Antifreeze activity enhancement by site directed mutagenesis on an antifreeze protein from the beetle Rhagium mordax

Dennis Steven Friis, Erlend Kristiansen, Hans Ramløv, Nicolas von Solms

    Research output: Contribution to journalJournal articlepeer-review


    The ice binding motifs of insect antifreeze proteins (AFPs) mainly consist of repetitive TxT motifs aligned on a flat face of the protein. However, these motifs often contain non-threonines that disrupt the TxT pattern. We substituted two such disruptive amino acids located in the ice binding face of an AFP from Rhagium mordax with threonine. Furthermore, a mutant with an extra ice facing TxT motif was constructed. These mutants showed enhanced antifreeze activity compared to the wild type at low concentrations. However, extrapolating the data indicates that the wild type will become the most active at concentrations above 270 μmol.
    Original languageEnglish
    JournalF E B S Letters
    Issue number9
    Pages (from-to)1767-1772
    Publication statusPublished - 2 May 2014


    • Antifreeze protein
    • Site directed mutagenesis
    • Thermal hysteresis

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