Protein self-diffusion in crowded solutions.
Proc Natl Acad Sci U S A
; 108(29): 11815-20, 2011 Jul 19.
Article
em En
| MEDLINE
| ID: mdl-21730176
ABSTRACT
Macromolecular crowding in biological media is an essential factor for cellular function. The interplay of intermolecular interactions at multiple time and length scales governs a fine-tuned system of reaction and transport processes, including particularly protein diffusion as a limiting or driving factor. Using quasielastic neutron backscattering, we probe the protein self-diffusion in crowded aqueous solutions of bovine serum albumin on nanosecond time and nanometer length scales employing the same protein as crowding agent. The measured diffusion coefficient D(Ï) strongly decreases with increasing protein volume fraction Ï explored within 7% ≤ Ï ≤ 30%. With an ellipsoidal protein model and an analytical framework involving colloid diffusion theory, we separate the rotational D(r)(Ï) and translational D(t)(Ï) contributions to D(Ï). The resulting D(t)(Ï) is described by short-time self-diffusion of effective spheres. Protein self-diffusion at biological volume fractions is found to be slowed down to 20% of the dilute limit solely due to hydrodynamic interactions.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Soroalbumina Bovina
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Substâncias Macromoleculares
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Modelos Químicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article