The University of Queensland, Brisbane, Australia
Seed storage albumins are degraded during germination to provide nutrients for the seedling. An unusual albumin precursor in the common sunflower Helianthus annuus contains a 14-residue sequence insert that during processing is cleaved out and head-
to-tail cyclized. The resultant peptide is known as Sunflower Trypsin Inhibitor-1, SFTI-1.
We have shown that SFTI-1 is part of a large family of diverse peptides that have hijacked the albumin gene and its processing machinery, creating a short cut for de novo protein evolution. NMR spectroscopy studies have provided novel insights into the
structural features of these unique peptides and their precursors.
