Literature DB >> 24257852

N-methyltransferase activities in suspension cultures of Coffea arabica L.

T W Baumann1, R Koetz, P Morath.   

Abstract

Suspension cultures of Coffea arabica L. are a useful source for methyltransferase preparations of high activity catalysing the transfer of methylgroups from S-adenosyl-L-methionine to 7-methylxanthine and to theobromine producing theobromine and caffeine respectively. Surprisingly, these enzyme activities are not correlated with the availability of precursors during a culture cycle. They are highest in the growth phase when supply of precursors is reduced. Mixed substrate experiments and time dependent changes in the enzyme activity ratio provide indirect evidence for the existence of two separate enzymes catalysing the final methylations in caffeine biosynthesis.

Entities:  

Year:  1983        PMID: 24257852     DOI: 10.1007/BF00269231

Source DB:  PubMed          Journal:  Plant Cell Rep        ISSN: 0721-7714            Impact factor:   4.570


  4 in total

1.  Graphical determination of the dissociation constants for two-substrate enzyme systems.

Authors:  J R FLORINI; C S VESTLING
Journal:  Biochim Biophys Acta       Date:  1957-09

2.  A rapid, sensitive, and specific method for the determination of protein in dilute solution.

Authors:  W Schaffner; C Weissmann
Journal:  Anal Biochem       Date:  1973-12       Impact factor: 3.365

3.  Biosynthesis of caffeine by tea-leaf extracts. Enzymic formation of theobromine from 7-methylxanthine and of caffeine from theobromine.

Authors:  T Suzuki; E Takahashi
Journal:  Biochem J       Date:  1975-01       Impact factor: 3.857

4.  [Caffeine synthesis in fruits and tissue cultures of Coffea arabica].

Authors:  H Keller; H Wanner; T W Baumann
Journal:  Planta       Date:  1972-12       Impact factor: 4.116

  4 in total
  2 in total

1.  Purification and characterization of caffeine synthase from tea leaves.

Authors:  M Kato; K Mizuno; T Fujimura; M Iwama; M Irie; A Crozier; H Ashihara
Journal:  Plant Physiol       Date:  1999-06       Impact factor: 8.340

2.  Molecular cloning and functional characterization of three distinct N-methyltransferases involved in the caffeine biosynthetic pathway in coffee plants.

Authors:  Hirotaka Uefuji; Shinjiro Ogita; Yube Yamaguchi; Nozomu Koizumi; Hiroshi Sano
Journal:  Plant Physiol       Date:  2003-05       Impact factor: 8.340

  2 in total

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