首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Ligand binding and self‐association cooperativity of β‐lactoglobulin
Authors:Gabriel Gutiérrez‐Magdaleno  Martiniano Bello  M Carmen Portillo‐Téllez  Adela Rodríguez‐Romero  Enrique García‐Hernández
Institution:1. Instituto de Química Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, , México, D.F., 04630 México;2. Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, , Cuernavaca, Morelos, 62210 México
Abstract:Unlike most small globular proteins, lipocalins lack a compact hydrophobic core. Instead, they present a large central cavity that functions as the primary binding site for hydrophobic molecules. Not surprisingly, these proteins typically exhibit complex structural dynamics in solution, which is intricately modified by intermolecular recognition events. Although many lipocalins are monomeric, an increasing number of them have been proven to form oligomers. The coupling effects between self‐association and ligand binding in these proteins are largely unknown. To address this issue, we have calorimetrically characterized the recognition of dodecyl sulfate by bovine β‐lactoglobulin, which forms weak homodimers at neutral pH. A thermodynamic analysis based on coupled‐equilibria revealed that dimerization exerts disparate effects on the ligand‐binding capacity of β‐lactoglobulin. Protein dimerization decreases ligand affinity (or, reciprocally, ligand binding promotes dimer dissociation). The two subunits in the dimer exhibit a positive, entropically driven cooperativity. To investigate the structural determinants of the interaction, the crystal structure of β‐lactoglobulin bound to dodecyl sulfate was solved at 1.64 Å resolution. Copyright © 2013 John Wiley & Sons, Ltd.
Keywords:protein‐lipid interaction  lipocalin  SDS recognition  isothermal titration calorimetry  crystallography  allostery
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号