ISSN:
1432-072X
Keywords:
Key words Glutamine
;
Amino acid transport
;
Solute
;
uptake
;
Corynebacterium glutamicum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Corynebacterium glutamicum took up glutamine by a sodium-dependent secondary transport system. Both the membrane potential and the sodium gradient were driving forces. Glutamine uptake showed Michaelis-Menten kinetics, with a K m of 36 μM and a V max of 12.5 nmol min–1 (mg dry weight)–1 at pH 7. Despite a pH optimum in the alkaline range around pH 9, it was shown that uncharged glutamine is the transported species. The affinity for the cotransported sodium was relatively low; an apparent K m of 1.4 mM was determined. Among various substrates tested, only asparagine, when added in 50-fold excess, led to an inhibition of glutamine transport. It was concluded that glutamine uptake occurs via a specific transport system in symport with at least one sodium ion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002030050240
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