Medicinal Chemistry and Chemical Biology, Poster
Chemical Synthesis of Pollen Tube Attractant, Tf LURE1 protein
S. Oishi1, N. Kamiya2, M. Kanaoka2, T. Higashiyama1,2, J. W. Bode1,3*
1Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Japan, 2Graduate School of Science, Nagoya University, Japan, 3Laboratorium für Organische Chemie ETH-Zürich, Switzerland
LURE proteins play important role in plant reproduction. Ovules express and secrete LURE proteins to attract male pollen tubes for fertilization.1 Amino acid sequences of LURE proteins vary widely in plant species. Thus, LURE proteins would be one of the keys of species-specific reproduction in plant.

TfLURE1 protein found in Torenia fournieri, has 6 cysteine residues in 62 amino acids. These cysteine form disulfide bonds that is essential for the bioactivity. We report chemical synthesis of TfLURE1 using a-ketoacid-hydroxylamine (KAHA) ligation.2

Peptide segments were synthesized by Fmoc solid phase peptide synthesis. Segment 1, TfLURE1 (1-21), has a-ketoacid at the C-terminus. Segment 2, TfLURE1 (22-61), bears 2-oxaproline at its N-terminus (Scheme 1). KAHA ligation between these two peptide segments gave synthetic TfLURE1 protein (Ser22Hse). After the refolding process with redox buffer, the obtained synthetic protein exhibited comparable bioactivity to the recombinant proteins in bioassay. We will also report synthesis of an ortholog protein, TcLURE1 and their chimeric proteins.
[1] Okuda, S., Tsutsui, H., Shiina, K., Higashiyama, T. et al., Nature 2009 458, 357.
[2] Rohrabacher, F., Wucherpfennig, T. G., Bode, J. W., Top. Curr. Chem., 2015, 363, 1.