Symposium “Plants in Health and Culture”
1 Department of Chemistry Gadjah Mada University, Yogyakarta, Indonesia
2 Division of Pharmacognosy, Institute of Biology, Leiden University, Gorlaeus Laboratories, PO Box 9502, 2300 RA Leiden, The Netherlands
3 Current address: Genome Institute of Singapore, 1 Science Park Road, #05-01,The Capricorn, Singapore Science Park II, Singapore 117528
Proteome analysis for studying cannabinoid biosynthesis in Cannabis sativa L.
Cannabinoids are accumulated in the flowering tops of Cannabis sativa, especially in the glands. Accumulation of these metabolites is probably due to tissue specific expression of genes encoding enzymes involved in the biosynthesis. Proteome analysis (proteomics) could be used as a tool to find these genes by comparison of proteins expressed in low abundance cannabinoid tissue (leaves) with flowers. Proteins extracted from leaves and flowers of Cannabis sativa were separated using two-dimensional (2D) gel electrophoresis. Over 800 protein spots were reproducibly resolved in the 2D gels from leaves and flowers. The patterns of the two gels were different and little correlation among the proteins could be observed. Some proteins that were only expressed in flowers were chosen for identification by MALDI-TOF mass spectrometry and peptide mass fingerprint database searching. Comparison also has been made of flower proteome and gland proteome. Only less then half of the proteins expressed in flowers are also expressed in glands. Some selected gland protein spots were identified. Western blotting was employed to identify a polyketide synthase (PKS), an enzyme believed to be involved in cannabinoid biosynthesis, resulting in detection of a single protein. However, lack of data on proteins as well as genes from Cannabis sativa in the available databases seriously hampered the identification of the selected and analyzed proteins.