ALIPHATIC CHAIN-LENGTH SPECIFICITY OF THE POLYAMINE TRANSPORT-SYSTEM IN ASCITES L1210 LEUKEMIA-CELLS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (1) , 126-128
Abstract
A series of diamine homologues of putrescine and triamine homologs of spermidine was used to determine the structural specificity of the polyamine transport system in ascites L1210 leukemia cells by measuring their ability to compete with [3H]-putrescine, [3H]spermidine or [3H]spermine for uptake. Transport specificity among the diamines (as indicated by Ki constants) was greatest for those having chain lengths similar to that of spermidine and least for those similar to putrescine. Among the triamines, transport specificity was greatest for those having an overall chain length similar to those of spermidine and spermine. The homolog competition profiles were relatively the same for [3H]putrescine, [3H]spermidine or [3H]spermine, suggesting that all 3 polyamines utilize the same transport system. This was further substantiated by uptake kinetic plots which showed that the 3 polyamines were competitive inhibitors of one another. In terms of receptor specificity, the ranking order among the polyamines was as follows: spermine (apparent Km, 1.6 .mu.M) > spermidine (apparent Km, 2.2 .mu.M) > putrescine (apparent Km, 8.5 .mu.M). This formation should prove useful in designing anticancer agents which are intended to utilize this transport system.

This publication has 1 reference indexed in Scilit: