Multicomponent analysis of amino acid transport System L in normal and virus-transformed fibroblasts.
Amino acid transport System L in both normal Balb/c 3T3 cells and in those transformed with simian virus 40 (SV 3T3) was analysed kinetically under two different experimental conditions. Under 'zero-trans' conditions the results for both types of cell could be interpreted satisfactorily in terms of System L consisting of two components (L1 and L2) characterized by different Km values. This conclusion is in agreement with previous reports. However, under 'infinite-trans' conditions, the experimental data could not be accounted for in terms of only two components; the introduction of a third component (L3) was necessary to provide a satisfactory fit. Viral transformation affects only the L1 component, either by modification or by replacement, giving it a higher 'affinity' (lower Km) but a lower 'capacity' (lower Vmax).
Gandolfi
S A
SA
Istituto di Oftalmologia Università di Parma, Italy.
Maier
J A
JA
Petronini
P G
PG
Wheeler
K P
KP
Borghetti
A F
AF
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D001692:Biological Transport; D002460:Cell Line; D002472:Cell Transformation, Viral; D005347:Fibroblasts / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D010649:Phenylalanine / Q000378:metabolism; D013539:Simian virus 40
D000596:Amino Acids; D010649:Phenylalanine