tailieunhanh - Báo cáo Y học: Boar salivary lipocalin Three-dimensional X-ray structure and androstenol/androstenone docking simulations

The X-ray structure of variant A of authentic boar salivary lipocalin (SAL), a pheromone-binding protein specifically expressed in the submaxillary glands of the boar, has been solvedandrefinedat A ˚ structuredisplays a classical lipocalin fold with a nine-stranded sandwiched bbarrel and anahelix. | Eur. J. Biochem. 269 2449-2456 2002 FEBS 2002 doi Boar salivary lipocalin Three-dimensional X-ray structure and androstenol androstenone docking simulations Silvia SDinelli1 . Florence Vincent1 Paolo Pelosi2 Mariella Teaoni1 and Christian Cambillau1 1 Architecture et Fonction des Macromolecules Biologiques CNRS and Universités Aix-Marseille I II France 2Dipartimento di Chimica e Biotecnologie Agrarie Universite di Pisa Italy The X-ray structure of variant A of authentic boar salivary lipocalin SAL a pheromone-binding protein specifically expressed in the submaxillary glands of the boar has been solved and refined at A resolution. The structure displays a classical lipocalin fold with a nine-stranded sandwiched b barrel and an a helix. A putative glycosylation site at position 53 has been found to carry a GlcNAc sugar residue. In contrast with what was expected on the basis of mass spectroscopy reports the internal cavity was found to be devoid of bound pheromonal compound androstenone or androstenol . Instead a small electron density volume could be satisfied by a glycerol molecule a component of the cryoprotecting liquor. The internal cavity was revealed to be very small for steroid compound accommodation. Therefore docking and molecular dynamics experiments were performed with both pheromonal compounds. These simulations clearly demonstrate a volume increase of the cavity upon steroid binding and the adaptation of the aminoacid side chains to the steroid molecules. This explains the higher affinity of SAL for both steroid molecules compared to other smaller molecules although no specific interaction is established with either compound. Keywords crystal structure odorant binding protein salivary lipocalin steroid pheromone. Boar salivary lipocalin SAL is a pheromone-binding protein PBP specifically expressed in the submaxillary glands of the boar 1 . While it is produced in very high amounts hundreds of milligrams in the boar s