The structure and diffusion behaviour of the neurotransmitter - aminobutyric acid (GABA) in neutral aqueous solutions
GABA ( -aminobutyric acid) is a non-protein amino acid with important physiological properties, and with considerable relevance to the food and pharmaceutical industries. Particular interest has focused on its role as an inhibitory neurotransmitter in the mammalian cerebral cortex. In this paper, we...
- Autores:
- Tipo de recurso:
- Fecha de publicación:
- 2017
- Institución:
- Universidad de Bogotá Jorge Tadeo Lozano
- Repositorio:
- Expeditio: repositorio UTadeo
- Idioma:
- OAI Identifier:
- oai:expeditiorepositorio.utadeo.edu.co:20.500.12010/9083
- Acceso en línea:
- http://dx.doi.org/10.1016/j.jct.2016.09.014
http://hdl.handle.net/20.500.12010/9083
- Palabra clave:
- Diffusion coefficient
Density
Activity coefficient
Aminobutyric acid
Solutions
Taylor dispersion
NMR
Soluciones (Química) -- Investigaciones
Aminoácidos -- Investigaciones
- Rights
- License
- Abierto (Texto Completo)
Summary: | GABA ( -aminobutyric acid) is a non-protein amino acid with important physiological properties, and with considerable relevance to the food and pharmaceutical industries. Particular interest has focused on its role as an inhibitory neurotransmitter in the mammalian cerebral cortex. In this paper, we report density and mutual diffusion coefficients of GABA in non-buffered aqueous solutions (0.001 to 0.100) mol·dm-3 at 298.15 K. Under these conditions, 1H and 13C NMR spectroscopy and pH measurements show that it is present predominantly as a monomeric zwitterionic species. Diffusion coefficients have been computed assuming that this behaves as the binary system GABA/water. From density and intermolecular diffusion coefficients measurements, the molar volume, hydrodynamic radii Rh, diffusion coefficients at infinitesimal concentration D0, activity coefficients and the thermodynamic factors, FT, have been estimated. Within experimental error, the hydrodynamic volume calculated from this is identical to the molar volume obtained from density measurements. From the NMR spectra and literature data, it is suggested that this amino acid diffuses in aqueous solution as a curved, coil-like hydrated zwitterionic entity. |
---|