Metacaspase type II : Biochemical studies of the activation anddegradation process of calcium-independentmetacaspase type II from Arabidopsis thaliana

Sammanfattning: Proteases are found in all living kingdoms and are absolute essential for a functional cell to beable to break down peptide bonds. Metacaspases are proteases with the ability to cleave afterarginine and lysine residues. Research that has been done so far on a specific subgroup ofmetacaspases called Metacaspase-IIf from Arabidopsis thaliana (AtMCA-IIf), has shown thatan autocleavage is necessary for the activation process and it will then start to degrade itself.In this project the amino acids which is necessary for the activation and degradation ofAtMCA-IIf has tried to be identified. Based on the predictions of an already determined crystal structure, mutations were produced to generate a more long-lived enzyme. Biochemicalstudies involving activity-and stability assays were performed to get a better understanding ofthe wild type and mutant. The amino acids thought to have an important role in these processes turned out to not have the effect on the enzyme as was predicted, but the experimentsalso did show interesting results.