LASSO PEPTIDES AS SCAFFOLDS FOR PEPTIDE GRAFTING

摘要

The present invention provides novel templates for peptide grafting. The template is a modified lasso peptide wherein an amino acid sequence of the wildtype lasso peptide comprising one to five amino acids is substituted by another amino acid sequence comprising one to five amino acids. In the modified lasso peptides according to the present invention, any site of the wildtype lasso peptide can be substituted by another amino acid sequence com- prising one to five amino acids. The term "another amino acid sequence" refers to any amino acid sequence that differs from the amino acid sequence of the respec- tive site in the wildtype lasso peptide. The modified lasso peptides according to the present invention are produced by applying the natural maturation machinery for the processing of lasso peptide pre- cursor variants. These variants are generated on the DNA level of the precursor genes by site-directed mutagenesis. The lasso peptide precursor proteins are het- erologously coexpressed with the two processing enzymes and the ex- port/immunity protein which transform the precursor into the modified lasso variant that is secreted into the culture supernatant from which the modified lasso peptide is extracted and purified. The modified lasso peptides according to the present invention can be used for peptide grafting.