The kinetics of glutamine transport in bovine lymphocytes.
The transport of glutamine was examined in bovine peripheral lymphocytes which had been cultured in the presence or absence of Concanavalin A (Con A). Glutamine transport was mediated by a triphasic transport system in both cell populations. The calculated kinetic parameters were: Km 1.0, 4.7 and 12.7 mM and Vmax 4.5, 6.0 and 9.0 nmol/min per mg protein respectively. Con A augmented the capacity rather than the affinity of the glutamine transport systems (Vmax rates being 8.0, 12.2 and 38.0 nmol/min per mg protein respectively). Transporter I displayed Michaelis-Menton kinetics, while transporters II and III were co-operative carriers possessing Hill coefficients of 2.3 and 9.5 respectively. Preliminary studies using amino acid and ion inhibition studies suggested that transporter I was a system ASC-type carrier, transporter III a system L carrier, while the nature of transporter II was unclear.
Piva
T J
TJ
Department of Chemistry and Biochemistry, James Cook University, Townsville, Queensland, Australia.
McCabe
M G
MG
McEvoy-Bowe
E
E
D000818:Animals; D002250:Carbon Radioisotopes; D002417:Cattle; D002478:Cells, Cultured; D003208:Concanavalin A; D005973:Glutamine / Q000493:pharmacokinetics*; D008214:Lymphocytes / Q000378:metabolism*
D002250:Carbon Radioisotopes; D005973:Glutamine; D003208:Concanavalin A