Abstract
We succeeded to purify the acyl-glucose dependent anthocyanin 5-glucosyltransferase (AA5GT) protein from the petals of carnation by the 7 purification steps. On the basis of the partial amino acid sequences, a cDNA encoding AA5GT was isolated by the PCR. The recombinant AA5GT expressed in Escherichia coli showed AA5GT activity. AA5GT gene expression was undetectable in the petals of carnation varieties accumulating the anthocyanin lacking a glucosyl moiety at 5 position. We introduced the AA5GT cDNA construct to the epidermal cells of the petals of the mutant carnation transiently. The fluorescence derived from the anthocyanin molecules modified at 5 position with the glucose was observed, implying that the introduced AA5GT was expressed and catalyzed AA5GT reaction in vivo. We also isolated AAGT homolog cDNA from delphinium petals. Recombinant delphinium AAGT homolog expressed in E. coli showed anthocyanin 7-glucosyltransferase activity. Homology search analysis based on these AAGTs amino acid sequences revealed that AAGTs were belonging to glycoside hydrolase family 1. This research was partially supported by the Research and Development Program for New Bio-industry Initiatives.
