title: Membrane-bound peptides from V-ATPase subunit a do not interact with an indole-type inhibitor.
abstract: The V-ATPases are ATP-dependent proton pumps, found in virtually all cells, responsible for acidification of organelles and energizing of plasma membranes. Its role in diseases, such as osteoporosis and metastatic cancer, makes the V-ATPase a potential drug target. Short synthetic peptides that are presented here mimic the 7th transmembrane domain (TM7) of subunit a (Vph1p) of Saccharomyces cerevisiae V-ATPase, an essential part of the membrane-bound VO domain, where proton translocation takes place. The peptides adopt a transmembrane configuration only in membranes containing anionic lipids, stressing the importance of strong interfacial anchoring by the flanking lysines. Peptide P1, which contains the essential arginine R735, is monomeric, whereas peptide P2, which lacks this extra charge, tends to aggregate in the membrane. SB 242784, which is a highly potent inhibitor of V-ATPase, does not show any interaction with the peptides, indicating that TM7 alone is not sufficient for inhibitor binding.
authors: Centro de Química-Física Molecular, Instituto Superior Técnico, Lisbon, Portugal.
authors: Renske W
authors: RW
authors: Hesselink
authors: Alexander
authors: A
authors: Fedorov
authors: Marcus A
authors: MA
authors: Hemminga
authors: Manuel
authors: M
authors: Prieto
mesh_terms: D020106:Acrylamide / Q000737:chemistry / Q000494:pharmacology; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D001120:Arginine / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology*; D008051:Lipid Bilayers / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D010880:Piperidines / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D014364:Tryptophan / Q000737:chemistry; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D007211:Indoles; D008051:Lipid Bilayers; D008055:Lipids; D008565:Membrane Proteins; D010455:Peptides; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D010880:Piperidines; C118025:SB 242784; D020106:Acrylamide; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol; D014364:Tryptophan; D001120:Arginine; D025262:Vacuolar Proton-Translocating ATPases; C017251:1,2-oleoylphosphatidylcholine