title: Computational study of ligand binding in lipid transfer proteins: Structures, interfaces, and free energies of protein-lipid complexes.
abstract: Plant nonspecific lipid transfer proteins (nsLTPs) bind a wide variety of lipids, which allows them to perform disparate functions. Recent reports on their multifunctionality in plant growth processes have posed new questions on the versatile binding abilities of these proteins. The lack of binding specificity has been customarily explained in qualitative terms on the basis of a supposed structural flexibility and nonspecificity of hydrophobic protein-ligand interactions. We present here a computational study of protein-ligand complexes formed between five nsLTPs and seven lipids bound in two different ways in every receptor protein. After optimizing geometries in molecular dynamics calculations, we computed Poisson-Boltzmann electrostatic potentials, solvation energies, properties of the protein-ligand interfaces, and estimates of binding free energies of the resulting complexes. Our results provide the first quantitative information on the ligand abilities of nsLTPs, shed new light into protein-lipid interactions, and reveal new features which supplement commonly held assumptions on their lack of binding specificity.
authors.affiliation: Unidad de Química y Bioquímica, Departamento de Biotecnología, E.T.S.I. Montes, Universidad Politécnica de Madrid, Madrid 28040, Spain. luis.fpacios@upm.es
authors.forename: Luis F
authors.initials: LF
authors.lastname: Pacios
authors.forename: Cristina
authors.initials: C
authors.lastname: Gómez-Casado
authors.forename: Leticia
authors.initials: L
authors.lastname: Tordesillas
authors.forename: Arantxa
authors.initials: A
authors.lastname: Palacín
authors.forename: Rosa
authors.initials: R
authors.lastname: Sánchez-Monge
authors.forename: Araceli
authors.initials: A
authors.lastname: Díaz-Perales
mesh_terms: D052179:Antigens, Plant / Q000737:chemistry*; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry*; D008024:Ligands; D056004:Molecular Dynamics Simulation; D010940:Plant Proteins / Q000737:chemistry*; D011487:Protein Conformation; D012995:Solubility; D013816:Thermodynamics
chemical_list: D052179:Antigens, Plant; D002352:Carrier Proteins; D008024:Ligands; D010940:Plant Proteins; C511920:lipid transfer proteins, plant