| Autor: |
Solana, Sonia, Reglero, Ángel, Martı́nez-Blanco, Honorina, Revilla-Nuin, Beatriz, Bravo, Ignacio G, Rodrı́guez-Aparicio, Leandro B, Ferrero, Miguel A |
| Zdroj: |
FEBS Letters; November 2001, Vol. 509 Issue: 1 p41-46, 6p |
| Abstrakt: |
The N‐acetylneuraminic acid (NeuAc) transport system of Pasteurella (Mannheimia) haemolyticaA2 was studied when this bacterium was grown in both complex and chemically defined media. Kinetic measurements were carried out at 37°C in 50 mM Tris–HCl buffer, pH 8.0, containing 50 μg/ml bovine serum albumin. Under these conditions, the uptake rate was linear for at least 3 min and the calculated Kmfor NeuAc was 0.1 μM. The transport rate was increased by the addition of several cations and was inhibited by sodium arsenite (95%), N,N′‐dicyclohexyl‐carbodiimide (50%), and 2,4‐dinitrophenol (40%) at final concentration of 1 mM (each). These results support the notion that NeuAc uptake is an active sugar cation symporter. Study of specificities showed that glucosamine, mannose and mannosamine inhibited the transport of NeuAc in this bacterium. Analysis of expression revealed that the NeuAc transport system was induced by NeuAc and by the simultaneous presence of glucose and galactose in the growth medium. |
| Databáze: |
Supplemental Index |
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