Putative synaptic vesicle nucleotide transporter identified as glyceraldehyde-3-phosphate dehydrogenase.
Synaptic vesicles isolated from electric ray electric organ have been shown previously to contain a 34-kDa protein that binds azido-ATP, azido-AMP, and N-ethylmaleimide. The protein was found to share similarities with the mitochondrial ADP/ATP carrier and assumed to represent the synaptic vesicle nucleotide transporter. Synaptic vesicles were purified by sucrose density gradient centrifugation and subsequent chromatography on Sephacryl S-1000 from both Torpedo electric organ and bovine brain cerebral cortex. They contained ATP-binding proteins of 35 kDa and 34 kDa, respectively. ATP binding was inhibited by AMP. Both proteins were highly enriched after column chromatography of vesicle proteins on AMP-Sepharose. Antibodies were obtained against both proteins. Antibodies against the bovine brain synaptic vesicle protein of 34 kDa bound specifically to the 35-kDa protein of Torpedo vesicles. An N-terminal sequence obtained against the 34-kDa protein of bovine brain synaptic vesicles identified it as glyceraldehyde-3-phosphate dehydrogenase. The previously observed molecular characteristics of the putative vesicular nucleotide transporter in Torpedo fit those of glyceraldehyde-3-phosphate dehydrogenase. We, therefore, suggest that the protein previously identified as putative nucleotide transporter is, in fact, glyceraldehyde-3-phosphate dehydrogenase.
Schläfer
M
M
Zoologisches Institut, Biozentrum, J. W. Goethe-Universität, Frankfurt am Main, Germany.
Volknandt
W
W
Zimmermann
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D001921:Brain / Q000378:metabolism; D002417:Cattle; D002499:Centrifugation, Density Gradient; D002846:Chromatography, Affinity; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis* / Q000502:physiology; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000493:pharmacokinetics*; D013572:Synaptic Vesicles / Q000201:enzymology* / Q000378:metabolism / Q000502:physiology; D014101:Torpedo
D009711:Nucleotides; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases