title: A novel fatty acid-binding protein-like carotenoid-binding protein from the gonad of the New Zealand sea urchin Evechinus chloroticus.
abstract: A previously uncharacterized protein with a carotenoid-binding function has been isolated and characterized from the gonad of the New Zealand sea urchin Evechinus chloroticus. The main carotenoid bound to the protein was determined by reversed phase-high performance liquid chromatography to be 9'-cis-echinenone and hence this 15 kDa protein has been called an echinenone-binding protein (EBP). Purification of the EBP in quantity from the natural source proved to be challenging. However, analysis of EBP by mass spectrometry combined with information from the Strongylocentrotus purpuratus genome sequence and the recently published E. chloroticus transcriptome database, enabled recombinant expression of wild type EBP and also of a cysteine61 to serine mutant that had improved solubility characteristics. Circular dichroism data and ab initio structure prediction suggests that the EBP adopts a 10-stranded β-barrel fold consistent with that of fatty acid-binding proteins. Therefore, EBP may represent the first report of a fatty acid-binding protein in complex with a carotenoid.
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Jodi
authors.initials: J
authors.lastname: Pilbrow
authors.affiliation: Centre for Protein Research, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Manya
authors.initials: M
authors.lastname: Sabherwal
authors.affiliation: Monash Institute of Medical Research-Prince Henry's Institute, Monash University, Melbourne, Victoria, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Garama
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Alan
authors.initials: A
authors.lastname: Carne
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002338:Carotenoids / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D050556:Fatty Acid-Binding Proteins; D015870:Gene Expression; D006066:Gonads / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012617:Sea Urchins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; D011994:Recombinant Proteins; D002338:Carotenoids