Methods for studying interactions of detergents and lipids with ?-helical and ?-barrel integral membrane proteins.

ABSTRACT: Methods for studying interactions of protein with lipids and detergents are described for representatives of two major classes of membrane proteins: (1) the ?-helical hetero-oligomeric integral cytochrome b6 f complex of oxygenic photosynthesis from cyanobacteria, and (2) the outer membrane ?-barrel proteins BtuB and OmpF from Gram-negative Escherichia coli bacteria. Details are presented on the use of detergents for purification and crystallization of the b6 f complex as well as a method for lipid exchange. The positions of detergent and lipid molecules, which define eight potential lipid-binding sites in the b6 f complex, are described. Differences in detergent strategies for isolation and crystallization of ?-barrel proteins relative to those for oligomeric helical membrane proteins are discussed, and purification and assessment of protein quality by circular dichroism (CD) is presented.

SUBMITTER: Saif Hasan S 

PROVIDER: S-EPMC4062877 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature