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Characterisation of acyl-ACP desaturases from Macadamia integrifolia Maiden & Betche and Nerium oleander L.

Gummeson, PO; Lenman, Marit LU ; Lee, M; Singh, S and Stymne, S (2000) In Plant Science 154(1). p.53-60
Abstract
The seed oil in Macadamia integrifolia contains about 30% palmitoleic acid (16:1(Delta9)) and Nerium oleander about 12% isoricinoleic acid (Delta9-hydroxy-18:1(Delta12)). It has been shown that palmitoleic acid can be produced by acyl-acyl carrier protein (ACP) desaturases and it has also been shown that fatty acid hydroxylation can occur via direct substitution of a hydrogen atom. Therefore it seemed possible that the enzymes responsible for the making of these unusual fatty acids in M. integrifolia and N. oleander were of acyl-ACP desaturase type. Extracts from developing M. integrifolia developing seeds showed a relative ratio of 16:0-ACP to 18:0-ACP desaturation that was about 13 times higher than in sunflower seeds. N. oleander seed... (More)
The seed oil in Macadamia integrifolia contains about 30% palmitoleic acid (16:1(Delta9)) and Nerium oleander about 12% isoricinoleic acid (Delta9-hydroxy-18:1(Delta12)). It has been shown that palmitoleic acid can be produced by acyl-acyl carrier protein (ACP) desaturases and it has also been shown that fatty acid hydroxylation can occur via direct substitution of a hydrogen atom. Therefore it seemed possible that the enzymes responsible for the making of these unusual fatty acids in M. integrifolia and N. oleander were of acyl-ACP desaturase type. Extracts from developing M. integrifolia developing seeds showed a relative ratio of 16:0-ACP to 18:0-ACP desaturation that was about 13 times higher than in sunflower seeds. N. oleander seed extracts catalysed conversion of 18:0-ACP to 18:1(Delta9) but only trace amounts of Delta9-hydroxy fatty acids were formed. A total of four cDNAs were isolated from developing seeds, of both species, using a fragment isolated with PCR amplification. The M. integrifolia acyl-ACP desaturase cDNA was expressed in Escherichia coli. A partly purified fraction of the enzyme showed a 16:0-ACP to 18:0-ACP desaturation ratio about 90-fold less than that in the Macadamia extracts. Expressed N. oleander acyl-ACP desaturase cDNAs showed predominantly 18:0-ACP desaturase activity and no hydroxylase activity. Thus it is not likely that any of the four acyl-ACP desaturases cloned from M. integrifolia or N. oleander is involved in the production of unusual fatty acids. (Less)
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author
publishing date
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Contribution to journal
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published
subject
keywords
Macadamia integrifolia, Acyl-ACP desaturase, Nerium oleander
in
Plant Science
volume
154
issue
1
pages
53 - 60
publisher
Elsevier
ISSN
0168-9452
language
English
LU publication?
no
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58712c34-d4e9-4633-85a1-e509c136ed63 (old id 1209911)
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http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TBH-3YTJCPX-6-5&_cdi=5143&_user=745831&_orig=browse&_coverDate=05%2F15%2F2000&_sk=998459998&view=c&wchp=dGLbVzz-zSkzk&md5=c850997313adfee883744034a3b2de49&ie=/sdarticle.pdf
date added to LUP
2008-08-25 14:24:19
date last changed
2016-06-29 09:16:34
@article{58712c34-d4e9-4633-85a1-e509c136ed63,
  abstract     = {The seed oil in Macadamia integrifolia contains about 30% palmitoleic acid (16:1(Delta9)) and Nerium oleander about 12% isoricinoleic acid (Delta9-hydroxy-18:1(Delta12)). It has been shown that palmitoleic acid can be produced by acyl-acyl carrier protein (ACP) desaturases and it has also been shown that fatty acid hydroxylation can occur via direct substitution of a hydrogen atom. Therefore it seemed possible that the enzymes responsible for the making of these unusual fatty acids in M. integrifolia and N. oleander were of acyl-ACP desaturase type. Extracts from developing M. integrifolia developing seeds showed a relative ratio of 16:0-ACP to 18:0-ACP desaturation that was about 13 times higher than in sunflower seeds. N. oleander seed extracts catalysed conversion of 18:0-ACP to 18:1(Delta9) but only trace amounts of Delta9-hydroxy fatty acids were formed. A total of four cDNAs were isolated from developing seeds, of both species, using a fragment isolated with PCR amplification. The M. integrifolia acyl-ACP desaturase cDNA was expressed in Escherichia coli. A partly purified fraction of the enzyme showed a 16:0-ACP to 18:0-ACP desaturation ratio about 90-fold less than that in the Macadamia extracts. Expressed N. oleander acyl-ACP desaturase cDNAs showed predominantly 18:0-ACP desaturase activity and no hydroxylase activity. Thus it is not likely that any of the four acyl-ACP desaturases cloned from M. integrifolia or N. oleander is involved in the production of unusual fatty acids.},
  author       = {Gummeson, PO and Lenman, Marit and Lee, M and Singh, S and Stymne, S},
  issn         = {0168-9452},
  keyword      = {Macadamia integrifolia,Acyl-ACP desaturase,Nerium oleander},
  language     = {eng},
  number       = {1},
  pages        = {53--60},
  publisher    = {Elsevier},
  series       = {Plant Science},
  title        = {Characterisation of acyl-ACP desaturases from Macadamia integrifolia Maiden & Betche and Nerium oleander L.},
  volume       = {154},
  year         = {2000},
}