Biochemistry 1999, 38, 15043-15051
15043
Conformational Stability and Binding Properties of Porcine Odorant Binding Protein Tatiana V. Burova,‡,§ Yvan Choiset,§ Christophe K. Jankowski,| and Thomas Haertle´*,§ Institute of Biochemical Physics of the Russian Academy of Sciences, VaViloV Strasse 28, 117813 Moscow, Russia, Faculte´ des Etudes Supe´ rieures et de la Recherche, UniVersite´ de Moncton, Moncton, New Brunswick, Canada E1A3E9, and Laboratoire d’Etude des Interactions des Mole´ cules Alimentaires, Institut National de la Recherche Agronomique, BP 71627, 44316 Nantes Cedex 03, France ReceiVed April 2, 1999; ReVised Manuscript ReceiVed August 5, 1999 ABSTRACT: Apparently homogeneous odorant binding protein purified from pig nasal mucosa (pOBP) exhibited subunit molecular masses of 17 223, 17 447, and 17 689 (major component) Da as estimated by ESI/MS. According to gel filtration, this protein, its truncated forms, and/or its variants are homodimeric under physiologic conditions (pH 6-7, 0.1 M NaCl). The dimer S monomer equilibrium shifts toward a prevalent monomeric form at pH
