Ionic strength-dependent denaturation of Thermomyces lanuginosus lipase induced by SDS

Mathias Fanø, Marco van de Weert, Eva Horn Møller, Nanna Aaby Kruse, Sven Frøkjær

    Research output: Contribution to journalJournal articleResearchpeer-review

    11 Citations (Scopus)

    Abstract

    Triglyceride lipase from Thermomyces lanuginosus (TlL) has been reported to be resistant to denaturation by sodium dodecyl sulfate (SDS). We have found that at neutral pH, structural integrity is strongly dependent on ionic strength. In 10 mM phosphate buffer and SDS, the lipase exhibits a far-UV CD spectrum similar to other proteins denatured in this surfactant while the near-UV CD spectrum shows a complete loss of tertiary structure, observations supported by steady state fluorescence spectroscopy. However, when increasing the ionic strength by the addition of NaCl, the lipase was rendered resistant towards SDS denaturation, as observed by all techniques employed. The effect of salt on the critical micelle concentration (CMC) of SDS was observed to correlate with the effect on the degree of SDS-induced denaturation. This finding is compatible with the notion that the concentration of SDS monomers is a crucial factor for SDS–lipase interactions. The presented results are important for the understanding and improvement of protein stability in surfactant systems.
    Original languageEnglish
    JournalArchives of Biochemistry and Biophysics
    Volume506
    Issue number1
    Pages (from-to)92-98
    ISSN0003-9861
    DOIs
    Publication statusPublished - 2011

    Keywords

    • Former Faculty of Pharmaceutical Sciences

    Cite this