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(Last
modification: 26. Jan.
2009)
Pinus strobus
Branch of an Eastern White Pine (Pinus strobus)
© Armin
Jagel, Botanischer Garten, Ruhr-Universität Bochum
General information on Pinus strobus,
in Wikipedia:
English:
Eastern White Pine
Deutsch:
Weymouths-Kiefer
Go to
Pinosylvin
Our publication on the stilbene
synthases from this tree:
-
Raiber,
S., Schröder, G. and Schröder, J.:
Molecular and enzymatic characterization of
two stilbene synthases from Eastern white pine (Pinus strobus): a
single Arg/His difference determines the activity and the pH dependence of the
enzymes.
FEBS Letters 361, 299-302 (1995).
Pinus strobus (Eastern white pine) contains stilbenes
biosynthetically derived from cinnamoyl-CoA (pinosylvin) or dihydrocinnamoyl-CoA
(dihydropinosylvin). We screened a P. strobus cDNA library with a
stilbene synthase (STS) probe from Pinus sylvestris. The eight
isolated cDNAs represented two closely related STS genes with five amino acid
differences in the proteins. The enzyme properties were investigated after
heterologous expression in Escherichia coli. Both proteins
preferred cinnamoyl-CoA against dihydrocinnamoyl-CoA and thus represented
pinosylvin synthases. Otherwise they revealed large differences. STS1 had only
3-5% of the activity of STS2, its pH optimum was shifted to lower values (pH 6),
and it synthesized with cinnamoyl-CoA a second unknown product. Site-directed
mutagenesis demonstrated that a single Arg-to-His exchange in STS1 was
responsible for all of the differences. The proton acceptor properties of His
are discussed as the reason for the properties of STS1.
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File History:
- 26.01.2009: Link to
pinosylvin discovery
.
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