The human intestinal H+/oligopeptide cotransporter hPEPT1 transports differently-charged dipeptides with identical electrogenic properties.
The human intestinal H+/oligopeptide cotransporter hPEPT1, expressed in Xenopus oocytes, transported neutral, anionic and cationic dipeptides with identical electrogenic properties and maximal evoked currents. Currents were activated by 1 H+ regardless of the net charge on the driven substrate, and were independent of Na+o, K+i and Clo-, calling into question the familiar concept of the origin of the transporter-mediated current.
Mackenzie
B
B
Department of Physiology, UCLA School of Medicine 90095-1751, USA.
Fei
Y J
YJ
Ganapathy
V
V
Leibach
F H
FH
D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis / Q000502:physiology*; D002712:Chlorides / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D009865:Oocytes / Q000502:physiology; D000074011:Peptide Transporter 1; D011188:Potassium / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D012413:Rubidium / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D027981:Symporters; D014981:Xenopus; D014982:Xenopus laevis
D002352:Carrier Proteins; D002712:Chlorides; D004151:Dipeptides; D009842:Oligopeptides; D000074011:Peptide Transporter 1; D011994:Recombinant Proteins; C082186:SLC15A1 protein, human; D027981:Symporters; D012964:Sodium; D012413:Rubidium; D011188:Potassium