Structures and ligand binding of all-alpha-helical lipid binding proteins from nematodes

BRIAN SMITH; MARÍA FLORENCIA REY; MARINA IBAÑEZ SHIMABUKURO; MADS GABRIELSEN; KATE GRIFFITHS; GISELA R. FRANCHINI; ALAN COOPER; BETINA CÓRSICO; MALCOLM W. KENNEDY

La Plata

Congreso; 8th International Conference on Lipid Binding Proteins, 3-6 de Noviembre de 2013, La Plata, Buenos Aires; 2013

We have elucidated the three dimensional structures of members of two classes of all-alpha-helical lipid binding proteins from parasitic nematodes and studied their lipid binding properties. ABA-1A, a unit from the nematode polyprotein antigen of Ascaris suum displays an unusual fold with two ligand binding cavities facing in opposite directions, each capable of binding at least one fatty acid molecule. In contrast, FAR-1 from Necator americanus (Na-FAR-1) has a compact fold similar to Ce-FAR-7, but with apparently different ligand binding characteristics. Na-FAR-1 has a large internal cavity that can bind multiple ligand molecules simultaneously and can do so with relatively small conformational changes of the protein backbone. We have used NMR spectroscopy to investigate the stoichiometry of ligand binding.