A hydrodynamic study with quasielastic light scattering and sedimentation of bacterial elongation factor EF-Tu · guanosine-5′-diphosphate complex under nonassociating conditions
✍ Scribed by Tom Sam; Michel Mandel; Cornelis Pley
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1990
- Tongue
- English
- Weight
- 721 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
SYNOPSIS
The hydrodynamics of the bacterial elongation factor EF-Tu have been studied in the presence of its ligand guanosine-5'-diphosphate ( GDP ) by sedimentation in the ultracentrifuge and quasielastic light scattering. Sedimentation studies have made it possible to establish experimental conditions under which only negligible aggregation of the protein occurs (neutral pH, concentration < 3 mg/mL) . Analysis of the light intensity autocorrelation functions under these conditions revealed two independent scattering species with diffusion coefficients of 0.71 X cm2 C1. The material with the lower diffusion coefficient, i.e., the aggregates, represented less than 1% of the total number of EF-Tu particles. The other 99% diffused as monomeric molecules with a molar mass corresponding to the value calculated from the known primary structure of the protein. The hydrodynamic parameters derived from the experimental data suggest that EF-Tu -GDP in solution is close to a spherical particle. and 0.04 X N. (1973)