Websites of the Schröder Group

Level up
Sirtuins: Structure, Enzyme Activities, Functions
Sirtuin Activators: Resveratrol etcet.
Sirtuin Inhibitors:Cancer Suppression by Inhibitors?
Sirtuins: Selected References
Resveratrol in Transgenic Plants and other Organisms
Resveratrol: Some References of Interest and some Links to Internet Pages
Comment on  Resveratrol in the Freiburger Uni Magazin (Dec 2004)     
                                        
 

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(Last modification: 06. March 2010)     Deutsche Seiten über Resveratrol

 

Resveratrol

 

Follow the links above to more detailed pages

 

Topics in this page

  • Why could resveratrol be important for humans: More...

  • Why do not all plants contain resveratrol: More...

  • Biosynthesis of resveratrol: More...

  • What is the secret of resveratrol synthase: More...

  • Did you ever ask when Resveratrol was first discovered and described?
    I tried to find out:
    More...

  • Pinosylvin is closely related to Resveratrol: what is it and why is it interesting: More...

  • Publications from our group cited in this page: More...

 

A few other points

  • How does the University of Freiburg think about Resveratrol?
    -> Freiburger Uni-Magazin December 2004, page 30:
      
     PDF-File (65 KB, return with Browser-Back-Button)

  • It is also worthwhile to have a look at this article in the New York Times (2003):
    Nicholas Wade: Study Spurs Hope of Finding Way to Increase Human Life
    -> Return with Browser-Back Button

  • There are now many Offers for Resveratrol in the Internet: The link leads to the homepage of amazon.com:
    Use the search function on top of the page with the search term "Resveratrol".
    I give no recommendations, and please do not ask me for comments on the products or offers !

One more remark:
If you are thinking about taking resveratrol, or do it already, have a look at these pages:

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Why could resveratrol be important for humans?

 

(A more detailed discussion of resveratrol activities in context with sirtuins and extension of life span by calorie restriction is here).

 

   It has been known for a long time that a low calory diet leads in many organisms to retardation of the aging processes and to longer life. The molecular mechanisms, at least in higher organisms, are still a matter of debate. However, there are good points to be made for a hypothesis that the principles are not so fundamentally different in all organisms.
      Limiting organisms with a low calory supply activates a specific set gene of genes that leads to longer life for the individual cell, and one of the effects is that DNA repair processes operate more efficiently than in cells living in gluttony. The exciting is that this effect apparently can be mimicked by certain low molecular plant natural products, e.g. some flavonoids (e.g. quercetin) and most efficiently: resveratrol (life extension by up to 70% in yeast!). The beneficial effects of calorie restriction have been shown in all types of organisms, including rhesus monkey, i.e. mammals not too far away from Homo sapiens. Resveratrol indeed had some comparable effects in mice.  Naturally, it is not that easy to prove such beneficial effects of resveratrol, like life span extension,  with humans, but the hopes are high. Would it not be nice to counteract all the bad effects of being overweight by taking a simple pill? Without actually having to change eating habits? Is there really an easy way to a long healthy life?
      Resveratrol has only been found in plants.  However, it is not present in most of our important crops, and grapes
(Vitis vinifera) and wine are the most noticeable exceptions (more...). Actually, the presence of resveratrol in many wines (especially red wines!) may well provide the explanation for the "French paradox", i.e. that the French have less heart problems than for example North Americans, despite living on a high-fat diet and with high cholesterol levels. The explanations given for yeast may also help explaining reports that resveratrol protects against heart disease, raises the "good" HDL cholesterol, inhibits blood clots, stops viral replication, blocks cancer at every stage of development, and so on .... All these beneficial effects have been described, but it also should be noted that the conclusions are from studies with model systems. But honestly, how could it be otherwise? And who wants to wait for 125 years to prove longevity achieved by daily doses of resveratrol?
     Let's face it: All of that sounds too good to be true, one would think. Should we actually believe that taking a simple pill will counteract all those bad effects of over-eating, drinking, and smoking ? Anyway, there are many examples for offers in the Internet already; these are usually extracts from various plants, not the pure substance (would be too expensive): more...
    Anyway, the last years have brought more surprising results on the activities of resveratrol: the regulation of sirtuin activities. This turned out to be quite exciting, because supplementation with resveratrol might alleviate many of the bad consequences of eating too much, i.e. being overweight or even obese (a real problem in the Western countries): have a look at a couple of pages that I recently wrote up, on the activities of sirtuins and the effects of resveratrol in the control of major metabolic processes: more....

 

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Why do not all plants contain resveratrol?

      The answer is simple: most plants do not contain the enzyme necessary for its biosynthesis. Interestingly, a single additional enzyme is sufficient to synthesize resveratrol because the substrates are present in all plants. The first cDNAs and genes for a resveratrol synthase (from peanuts, Arachis hypogaea) were published by our group already in 1988 (Schröder et al., 1988), and thus the enzymatic basis for the biosynthesis has been known for a long time. Resveratrol is the most well-known member of a family of substances called stilbenes, and the general name for these enzymes is stilbene synthase (STS). We also described cDNAs/genes for stilbene synthases from trees containing stilbenes (but not resveratrol): Scots pine (Pinus sylvestris) (Fliegmann et al., 1992) and Eastern white pine (Pinus strobus) (Raiber et al., 1995).
      The investigations of stilbene synthase showed that the enzymes are members of a large protein family with many different roles in plant metabolism. Apart from resveratrol synthase, the most prominent member is chalcone synthase, an enzyme present in all plants. It is a key enzyme in the biosynthesis of flavonoids and anthocyanins, a large group of natural products that has also been strongly implicated in being important for human health (e.g. quercetin, see the figure below). Actually, resveratrol synthase and chalcone synthase are not only closely related (about 65-70% identical!), but both use the same substrates, and the reactions are very similar (for the interested: a comparison of the biosynthesis is shown below). There is good evidence that resveratrol synthase developed from chalcone synthase several times in evolution (Tropf et al., 1994), via processes well-known: gene duplication and mutation to new and improved functions.
      Note: there are now many transgenic plants synthesizing resveratrol: More..., and thus there are, at least in theory, many interesting ways to get your resveratrol!

 

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The enzyme reactions: Biosynthesis of resveratrol, chalcone, and quercetin

            Both biosynthetic activities require 4-coumaroyl-CoA and three malonyl-CoA; these are present in all plants. The chalcone is the precursor for the ubiquitous flavonoids and anthocyanins. The reactions of resveratrol synthase and chalcone synthase are very similar, and only the final ring-folding is different in resveratrol synthase. Quercetin (a flavonol derived from chalcone) is shown here because it has been much discussed as beneficial flavonoid.
      Resveratrol synthase and chalcone synthase are condensing enzymes; they use three sequential condensation reactions with malonyl-CoA to  produce an enzyme-bound tetraketide  intermediate. Up to that stage the reactions of the two enzymes are identical. The difference is in what happens afterwards, in the formation of the final product: the ring-folding is different.  The color-coding of the products tells you where the carbon atoms in the final products came from.

 

Synthesis of resveratrol and chalcone (the precursor of quercetin).
The key enzymes are  stilbene synthase (STS) and chalcone synthase (CHS). Both use 4-coumaroyl-CoA and perform three condensation reactions with malonyl-CoA; the colours mark the three condensation reactions. The resulting linear tetraketide is folded into new ring systems, and that is the important difference between the two enzymes. Apart from that, it is a special property of STS that it looses the terminal carboxyl group as CO2.

Both resveratrol and quercetin are important activators of the human sirtuin SIRT1: more...

Biosynthesis of Resveratrol, Quercetin, and Chalcone

Nomenclature and numbering: chalcone and quercetin, resveratrol

 

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What is the secret of resveratrol synthase?

      Why do chalcone synthases make chalcones, but resveratrol synthases resveratrol? This has been puzzling since the discovery of resveratrol synthase. Now, finally, the crystal structure of a stilbene synthase provides an answer: it is a novel molecular switch that decides whether a protein makes a stilbene or a chalcone. With this information it was possible to change a chalcone synthase into a resveratrol synthase by mutagenesis of a few key amino acids, and it was also possible to obtain enzymes which can make both resveratrol and chalcone. The publication appeared in the 2004 September issue of the Journal "Chemistry & Biology", and a look at it is very worthwhile. How about putting that gene into other crop plants? Many have thought about that previously, but mostly in the context in providing plants with the capacity to synthesize new phytoalexins (that was previously the property of resveratrol considered most important). The new aspects will very likely kindle the interest to much higher levels: how about  getting your resveratrol with your breakfast cereal or bread, or fruit? Sounds good, doesn't it? No expensive pills! As mentioned above, there are already a quite large number of transgenic plants that synthesize resveratrol: more...

 

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Do you want to know more about this protein family?

  • go to: type III polyketide synthases: more...,
        - overview of proteins related to resveratrol (stilbene) synthase and chalcone synthase

  • or go directly to chalcone synthase (more...) or resveratrol/stilbene synthase (more...)

  • or go directly to: Schröder group publications on the family of chalcone synthase related proteins: more...

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Discovery of resveratrol

    Sooner or later you start to wonder when resveratrol was actually discovered and first described. Many websites think that this was in 1963, from the plant Polygonum cuspidatum  (= Fallopia japonica = Reynoutria japonica; Japanese knotweed, Japanischer Staudenknöterich). Interestingly, this plant is now considered as invasive pest in many Western countries, but it is also today one of the major sources of resveratrol preparations (and seemingly the cheapest!). From what I could find out, the publication is most likely this: Nonomura et al. (1963). Most websites do not give the details of the citation: not too surprising because it is not easily accessible and moreover in Japanese; it seems pretty doubtful whether it was actually read by many people in the Western countries.
     Even a brief literature search shows that this was not the first report of resveratrol: it was described already several years earlier from Eucalyptus wandoo, a Eucalypt tree native to Western Australia (Hathway and Seakins, 1959). The English name is '
Powder-barked Wandoo', and the latin name now seems to be Eucalyptus accedens. The reference list in that article indicated that there are earlier reports of resveratrol, but again in Japanese journals. It is not easy to obtain these very early Japanese publications, and also many of us have problems with reading and understanding Japanese. Therefore I asked a friendly colleague at the University of Tokyo, Prof. Yutaka Ebizuka for assistance, and I am really grateful for his help. The earliest publication discovered by him is actually from 1939It describes the identification of resveratrol in Veratrum grandiflorum (Takaoka, 1939). The taxonomy again appears a bit complicated: 'Veratrum grandiflorum (Maxim. ex Baker) Loes.' is the synonym to '
Veratrum album L. var. grandiflorum Maxim. ex Baker', i.e. it is now considered as a variety of Veratrum album (White Hellebore = False Helleborine; Weisser Germer = Nieswurz).

     He also sent me a scan of the publication: it is in Japanese (I can send the scan to you, if you want), and he was so nice to summarize the content for me  in English (his text is added to the reference). It is simply amazing with which simple but effective techniques the researchers at that time produced such excellent results! So, this seems to be the first description of resveratrol: please let me know if you are aware of even older publications!

    Another question that I am often asked: what is the origin of the name 'resveratrol'? The publication from 1939 gives no explanation, but, as suggested by the Japanese colleague, the type of molecule and the name of the plant make it easy to think of the following:

  • res: might be an abbreviation of the class of molecules: resveratrol belongs to the resorcinols,

  • veratr: abbreviation of the plant name, Veratrum,

  • ol: is generally used for indicating hydroxyl groups: resveratrol has three of them. 

Please let me know if you have better information or ideas !

 

Pinosylvin, an interesting stilbene closely related to resveratrol

    Pinosylvin is a stilbene closely related to resveratrol: just replace the 4-coumaroyl-CoA in the biosynthetic scheme above by cinnamoyl-CoA , and carry out the standard stilbene synthase reaction. Cinnamoyl-CoA is simply 4-coumaroyl-CoA without the hydroxyl group (-OH) at the aromatic ring system. This stilbene also has interesting medical potential, but not so much work focussed on it. The name pinosylvin is derived from the plant from which it was described first: Scots pine, Pinus sylvestris. (Erdtman, 1939a, 1939b; note that this was in the same year that resveratrol was first described!). Its early discovery is actually quite interesting, and the research had a solid economical basis: it was the search for compounds in the heartwood of Scots pine (Pinus sylvestris) which inhibited the standard wood pulping procedure with sulfite, and pinosylvin incorporated into the heartwood certainly had an important part in that (Erdtman 1939b)!  Of course the biosynthetic enzyme, the pinosylvin synthase, was also interesting for us, and we cloned these stilbene synthases from two trees: Scots pine (Pinus sylvestris) (Fliegmann et al., 1992, Schanz et al., 1992) and Eastern White Pine (Pinus strobus)  (Raiber et al., 1995)

 

 References for discovery of Resveratrol and Pinosylvin

  • Erdtman, H., 1939a. Zur Kenntnis der Extraktivstoffe des Kiefernkernholzes. Naturwissenschaften 27, 130-131.
    No Abstract.
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  • Erdtman, H., 1939b. Die phenolischen Inhaltsstoffe des Kiefernkernholzes, ihre physiologische Bedeutung und hemmende Einwirkung auf die normale Aufschließbarkeit des Kiefernkernholzes nach dem Sulfitverfahren. Justus Liebig's Annalen der Chemie 539, 116-127.
    No Abstract.
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  • Hathway, D. E., Seakins, J. W. T., 1959. Hydroxystilbenes of Eucalyptus wandoo. Biochemical Journal 72, 369-374.
    1. Two hydroxystilbenes have been isolated from the ether-soluble extractives of Eucalyptus wandoo heartwood by cellulose- and polyamide- column chromatography.
    2. One of the hydroxystilbenes has been identified as 3:5:4'-trihydroxystilbene (= Resveratrol) and the other as 3:5:4'-trihydroxystilbene-3-ß-D-glucoside.
    3. In E. warndoo heartwood, the 3:5:4'-trihydroxystilbenes are laid down within ether-insoluble membrane substances.
    4. The translocation, function and ontogenesis of the 3:5:4'-trihydroxystilbenes is discussed.
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  • Nonomura, S., Kanagawa, H., Makimoto, A., 1963. [Chemical constituents of polygonaceous plants. I. Studies on the components of Ko-Jo-Kon. (Polygonum cuspidatum Sieb. et Zucc.)] (Translation of Japanese Title). Yakugaku Zasshi (= Journal of the Pharmaceutical Society of Japan) 83, 988-990.
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  • Takaoka, M., 1939. [Resveratrol, a new phenolic compound, from Veratrum grandiflorum] (Translation of Japanese Title). Nippon Kagaku Kaishi (= Journal of the Chemical Society of Japan) 60, 1090-1100.
    The English summary, established by Prof. Ebizuka:
    He isolated a phenolic compound, by crystallization alone!!, from an ether soluble and non-basic fraction of EtOH extracts of Veratrum grandiflorum Loes. fil. collected in Hokkaido Island. Molecular formula was obtained by elemental analysis of itself, its triacetate and trimethylether. CrO3 oxidation of trimethylether in AcOH at room temperature afforded 3,5-dimethoxybenzaldehyde, while in boiling AcOH produced p-anisic acid. These degradation products were identified by direct comparison with authentic specimens. Some additional information including color reactions and comparison of UV spectrum with some stilbene derivatives led him to conclude its structure.
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Publications from our group cited in this page

 

Title page from Chemistry & Biology, 2004: an artist's view of resveratrol synthase and resveratrol in red wine
Title page from Chemistry & Biology, 2004
  • Austin,M.B.; Bowman,M.E.; Ferrer,J.-L.; Schröder,J.; Noel,J.P.: An aldol switch discovered in stilbene synthases mediates cyclization specificity of type III polyketide synthases. Chemistry & Biology 11, 1179-1194 (2004)
       Stilbene synthase (STS) and chalcone synthase (CHS) each catalyze the formation of a tetraketide intermediate from a CoA-tethered phenylpropanoid starter and three molecules of malonyl-CoA, but use different cyclization mechanisms to produce distinct chemical scaffolds for a variety of plant natural products. Here we present the first STS crystal structure, and identify, by mutagenic conversion of alfalfa CHS into a functional stilbene synthase, the structural basis for the evolution of STS cyclization specificity in type III polyketide synthase (PKS) enzymes. Additional mutagenesis and enzymatic characterization confirms that electronic effects rather than steric factors balance competing cyclization specificities in CHS and STS. Finally, we discuss the problematic in vitro reconstitution of plant stilbenecarboxylate pathways, using insights from existing biomimetic polyketide cyclization studies to generate a novel mechanistic hypothesis to explain stilbenecarboxylate biosynthesis.
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  • Schröder, G., Brown, J.W.S. and Schröder, J.: Molecular analysis of resveratrol synthase: cDNA, genomic clones and relationship with chalcone synthase. European Journal of Biochemistry 172, 161-169 (1988).
        Resveratrol synthase (RS), a key enzyme in biosynthesis of stilbene-type phytoalexins, catalyzes the formation of resveratrol from coumaroyl-CoA and malonyl-CoA. Two cDNA clones, pGSC1 and pGSC2, have been isolated from cDNA libraries established with poly(A)-rich RNA from peanut (Arachis hypogaea) cell cultures specifically induced for RS. These cDNAs were used to identify two genomic clones (pGSG10 and pGSG11). Sequence analysis shows that the two clones overlap in a large stretch of nearly identical sequences, and that pGSG10 contains the 5' and pGSG11 the 3' end of RS genes. The sequences reveal a single intron, and the size of the predicted protein is 42.7 kDa, in close agreement with that observed in polyacrylamide gels (43 kDa). Chalcone synthase (CHS), a key enzyme of flavonoid biosynthesis, utilizes the same substrates as RS, but the product is different (naringenin chalcone). Comparison of RS with CHS consensus sequences shows that the two genes are related. Homology extends throughout the coding region, and the intron in RS is at the same position as a conserved intron in CHS. However, RS reveals a substantial number of amino acid differences to CHS in positions highly conserved in all CHS enzymes. It is proposed that the two proteins possess a commmon scaffold necessary for binding of the substrates and the type of enzyme reaction, and that the differences are responsible for the formation of different products.
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    Return to text or go to some  pictures

  • Fliegmann, J., Schröder, G., Schanz, S., Britsch, L. and Schröder, J.: Molecular analysis of chalcone and dihydropinosylvin synthase from Scots pine (Pinus sylvestris), and differential regulation of these and related enzyme activities in stressed plants. Plant Molecular Biology 18, 489-503 (1992).
        Chalcone synthase (CHS) and stilbene synthase (STS) are closely related polyketide synthases which are key enzymes in the biosynthesis of flavonoids and stilbenes. Scots pine (Pinus sylvestris) is an interesting plant for a direct comparison of the enzymes. It not only contains the usual flavonoids, but also an unusual chalcone derivative (pinocembrin), and it synthesizes stilbenes of the pinosylvin type. We analysed a CHS and a STS by molecular cloning and functional expression in Escherichia coli. The CHS was active not only with 4-coumaroyl-CoA (to naringenin chalcone), but also with cinnamoyl-CoA (leading to pinocembrin). The STS was identified as dihydropinosylvin synthase, because it preferred dihydrocinnamoyl-CoA to cinnamoyl-CoA. The protein deviated in 47 positions from the CHS consensus. It had 73.2% identity with the CHS from P. sylvestris and only 65.3% with a STS from peanut (Arachis hypogaea). We also investigated the regulation of both enzyme types in P. sylvestris plantlets exposed to stress. CHS was present in non-stressed plantlets, and induction led to a transient increase with a peak after 16 h. STS1 type activities were regulated differently and were absent in non-stressed plantlets. Increases were observed after a lag period of at least 6 h, and highest activities were obtained after 30 h. The analysis of the reactions in the plant extracts and the substrate specificity of the cloned STS suggest that the plants contain at least two different types of STS: the cloned dihydropinosylvin synthase and a pinosylvin synthase which preferentially utilizes cinnamoyl-CoA as substrate.
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    Return to text or Pinosylvin or go to some pictures

  • Schanz, S., Schröder, G. and Schröder, J.: Stilbene synthase from Scots pine (Pinus sylvestris). FEBS Letters 313, 71-74 (1992).
        Stilbene synthases are named according to their substrate preferences. By this definition, enzymes preferring cinnamoyl-CoA are pinosylvin synthases, and proteins with a preference for phenylpropionyl-CoA are dihydropinosylvin synthases. We investigated the assignment of a stilbene synthase cloned from Scots pine (Pinus sylvestris) as dihydropinosylvin synthase and the proposal of an additional pinosylvin synthase (1992, Plant Mol. Biol. 18, 489-503). The results show that the previous interpretation was misled by several unexpected factors. Firstly, we found that the substrate preference and the activity of the plant-specific protein expressed in Escherichia coli was influenced by bacterial factors. This was reduced by improvement of the expression system, and the subsequent kinetic analysis revealed that cinnamoyl-CoA rather than phenylpropionyl-CoA is the preferred substrate of the cloned stilbene synthase. Secondly, mixing experiments showed that extracts from P. sylvestris contain factor(s) which selectively influenced the substrate preference, i.e. the activity was reduced with phenylpropionyl- CoA, but not with cinnamoyl-CoA. This explained the apparent differences between plant extracts and the cloned enzyme expressed in E. coli. Taken together, the results indicate that the cloned enzyme is a pinosylvin synthase, and there is no evidence for a second stilbene synthase. This study cautions that factors in the natural and in new hosts may complicate the functional identification of cloned sequences.
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    Pinosylvin
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  • 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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    Return to text or Pinosylvin or go to a picture

  • Tropf, S., Lanz, T., Rensing, S.A., Schröder, J. and Schröder, G.: Evidence that stilbene synthases have developed from chalcone synthases several times in the course of evolution. Journal of Molecular Evolution 38, 610-618 (1994).
        Chalcone (CHS) and stilbene (STS) synthases are related plant- specific polyketide synthases that are key enzymes in the biosynthesis of flavonoids and of stilbene phytoalexins, respectively. A phylogenetic tree constructed from 34 CHS and four STS sequences revealed that the STS formed no separate cluster but grouped with CHS from the same or related plants. This suggested that STS evolved from CHS several times independently. We attempted to simulate this by site-directed mutagenesis of an interfamily CHS/STS hybrid, which contained 107 amino acids of a CHS from Sinapis alba (N-terminal) and 287 amino acids of a STS from Arachis hypogaea. The hybrid had no enzyme activity. Three amino acid exchanges in the CHS part (Gln-100 to Glu, Val-103 to Met, Val-105 to Arg) were sufficient to obtain low STS activity, and one additional exchange (Gly-23 to Thr) resulted in 20-25% of the parent STS activity. A kinetic analysis indicated (1) that the hybrids had the same Km for the substrate 4-coumaroyl-CoA but a lower Vmax than the parent STS, and (2) that they had a different substrate preference than the parent STS and CHS. Most of the other mutations and their combinations led to enzymatically inactive protein aggregates, suggesting that the subunit folding and/or the dimerization was disturbed. We propose that STS evolved from CHS by a limited number of amino acid exchanges, and that the advantage gained by this enzyme function favored the selection of plants with improved STS activity.  
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