Thrombin allosteric modulation revisited: a molecular dynamics study.
Research article published in Journal of molecular modeling (2009)
Abstract
The regulatory properties of thrombin are derived predominantly from its capacity to produce different functional conformations. Functional studies have revealed that two antagonistic thrombin conformations exist in equilibrium: the fast (procoagulant) and slow (anticoagulant) forms. The mechanisms whereby thrombin activity is regulated by the binding of different effectors remain among the most enigmatic and controversial subjects in the field of protein function. In order to obtain more detailed information on the dynamic events originating from the interaction with the Na(+) effector and ligand binding at the active site and anion binding exosite 1 (ABE1), we carried out molecular dynamics simulations of thrombin in different bound states. The results indicated that Na(+) release results in a more closed conformation of thrombin, which can be compared to the slow form. The conformational changes induced by displacement of the sodium ion from the Na-binding site include: (1) distortion of the 220- and 186-loops that constitute the Na-binding site; (2) folding back of the Trp148 loop towards the body of the protein, (3) a 180 degrees rotation of the Asp189 side-chain, and (4) projection of the Trp60D loop toward the solvent accompanied by the rearrangement of the Trp215 side chain toward the 95-100 loop. Our findings correlate well with the known structural and recognition properties of the slow and fast forms of thrombin, and are in accordance with the hypothesis that there is communication between the diverse functional domains of thrombin. The theoretical models generated from our MD simulations complement and advance the structural information currently available, leading to a more detailed understanding of thrombin structure and function.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
The regulatory properties of thrombin are derived predominantly from its capacity to produce different functional conformations. Functional studies have revealed that two antagonistic thrombin conformations exist in equilibrium: the fast (procoagulant) and slow (anticoagulant) forms.
Por qué esto importa para la hirudoterapia
Este estudio empleó simulaciones de dinámica molecular para explorar la regulación alostérica de la trombina, concretamente los cambios conformacionales desencadenados por la liberación del ion sodio y la unión de ligandos en el sitio activo y el exositio 1 de unión aniónica (ABE1). Los hallazgos mapean los cambios estructurales dinámicos entre las formas 'rápida' procoagulante y 'lenta' anticoagulante de la trombina. Este trabajo computacional es relevante para el dominio de ASH porque el ABE1 y el sitio activo son dianas primordiales de los anticoagulantes derivados de la sanguijuela, como la hirudina. Los modelos detallados de los dominios funcionales y las vías de comunicación de la trombina ayudan a elucidar el entorno molecular en el que ejercen sus efectos terapéuticos las secreciones de la sanguijuela. La limitación es que se trata de un estudio puramente teórico y computacional, sin sanguijuelas, ensayos biológicos ni datos clínicos; su conexión con la hirudoterapia es enteramente indirecta y mecanística.
Citación
Thrombin allosteric modulation revisited: a molecular dynamics study.
de Amorim et al. · Journal of molecular modeling, 2009
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: June 18, 2026