Chapter 2. Folding and Stability of Monomeric β-Barrel Membrane Proteins

Summary

This chapter contains sections titled:

• Introduction

• Stability of β-Barrel Membrane Proteins

  • Thermodynamic Stability of FepA in Detergent Micelles

  • Thermodynamic Stability of OmpA in Phospholipids Bilayers

  • Thermal Stability of FhuA in Detergent Micelles

• Insertion and Folding of Transmembrane β-Barrel Proteins

  • Insertion and Folding of β-Barrel Membrane Proteins in Micelles

  • Oriented Insertion and Folding into Phospholipid Bilayers

  • Assemblies of Amphiphiles Induce Structure Formation in β-Barrel Membrane Proteins

  • Electrophoresis as a Tool to Monitor Insertion and Folding of β-Barrel Membrane Proteins

  • pH and Lipid Headgroup Dependence of the Folding of β-Barrel Membrane Proteins

• Kinetics of Membrane Protein Folding

  • Rate Law for β-Barrel Membrane Protein Folding and Lipid Acyl Chain Length Dependence

  • Synchronized Kinetics of Secondary and Tertiary Structure Formation of the β-Barrel OmpA

  • Interaction of OmpA with the Lipid Bilayer is Faster than the Formation of Folded OmpA

• Folding Mechanism of the β-Barrel of OmpA into DOPC Bilayers

  • Multistep Folding Kinetics and Temperature Dependence of OmpA Folding

  • Characterization of Folding Intermediates by Fluorescence Quenching

  • The β-Barrel Domain of OmpA Folds and Inserts by a Concerted Mechanism

• Protein–Lipid Interactions at the Interface of β-Barrel Membrane Proteins

  • Stoichiometry of the Lipid–Protein Interface

  • Lipid Selectivity of β-Barrel Membrane Proteins

• Orientation of β-Barrel Membrane Proteins in Lipid Bilayers

  • Lipid Dependence of the β-Barrel Orientation Relative to the Membrane

  • Inclination of the β-Strands Relative to the β-Barrel Axis in Lipid Bilayers

  • Hydrophobic Matching of the β-Barrel and the Lipid Bilayer

• In vivo Requirements for the Folding of OMPs

  • Amino Acid Sequence Constraints for OmpA Folding in vivo

  • Periplasmic Chaperones

  • Insertion and Folding of the β-Barrel OmpA is Assisted by Skp and LPS

  • Role of Omp85 in Targeting or Assembly of β-Barrel Membrane Proteins

• Outlook

• References