title: Intramolecular cross-linking in the native JHBP molecule.
abstract: Juvenile hormone binding protein (JHBP) acts as a shuttle, carrying one of the most crucial hormones for insect development to target tissues. We have found that although the JHBP molecule does not contain tryptophan residues, it exhibits a weak fluorescence maximum near 420nm upon excitation at 315nm. Gel filtration experiments performed in denaturing conditions and ESI-MS analyses excluded the possibility that some low molecular ligand was bound to the protein molecules. Further UV and CD spectroscopy studies, as well as immunoblotting, showed that the unusual JHBP optical properties were due to dityrosine intramolecular cross-linking. These bridges were detected both in native and recombinant protein molecules. We believe that in Galleria mellonella hemolymph the DT generation occurs via ROS-mediated oxidation leading to the formation of cross-linked JHBP monomers. MS analyses of peptides generated after JHBP proteolysis indicated, that the dityrosine bridge occurs between the Y128 and Y130 residues.
authors.affiliation: Department of Biochemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Dominika
authors.initials: D
authors.lastname: Bystranowska
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Szewczuk
authors.forename: Marek
authors.initials: M
authors.lastname: Lisowski
authors.forename: Ewa
authors.initials: E
authors.lastname: Sitkiewicz
authors.forename: Piotr
authors.initials: P
authors.lastname: Dobryszycki
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ożyhar
authors.forename: Marian
authors.initials: M
authors.lastname: Kochman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002942:Circular Dichroism; D006458:Hemolymph / Q000737:chemistry / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism*; D007313:Insecta / Q000737:chemistry / Q000378:metabolism*; D007605:Juvenile Hormones / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D019476:Insect Proteins; D007605:Juvenile Hormones; D017382:Reactive Oxygen Species; C035606:juvenile hormone-binding protein, insect; D014443:Tyrosine; C007543:dityrosine