement>
</placeName>
</affiliation>
</author>
<author><name sortKey="Noat, Georges" sort="Noat, Georges" uniqKey="Noat G" first="Georges" last="Noat">Georges Noat</name>
<affiliation wicri:level="3"><country xml:lang="fr">France</country>
<wicri:regionArea>Centre de Biochimie et de Biologie Moléculaire du CNRS, BP 71, 13402 Marseille Cedex 9</wicri:regionArea>
<placeName><region type="region" nuts="2">Provence-Alpes-Côte d'Azur</region>
<settlement type="city">Marseille</settlement>
</placeName>
</affiliation>
</author>
</analytic>
<monogr></monogr>
<series><title level="j">Journal of Theoretical Biology</title>
<title level="j" type="abbrev">YJTBI</title>
<idno type="ISSN">0022-5193</idno>
<imprint><publisher>ELSEVIER</publisher>
<date type="published" when="1985">1985</date>
<biblScope unit="volume">117</biblScope>
<biblScope unit="issue">4</biblScope>
<biblScope unit="page" from="633">633</biblScope>
<biblScope unit="page" to="649">649</biblScope>
</imprint>
<idno type="ISSN">0022-5193</idno>
</series>
<idno type="istex">DC94BD5D45C48482853432860E10FF9DC2F2A286</idno>
<idno type="DOI">10.1016/S0022-5193(85)80244-7</idno>
<idno type="PII">S0022-5193(85)80244-7</idno>
<idno type="ArticleID">85802447</idno>
</biblStruct>
</sourceDesc>
<seriesStmt><idno type="ISSN">0022-5193</idno>
</seriesStmt>
</fileDesc>
<profileDesc><textClass></textClass>
<langUsage><language ident="en">en</language>
</langUsage>
</profileDesc>
</teiHeader>
<front><div type="abstract" xml:lang="en">The principles of structural kinetics, as applied to dimeric enzymes, allow us to understand how the strength of subunit coupling controls both substrate-binding co-operativity, under equilibrium conditions, and kinetic co-operativity, under steady state conditions. When subunits are loosely coupled, positive substrate-binding co-operativity may result in either an inhibition by excess substrate or a positive kinetic co-operativity. Alternatively, negative substrate-binding co-operativity is of necessity accompanied by negative kinetic co-operativity. Whereas the extent of negative kinetic co-operativity is attenuated with respect to the corresponding substrate-binding co-operativity, the positive kinetic co-operativity is amplified with respect to that of the substrate-binding co-operativity. Strong kinetic co-operativity cannot be generated by a loose coupling of subunits. If subunits are tightly coupled, that is if the conformational change of a subunit is propagated to the other, the dimeric enzyme may display apparently surprising co-operativity effects. If the strain of the active sites generated by subunit coupling is relieved in the non-liganded and fully-liganded states, both substrate-binding co-operativity and kinetic co-operativity cannot be negative. If the strain of the active sites however, is not relieved in these states, negative substrate-binding co-operativity is accompanied by either a positive or a negative co-operativity. The possible occurrence of a reversal of kinetic co-operativity, with respect to substrate-binding co-operativity, is the direct consequence of quaternary constraints in the dimeric enzyme. Moreover, tight coupling between subunits may generate a positive kinetic co-operativity which is not associated with any substrate-binding co-operativity. In other words a dimeric enzyme may well bind the substrate in a non co-operative fashion and display a positive kinetic co-operativity generated by the strain of the active sites.</div>
</front>
</TEI>
<affiliations><list><country><li>France</li>
</country>
<region><li>Provence-Alpes-Côte d'Azur</li>
</region>
<settlement><li>Marseille</li>
</settlement>
</list>
<tree><country name="France"><region name="Provence-Alpes-Côte d'Azur"><name sortKey="Ricard, Jacques" sort="Ricard, Jacques" uniqKey="Ricard J" first="Jacques" last="Ricard">Jacques Ricard</name>
</region>
<name sortKey="Noat, Georges" sort="Noat, Georges" uniqKey="Noat G" first="Georges" last="Noat">Georges Noat</name>
</country>
</tree>
</affiliations>
</record>
Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Musique/explor/OperaV1/Data/Main/Exploration
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 003836 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd -nk 003836 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien |wiki= Wicri/Musique |area= OperaV1 |flux= Main |étape= Exploration |type= RBID |clé= ISTEX:DC94BD5D45C48482853432860E10FF9DC2F2A286 |texte= Subunit coupling and kinetic co-operativity of polymeric enzymes. Amplification, attenuation and inversion effects }}
This area was generated with Dilib version V0.6.21. |