Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed

Edgar B. Cahoon; Sean J. Coughlan; John Shanklin

doi:10.1023/A:1005821007291

Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed

Edgar B. Cahoon, Sean J. Coughlan, John Shanklin

Research output: Contribution to journal › Article › peer-review

35 Scopus citations

Abstract

A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1Δ⁹)* and cis-vaccenic (18:1Δ¹¹) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed Δ⁹ desaturation of acyl-ACP substances, and the recombinant enzyme exhibited seven-to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known Δ⁹-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized Δ⁹-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a Δ⁹-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

Original language	English (US)
Pages (from-to)	1105-1110
Number of pages	6
Journal	Plant Molecular Biology
Volume	33
Issue number	6
DOIs	https://doi.org/10.1023/A:1005821007291
State	Published - Apr 1997
Externally published	Yes

Keywords

Asclepias syriaca
fatty acid desaturase

ASJC Scopus subject areas

Agronomy and Crop Science
Genetics
Plant Science

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10.1023/A:1005821007291

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title = "Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed",

abstract = "A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1Δ9)* and cis-vaccenic (18:1Δ11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed Δ9 desaturation of acyl-ACP substances, and the recombinant enzyme exhibited seven-to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known Δ9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized Δ9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a Δ9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.",

keywords = "Asclepias syriaca, fatty acid desaturase",

author = "Cahoon, {Edgar B.} and Coughlan, {Sean J.} and John Shanklin",

note = "Funding Information: We thank Dr John Ohlrogge (Michigan State University) for supplying [1-14C]10:0-ACP. We also thank Rebecca Peck for critical reading of the manuscript. This research was supported by the Office of Basic Energy Sciences of the U.S. Department of Energy and Brookhaven National Laboratory Directed Research and Development Program No 94-31.",

year = "1997",

month = apr,

doi = "10.1023/A:1005821007291",

language = "English (US)",

volume = "33",

pages = "1105--1110",

journal = "Plant Molecular Biology",

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publisher = "Springer Science and Business Media B.V.",

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T1 - Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed

AU - Cahoon, Edgar B.

AU - Coughlan, Sean J.

AU - Shanklin, John

N1 - Funding Information: We thank Dr John Ohlrogge (Michigan State University) for supplying [1-14C]10:0-ACP. We also thank Rebecca Peck for critical reading of the manuscript. This research was supported by the Office of Basic Energy Sciences of the U.S. Department of Energy and Brookhaven National Laboratory Directed Research and Development Program No 94-31.

PY - 1997/4

Y1 - 1997/4

N2 - A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1Δ9)* and cis-vaccenic (18:1Δ11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed Δ9 desaturation of acyl-ACP substances, and the recombinant enzyme exhibited seven-to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known Δ9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized Δ9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a Δ9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

AB - A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1Δ9)* and cis-vaccenic (18:1Δ11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed Δ9 desaturation of acyl-ACP substances, and the recombinant enzyme exhibited seven-to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known Δ9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized Δ9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a Δ9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

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KW - fatty acid desaturase

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Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed

Abstract

Keywords

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