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3404381 
Journal Article 
Characterization of an isoprene synthase from leaves of Quercus petraea (Mattuschka) Liebl 
Schnitzler, JP; Arenz, R; Steinbrecher, R; Lehning, A 
1996 
0 
Botanica Acta
ISSN: 0932-8629 
109 
3 
216-221 
English 
WOS:A1996UY38900008 
Biogenic emission of isoprene (2‐methyl‐1,3‐butadiene) by many plant species plays an important role in atmospheric chemistry. Its rapid breakdown in the atmosphere substantially affects the oxidation potential of the atmosphere. Leaves of Quercus petraea were found to contain an enzyme which catalyses the conversion of dimethylallyl pyrophosphate (DMAPP) to isoprene. A standard enzyme assay was established and the isoprene synthase activity was characterized in purified leaf extracts. Optimum enzyme activity was observed at pH 8.5. The enzyme had an apparent Km of 0.97 mM for its substrate DMAPP, but isopentenyl pyrophosphate (IPP), the isomeric form of DMAPP, was not converted to isoprene by the enzyme extract. The temperature optimum of the enzyme activity was 35 °C. Isoprene synthase activity was strictly dependent on the presence of bivalent cations, with magnesium being most effective. Molecular weight determination by FPLC revealed the presence of a single protein with a native molecular weight of approximately 90–100 kDa. 
isoprene synthase; characterization; Quercus petraea leaves