If you are interested in doing your master projects/exam work within the cyclotide project you can find some possible projects described below. These are all directly involved in our research, and during the past semesters, several of the exam works have led directly to published articles in scientific journals.
Chemical synthesis of cyclotides and cyclotide mutants
The overall aim of this project is to determine which residues that are important for the biological effects of cyclotides, and to use that knowledge for the design of cyclotide mutants. Microwave assisted solid phase peptide chemistry is used for synthesis. Synthesised peptides are then assayed for biological activity, e.g. for antimicrobial and cytotoxic effects. In addition, they will also be subject for folding studies.
Isolation of novel cyclotides
The aim of this project is to explore the structural limits of the cyclotides. In addition, this project will add to the knowledge about cyclotide distribution in plants. Primarily, cyclotides will be isolated from species belonging to the Violaceae and Rubiaceae plant families. The project involves methods such as extraction and isolation and structure determination. HPLC is used for isolation and mass spectrometry for identification and sequencing of novel peptides.
Oxidative folding of cyclotides
The biosynthesis of these cyclic and cystine knotted peptides is still in many parts unknown. This project aims to characterize the reductive unfolding and oxidative folding of disulfide bonds in vitro. The expected outcome is a detailed description of the pathway from the cyclic backbone to its cystine knotted counterpart. The methods used are reduction/oxidation of disulfides in different bufferts, monitoring different species with HPLC and LC-MS, followed by specific labeling and identification by mass spectrometry.
Discovery and design of novel antimicrobial peptides
Currently, we are actively searching for new antimicrobial peptides, in plants and animals. Circular and/or disulfide rich peptides are in focus in several projects. Peptides are isolated, and characterized (sequenced) in small amounts, and then we turn to solid phase peptide synthesis to get material enough for assays and further structural characterization.