Abstract
There have recently been advances in methods for detecting local secondary structures of membrane protein using electron paramagnetic resonance (EPR). A three pulsed electron spin echo envelope modulation (ESEEM) approach was used to determine the local helical secondary structure of the small hole forming membrane protein, S21 pinholin. This ESEEM approach uses a combination of site-directed spin labeling and 2H-labeled side chains. Pinholin S21 is responsible for the permeabilization of the inner cytosolic membrane of double stranded DNA bacteriophage host cells. In this study, we report on the overall global helical structure using circular dichroism (CD) spectroscopy for the active form and the negative-dominant inactive mutant form of S21 pinholin. The local helical secondary structure was confirmed for both transmembrane domains (TMDs) for the active and inactive S21 pinholin using the ESEEM spectroscopic technique. Comparison of the ESEEM normalized frequency domain intensity for each transmembrane domain gives an insight into the α-helical folding nature of these domains as opposed to a π or 310-helix which have been observed in other channel forming proteins.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.