ISSN:
1432-2048
Keywords:
1,6-Di-O-galloyl-β-d-glucose
;
Gallotannin biosynthesis
;
6-O-Galloyl-β-d-glucose
;
Galloyltrans-ferase
;
Rhus
;
1,2,6-Tri-O-galloyl-β-d-glucose
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Cell-free extracts from leaves of Rhus typhina L. (sumach) were found to transfer the 1-O-galloyl moiety of l,6-di-O-galloyl-β-d-glucose to the 2-position of the same compound, yielding 1,2,6-tri-O-galloyl-β-d-glucose and leaving 6-O-galloylglucose as the deacylated by-product. The enzyme catalyzing this ‘disproportionation’ was purified almost 1700-fold. It had a molecular weight of approx. 56 000, a K m value of 11.5 mM, was stable between pH 4.5 and 6.5, and most active at pH 5.9 and 40° C. The systematic name “1,6-di-O-galloyl-glucose: 1,6-di-O-galloylglucose 2-O-galloyltransferase” (EC 2.3.1.) was proposed for this new enzyme whose detection provided evidence that, in addition to β-glucogallin (1-O-galloyl-β-d-glucose), higher substituted glucose esters also have the potential to serve as acyl donors in the biosynthesis of gallotannins.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00197959
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