The diversity of secondary metabolites is based on a rather limited set of biosynthetic pathways, such as phenylpropanoid or terpenoid biosynthesis. Specialized cells and organs overcome this monotonous set of core structures by expression of specific transcripts and therefore are responsible for the diversity of specialized metabolites at the cell and organ-specific level. Diversification is often initiated by position-specific hydroxylation and further amplified by glycosylation, methylation, and acyltransfer-reactions. Small structural differences of individual enzymes, usually organized in gene families, result in the required fine tuning of position and substrate-specific activities and result in diverse structural and molecular signature of special metabolites, with the observed broad spectrum of functional activities.
Our approach combines classical enzyme and substrate purification and identification with molecular tools and cell-specific visualization techniques. Besides the functional properties of individual substrates and products we are also investigating cell or organ specific distribution of enzymes and identification of transporters, required for proper deposition of cell specific molecules. Our current focus is on:
- Identification and functional characterisation of enzymes in the phenylpropanoid metabolism. Target-oriented design of these enzymes for applications as bioorganic catalysts in the synthesis of relevant natural products. this approach also includes the in vivo functional characterization.
- Cellular and subcellular identification of enzymes and products in vivo.
- Charakterisation of potential substrate-specific transporters.
- Identification, characterization and quantification of cell- und organ-specific phenylpropanoids by spectrometric and chromatographic methods.