title: Mass spectrometrical analysis of bilin-binding protein from the wing of Hebomoia glaucippe (Linnaeus, 1758) (Lepidoptera: Pieridae).
abstract: Bilin-binding protein (BBP) is a member of the lipocalin superfamily and a pigment protein in Lepidoptera. It is binding to a series of lipidic compounds but its functions remain to be elucidated. Working on wing proteins in Hebomoia glaucippe, we observed this protein on gels and decided to characterize BBP. A gel-based mass spectrometrical method using two-dimensional gel electrophoresis followed by in-gel digestion of protein spots followed by nano-LC-ESI-MS/MS (ion trap, HCT) identification and characterization of proteins was applied. An antibody was generated against the protein and immunoblotting in the butterfly and mouse brain was carried out. Two spots were identified from the butterfly wing as BBP (P09464) with high sequence coverage. Nitrotyrosination (Y163; as aminotyrosine) was observed and nitration was verified using immunoblotting. Additional posttranslational modifications (PTMs) as hypusine, carboxylation, kynurenine, aminoadipic acid, were proposed. The presence of BBP-immunoreactive protein was also observed in mouse brain. The characterization of BBP showed high sequence similarity with mouse apolipoprotein D and the findings suggest a tentative function of BBP comparable to apolipoproteins. The role of the PTMs remains elusive but nitration, in analogy to nitration effects reported in literature, proposes a role for mechanoelastic proteins and protein-protein interactions.
authors: Department of Pediatrics, Medical University of Vienna, Vienna, Austria.
authors: Narkhyun
authors: N
authors: Bae
authors: Martin
authors: M
authors: Lödl
authors: Arnold
authors: A
authors: Pollak
authors: Gert
authors: G
authors: Lubec
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D053399:Apolipoproteins D / Q000737:chemistry; D015153:Blotting, Western; D001923:Brain Chemistry; D002080:Butterflies / Q000737:chemistry*; D002352:Carrier Proteins / Q000032:analysis / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D019476:Insect Proteins / Q000032:analysis / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000737:chemistry; D014921:Wings, Animal / Q000737:chemistry*
chemical_list: D053399:Apolipoproteins D; D002352:Carrier Proteins; D019476:Insect Proteins; C053849:bilin-binding protein, insect; C002744:3-nitrotyrosine; D014443:Tyrosine; D008239:Lysine