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Functional and phylogenetic importance of enzymes in spider venom

Author Nicolas LANGENEGGER
Director of thesis Prof. Dr. Wolfgang Nentwig
Co-director of thesis
Summary of thesis

During hunting, most spiders rely on their highly effective venom mainly comprising peptides and proteins evolved during the last million years. In contrary to spider venom peptides, spider venom enzymes are only marginally investigated today.

This work includes characterization and identification of spider venom key enzymes by a combination of the isolation from the venom of a model organism, and the analysis of venom gland transcriptomes of up to 50 spider species.

Enzyme purification and characterization will be done from the venom of the easy-to-bread spider C.salei. Thereby the first focus will lay on the isolation of a highly specific serine protease involved in the maturing process of venom peptides. This will be done by a combination of different chromatographic methods and the use of specific peptide substrates in a FRET based activity test.

In a second step, enzymatic activity tests for other venom enzymes will be developed and applied for isolation of enzymes from C.salei venom and screening of other spider venoms for specific activity.

The proteomic data of C.salei venom enzymes will be used as reference to identify corresponding enzyme sequences in the transcriptome of other spiders. Together with existing information about other venom components, the transcriptome data will also be analyzed in a phylogenetic context.

The functional importance of the identified key enzymes on the effectivity of the venom may be analyzed in Drosophila bioassays by coinjection of isolated or recombinant enzymes with C.salei main toxins CsTx-1 and cupiennin 1a.


Administrative delay for the defence
URL http://ecol.iee.unibe.ch/content/index_eng.html