Scientists from the Universities of Western Australia and Queensland, have discovered an unusual enzyme, Asparaginyl endopeptidase (AEP) which apart from its protein-cutting abilities, has also evolved to glue proteins together. This enzyme was discovered in the Sunflower plant.
The seeds of the sunflower plant contains a 14-residue, backbone-macrocyclic peptide, sunflower trypsin inhibitor 1(SFTI-1) which needs the AEP enzyme for its maturation from its precursor state. By using artificial proteins that mimic this 14-residue parent molecule, these scientists have discovered the pathway by which AEP enzymes convert these parent molecular ‘string’ into a small, stable ‘bracelet-like’ protein ring. This study was published in the journal Chemistry & Biology.
To confirm that the AEP enzyme could not only cut- but also ligate, they produced recombinant AEPs in E.coli and these could catalyze both a cleavage reaction and cleavage-dependent, intramolecular transpeptidation to create SFTI-1. “The reaction isn’t really ligation as the energy for…
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