Evidence for a dipeptide porter in the lysosome membrane.
Small neutral dipeptides such as Gly-Gly are known to cross the lysosome membrane rapidly. The mode of dipeptide translocation was studied, using an osmotic-protection method. Results with dipeptide analogues, such as omega-amino aliphatic acids and taurine, indicated that dipeptides do not cross the rat liver lysosome membrane by unassisted diffusion. Using seven pairs of dipeptide stereoisomers, the penetration of the L-isomer was always found to be much more rapid than that of the D-analogue. It is concluded that the lysosome membrane contains a porter that recognizes and transports L-dipeptides.
Bird
S J
SJ
Department of Biological Sciences, University of Keele, U.K.
Lloyd
J B
JB
D000118:Acetylglucosaminidase / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000201:enzymology; D006596:Hexosaminidases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008247:Lysosomes / Q000201:enzymology*; D051381:Rats; D013237:Stereoisomerism
D006596:Hexosaminidases; D000118:Acetylglucosaminidase