TY - JOUR
T1 - Participation and properties of lipoxygenase and hydroperoxide lyase in volatile C6-aldehyde formation from C18-unsaturated. Fatty acids in isolated tea chloroplasts
AU - Hatanaka, Akikazu
AU - Kajiwara, Tadahiko
AU - Sekiya, Jiro
AU - Imoto, Masaya
AU - Inouye, Satoshi
PY - 1982/1
Y1 - 1982/1
N2 - Isolated tea chloroplasts utilized linoleic acid, linolenic acid and their 13-hydroperoxides as substrates for volatile C6-aldehyde formation. Optimal pH values for oxygen uptake, hydroperoxide lyase and the overall reaction from C18-fatty acids to C6-aldehydes were 6.3, 7.0 and 6.3, respectively. Methyl linoleate, linoleyl alcohol and γ-linolenic acid were poor substrates for the overall reaction, but linoleic and linolenic acids were good substrates. The 13-hydroperoxides of the above fatty acids and alcohol also showed substrate specificity similar to that of fatty acids. Oxygen uptakes (relative Vmax) with methyl linoleate, linoleyl alcohol, linolenic acid, γ-linolenic acid and arachidonic acid were comparable to or higher than that with linoleic acid. In winter leaves, the activity for C6-aldehyde formation from C18-fatty acids was raduced to almost zero. This was due to the reduction in oxygenation. The findings presented here provide evidence for the involvement of lipoxygenase and hydroperoxide lyase in C6-aldehyde formation in isolated chloroplasts.
AB - Isolated tea chloroplasts utilized linoleic acid, linolenic acid and their 13-hydroperoxides as substrates for volatile C6-aldehyde formation. Optimal pH values for oxygen uptake, hydroperoxide lyase and the overall reaction from C18-fatty acids to C6-aldehydes were 6.3, 7.0 and 6.3, respectively. Methyl linoleate, linoleyl alcohol and γ-linolenic acid were poor substrates for the overall reaction, but linoleic and linolenic acids were good substrates. The 13-hydroperoxides of the above fatty acids and alcohol also showed substrate specificity similar to that of fatty acids. Oxygen uptakes (relative Vmax) with methyl linoleate, linoleyl alcohol, linolenic acid, γ-linolenic acid and arachidonic acid were comparable to or higher than that with linoleic acid. In winter leaves, the activity for C6-aldehyde formation from C18-fatty acids was raduced to almost zero. This was due to the reduction in oxygenation. The findings presented here provide evidence for the involvement of lipoxygenase and hydroperoxide lyase in C6-aldehyde formation in isolated chloroplasts.
KW - Chloroplasts (tea)
KW - Fatty acid hydroperoxides
KW - Hexanal and hexenal formation
KW - Hydroperoxide lyase
KW - Lipoxygenase
KW - Thea sinensis
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U2 - 10.1093/oxfordjournals.pcp.a076334
DO - 10.1093/oxfordjournals.pcp.a076334
M3 - Article
AN - SCOPUS:0013666559
VL - 23
SP - 91
EP - 99
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
SN - 0032-0781
IS - 1
ER -