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

Biochemistry and Cell Biology

Brookhaven National Laboratory
Pioneer Hi-Bred International, Inc.

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
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

Keywords

Asclepias syriaca
fatty acid desaturase

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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",

year = "1997",

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doi = "10.1023/A:1005821007291",

language = "English",

volume = "33",

pages = "1105--1110",

journal = "Plant Molecular Biology",

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TY - JOUR

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

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.

KW - Asclepias syriaca

KW - fatty acid desaturase

UR - https://www.scopus.com/pages/publications/0031128388

U2 - 10.1023/A:1005821007291

DO - 10.1023/A:1005821007291

M3 - Article

C2 - 9154992

AN - SCOPUS:0031128388

SN - 0167-4412

VL - 33

SP - 1105

EP - 1110

JO - Plant Molecular Biology

JF - Plant Molecular Biology

IS - 6

ER -

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

Abstract

Keywords

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