Karine Kappaun

Dr. Karine Kappaun


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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KKKarine Kappaun
Karine Kappaun
AMAnne Helene Souza Martinelli
Anne Helene Souza Martinelli
VBValquiria Broll
Valquiria Broll
Barbara ZambelliBarbara Zambelli
Barbara Zambelli
FLFernanda Cortez Lopes
Fernanda Cortez Lopes
Stefano CiurliStefano Ciurli
Stefano Ciurli
Ureases from different biological sources display non-ureolytic properties that contribute to plant defense, in addition to their classical enzymatic urea hydrolysis. Antifungal and entomotoxic effects were demonstrated for Jaburetox, an intrinsically disordered polypeptide derived from jack bean (Canavalia ensiformis) urease. Here we describe the properties of Soyuretox, a polypeptide derived from soybean (Glycine max) ubiquitous urease. Soyuretox was fungitoxic to Candida albicans, leading to the production of reactive oxygen species. Soyuretox further induced aggregation of Rhodnius prolixus hemocytes, indicating an interference on the insect immune response. No relevant toxicity of Soyuretox to zebrafish larvae was observed. These data suggest the presence of antifungal and entomotoxic portions of the amino acid sequences encompassing both Soyuretox and Jaburetox, despite their small sequence identity. Nuclear Magnetic Resonance (NMR) and circular dichroism (CD) spectroscopic data revealed that Soyuretox, in analogy with Jaburetox, possesses an intrinsic and largely disordered nature. Some folding is observed upon interaction of Soyuretox with sodium dodecyl sulfate (SDS) micelles, taken here as models for membranes. This observation suggests the possibility for this protein to modify its secondary structure upon interaction with the cells of the affected organisms, leading to alterations of membrane integrity. Altogether, Soyuretox can be considered a promising biopesticide for use in plant protection.