Nomenclature	Peptide transporter 1	Peptide transporter 2	Peptide transporter 3	Peptide transporter 4
Systematic nomenclature	SLC15A1	SLC15A2	SLC15A3	SLC15A4
Common abreviation	PepT1	PepT2	PHT2	PHT1
HGNC, UniProt	SLC15A1, P46059	SLC15A2, Q16348	SLC15A3, Q8IY34	SLC15A4, Q8N697
Substrates	fMet‐Leu‐Phe [337], cefadroxil [177], valacyclovir [178], cyclacillin [177], muramyl dipeptide [496]	cefadroxil [177], cyclacillin [177]	–	valacyclovir [37]
Endogenous substrates	dipeptides [135], 5‐aminolevulinic acid [135], tripeptides [135]	dipeptides, 5‐aminolevulinic acid, tripeptides	L‐histidine, carnosine, dipeptides, tripeptides	carnosine, L‐histidine, dipeptides, tripeptides
Stoichiometry	2 H+ : 1 zwitterionic peptide (in)	2 H+ : 1 zwitterionic peptide (in)	Unknown	Unknown
Inhibitors	Lys[Z(NO2)]‐Pro (pK i 5) [283], 4‐AMBA [107]	Lys[Z(NO2)]‐Lys[Z(NO2)] [40, 472], Lys[Z(NO2)]‐Pro	–	–
Labelled ligands	[11C]GlySar, [14C]GlySar, [3H]GlySar	[11C]GlySar, [14C]GlySar, [3H]GlySar	[14C]histidine, [3H]histidine	[14C]histidine (Binding) [528], [3H]histidine