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dc.contributor.advisorPliotas, Christos
dc.contributor.advisorPenedo, Carlos
dc.contributor.authorKapsalis, Charalampos
dc.description.abstractMechanosensation is the ability of cells to sense and respond to mechanical stimuli deriving from their environment. Despite being a fundamental cellular response though, the molecular basis of mechanotransduction is still largely unknown. The mechanosensitive (MS) channel of large conductance, MscL, is expressed by all prokaryotes, it is the MS channel with the highest pressure activation threshold and acts as a last resort safety valve. It responds to the lateral tension of the membrane and, by opening its pore of ≈35Å, it rapidly allows solutes to exit the cell in order to rescue it from lysis during severe hypoosmotic shock. Despite its importance and abundance, the gating and activation mechanism of MscL has not been elucidated. Thus, in the main project presented, MscL’s gating mechanism is investigated as a means to gain insight on the mode of mechanosensation itself. Activation of the channel through site-directed spin labelling (SDSL) reveals that the nano-pockets, transmembrane hydrophobic crevices of the protein, are crucial for the activation of MscL. SDSL at the nano-pockets’ entrance hinders lipid acyl chains from penetrating them and this causes the channel to adopt a more expanded state, as demonstrated by EPR spectroscopy, which is more prone to opening, as revealed by single-molecule electrophysiology. Since MscL is only found in prokaryotes, manipulation of its gating mechanism could lead to the channel being used as a novel form of antibiotic target. Moreover, due to its large pore, it could also be utilized in nanotechnological applications for targeted drug delivery.en_US
dc.publisherUniversity of St Andrews
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivatives 4.0 International*
dc.subjectMechanosensitive channelsen_US
dc.subjectLarge conductanceen_US
dc.subjectElectron paramagnetic resonanceen_US
dc.subjectSite-directed spin labellingen_US
dc.titleInvestigating the gating mechanism of the large conductance mechanosensitive channel by SDSL and EPR spectroscopyen_US
dc.contributor.sponsorUniversity of St Andrews. School of Biologyen_US
dc.contributor.sponsorRoyal Society of Edinburgh (RSE)en_US
dc.contributor.sponsorTenovus Scotlanden_US
dc.contributor.sponsorCarnegie Trust for the Universities of Scotlanden_US
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US
dc.publisher.departmentBiomedical Sciences Research Complex, St Andrewsen_US
dc.rights.embargoreasonThesis restricted in accordance with University regulations. Part (Chapter 4 (all), Chapter 6 (all), Chapter 3 (Section 3.2.7) and Chapter 7(Sections 7.2.2 and 7.2.4)) restricted until 29 October 2022en

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    Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
    Except where otherwise noted within the work, this item's licence for re-use is described as Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International