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Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

Model for regulatory enzymes -- proposed by Koshland, Nemethy and Filmer -- according to which the enzyme undergoes a series of conformational changes as the various ligands become bound to the enzyme. Different types of site interactions may occur of which symmetry preservation, as in the symmetry model, may be a special case. In general, however, the symmetry of the enzyme molecule is not conserved, since a subunit changes its conformation as a ligand becomes bound to it. The capacity of the enzyme to bind substrate, positive effectors, and negative effectors is altered by the conformational changes which the subunits undergo.  1, record 1, English, - sequential%20model

Record number: 1, Textual support number: 1 CONT

Two types of models have been proposed for the cooperative interactions of the subunits of hemoglobin, the sequential model proposed by D. E. Koshland and the symmetry model of J. Monod and his colleagues. These models are also applicable to allosteric enzymes having multiple subunits, which are assumed to occur in two different conformations.  2, record 1, English, - sequential%20model

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 CONT

Les interprétations moléculaires du mécanisme des modulations allostériques ont été très marquées par les travaux concernant les coopérativités dans la molécule d'hémoglobine. De nombreux modèles ont été proposés. Les deux plus importants sont le modèle séquentiel de Koshland et Atkinson, et le modèle concerté de Monod, Wyman et Changeux. (...) Leur point commun est de considérer que toute sous-unité catalytique fixant le modulateur (première molécule de substrat par exemple) subit une déformation (...) qui se transmet aux autres sous-unités, et modifie ainsi leur affinité pour le substrat : c'est l'expression même de la coopérativité.  1, record 1, French, - mod%C3%A8le%20s%C3%A9quentiel

Record 1,  Textual support,  Spanish