Effect of viscogens on the kinetic response of a photoperturbed allosteric protein.
J Chem Phys
; 141(22): 22D514, 2014 Dec 14.
Article
em En
| MEDLINE
| ID: mdl-25494785
ABSTRACT
By covalently binding a photoswitchable linker across the binding groove of the PDZ2 domain, a small conformational change can be photo-initiated that mimics the allosteric transition of the protein. The response of its binding groove is investigated with the help of ultrafast pump-probe IR spectroscopy from picoseconds to tens of microseconds. The temperature dependence of that response is compatible with diffusive dynamics on a rugged energy landscape without any prominent energy barrier. Furthermore, the dependence of the kinetics on the concentration of certain viscogens, sucrose, and glycerol, has been investigated. A pronounced viscosity dependence is observed that can be best fit by a power law, i.e., a fractional viscosity dependence. The change of kinetics when comparing sucrose with glycerol as viscogen, however, provides strong evidence that direct interactions of the viscogen molecule with the protein do play a role as well. This conclusion is supported by accompanying molecular dynamics simulations.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Domínios PDZ
/
Simulação de Dinâmica Molecular
Limite:
Humans
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
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