Gandolfi S A, Maier J A, Petronini P G, Wheeler K P, Borghetti A F
Istituto di Oftalmologia Università di Parma, Italy.
Biochim Biophys Acta. 1987 Nov 2;904(1):29-35. doi: 10.1016/0005-2736(87)90083-6.
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).
在两种不同的实验条件下，对正常的Balb/c 3T3细胞以及用猿猴病毒40转化的细胞（SV 3T3）中的氨基酸转运系统L进行了动力学分析。在“零转运”条件下，两种类型细胞的结果都可以用由两个成分（L1和L2）组成的系统L来满意地解释，这两个成分具有不同的Km值。这一结论与先前的报道一致。然而，在“无限转运”条件下，实验数据不能仅用两个成分来解释；必须引入第三个成分（L3）才能得到满意的拟合。病毒转化仅通过修饰或替代影响L1成分，使其具有更高的“亲和力”（更低的Km）但更低的“容量”（更低的Vmax）。
