[Phosphorylation of D-and L-amino-acids by the ileal mucosa in relation with calcium absorption (author's transl)].
L-amino-acids and D-amino-acids were compared firstly for their effects on calcium absorption in ileal loops, and secondly for their ability to be phosphorylated with an ileal mucosa extract. Some molecules, such as D- and L-lysine, D and L-ornithine which are highly effective in enhancing calcium absorption, were also phosphorylable. In contrast, other molecules, such as, D- and L-norleucine, D- and L-valine, are ineffective and are also not phosphorylable. Transphosphorylation rate from ATP of both D- and L-lysine was found to be pH dependent, with a maximum at pH 8.5; at pH 10, no phosphorylation was observed. Among various nucleotides tested (ATP, CTP, GTP, ITP, UTP) which act as phosphate donors, only ATP was able to induce formation of the phosphorylated compounds with D- and L-lysine at pH 8.5.
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D007082:Ileum / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D009711:Nucleotides / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats
D000596:Amino Acids; D009711:Nucleotides; D002118:Calcium
Phosphorylation d'acides D- et L-aminés par la muqueuse iléale en relation avec l'absorption du calcium.