Influx of neutral amino acids across the brush border of rabbit ileum

摘要: Abstract The influxes of the l - and d -stereoisomers alanine, valine, serine, leucine, histidine, phenylalanine tryptophan across brush border rabbit ileum roles α-carboxylate α-amino groups in influx process have been examined. Our results indicate that: 1. interactions between neutral amino acids mechanism(s) invovle as well side chain. 2. requirement for both that their with mechanism are cooperative rather than independent. 3. With exception -valine, all -amino examined display saturation kinetics, Na+-dependent subject to classical competitive inhibition by -enantiomorphs. -valine appears be largely attributable simple diffusion, although a small mediated component characterized high K 1 cannot excluded. 4. When interact mechanisms, chain is displaced 180 degrees from “natural” position, ability mechanisms depend upon engage neighboring groups.