Abstract
Dystrophin is essential for skeletal muscle function and confers resistance to the sarcolemma by interacting with cytoskeletal and membrane partners. We investigated here protein-lipid interaction of a five repeat from the central domain of dystrophin (DYS R11-15) also referred as an actin binding domain. In a first step, we demonstrated that DYS R11-15 interacts more strongly with anionic than with zwitterionic small unilamellar vesicles. Using large unilamellar vesicles with different radius and trypsin accessibility assays, we showed that the protein presents different conformation depending on vesicle curvature and lipid nature. Using label-free quantification mass spectroscometry, a protein domain protected from proteolysis in presence of anionic vesicles was observed while a protein domain more accessible to trypsin in the presence of either anionic or zwitterionic vesicles was identified. In a second step, we studied the adsorption behavior of the protein at the air-liquid and lipid-liquid interface in a Langmuir trough. DYS R11-15 displayed a surface activity while maintaining its α-helical secondary structure as shown by PM-IRRAS. At 16mN/m lateral pressure of monolayer lipid film, few protein clusters were observed by AFM, while at 20 and 30mN/m, a striking protein network was formed with both negative and zwitterionic phospholipids. However, image analysis and behaviour of the networks towards trypsination in the trough as revealed by AFM showed that trypsin accessibility to the protein network depends on the surface pressure as well as on the nature of the phospholipid. These results indicate that DYS R11-15 constitutes part of the dystrophin protein for which anchoring and interaction with membrane depend on the packing and the nature of lipids. Such behaviour provides a strong experimental support for a physiological role of dystrophin central domain in contraction-relaxation cycles and dynamics of muscle cells.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
