Induction of 4-hydroxycinnamate decarboxylase in Klebsiella oxytoca cells exposed to substrates and non-substrate 4-hydroxycinnamate analogs.
The 4-hydroxycinnamate decarboxylase (4-HCD)-inducing activity of several substrate analogs toward Klebsiella oxytoca was investigated. Four E-cinnamate-class compounds, E-4-hydroxycinnamic acid (1), caffeic acid (2), ferulic acid (3) and E-2,4-dihydroxycinnamic acid (4), all of which were accepted as substrates, all of which were accepted as substrates of 4-HCD, enable K. oxytoca cells to induce the decarboxylase at a 2.0 mM concentration, while five non-substrate compounds of the E-cinnamate class so far tested were completely inactive. However, 6-hydroxy-2-naphthoic acid (11) and 7-hydroxycoumarin 3-carboxylic acid (14), both of which are non-cinnamate-class analogs of the substrate, acted as strong 4-HCD inducers, even at a 0.5 mM concentration. The 4-HCD-inducing activities of compounds 11 and 14 at 0.5 mM were 10-12-fold higher than that of substrate 1. Compound 11 maintained its 4-HCD-inducing activity toward cultured cells through the late-log and stationary phases, unlike 1 that induced 4-HCD only in the early log phase. SDS-PAGE electrophoresis of protein mixtures from the cultured cells exposed to any 4-HCD inducer indicated that the 21.5 kDa protein was always present.
Hashidoko
Y
Y
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan. yasu-h@abs.agr.hokudai.ac.jp
Tanaka
T
T
Tahara
S
S
D002262:Carboxy-Lyases / Q000096:biosynthesis* / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism*; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D007709:Klebsiella / Q000166:cytology / Q000201:enzymology*; D011422:Propionates; D013379:Substrate Specificity
D003373:Coumaric Acids; D003470:Culture Media; D011422:Propionates; C460086:4-hydroxycinnamate decarboxylase; D002262:Carboxy-Lyases; C495469:p-coumaric acid