delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

Cahoon, Edgar B.; Cranmer, Ann M.; Shanklin, John; Ohlrogge, John B.

doi:10.1016/s0021-9258(18)47015-9

Cited by 77 publications

(10 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…EVolutionary Consequences of Acyl Chain SelectiVity. A number of variant acyl-ACP desaturases with selectivities for shorter chain acyl-ACPs and with specificities for doublebond insertion at different positions have recently been identified (11,(55)(56)(57)(58)(59). These enzymes are undoubtedly evolved from an ancestral acyl-ACP desaturase gene, on the basis of the high amino acid sequence identity.…”

Section: Resultsmentioning

confidence: 99%

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ⁹ Desaturase

Haas

Fox

1999

Biochemistry

View full text Add to dashboard Cite

Stearoyl acyl carrier protein Delta(9) desaturase (Delta9D) uses a diiron center to catalyze the NADPH- and O(2)-dependent desaturation of stearoyl acyl carrier protein (ACP) to form oleoyl-ACP. The reaction of recombinant Ricinus communis Delta9D with natural and nonnatural chain length acyl-ACPs was used to examine the coupling of the reconstituted enzyme complex, the specificity for position of double-bond insertion, the kinetic parameters for the desaturation reaction, and the selectivity for acyl chain length. The coupling of NADPH and O(2) consumption and olefin production was found to be maximal for 18:0-ACP, and the loss of coupling observed for the more slowly desaturated acyl-ACPs was attributed to autoxidation of the electron-transfer chain. Analysis of steady-state kinetic parameters for desaturation of acyl-ACPs having various acyl chain lengths revealed that the K(M) values were similar ( approximately 2.5-fold difference) for 15:0-18:0-ACP, while the k(cat) values increased by approximately 26-fold for the same range of acyl chain lengths. A linear increase in log (k(cat)/K(M)) was observed upon lengthening of the acyl chain from 15:0- to 18:0-ACP, while no further increase was observed for 19:0-ACP. The similarity of the k(cat)/K(M) values for 18:0- and 19:0-ACPs and the retained preference for double-bond insertion at the Delta(9) position with 19:0-ACP (>98% desaturation at the Delta(9) position) suggest that the active-site channel past the diiron center can accommodate at least one more methylene group than is found in the natural substrate. The DeltaDeltaG(binding) estimated from the change in k(cat)/K(M) for increasing substrate acyl-chain length was -3 kJ/mol per methylene group, similar to the value of -3.5 kJ/mol estimated for the hydrophobic partition of long-chain fatty acids (C-7 to C-21) from water to heptane [Smith, R. , and Tanford, C. (1973) Proc. Natl. Acad. Sci. U.S.A. 70, 289-293]. Since the K(M) values are overall similar for all acyl-ACPs tested, the progressive increase in hydrophobic binding energy available from increased chain length is apparently utilized to enhance catalytic steps, which thus provides the underlying physical mechanism for acyl chain selectivity observed with Delta9D.

show abstract

Section: Resultsmentioning

confidence: 99%

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ⁹ Desaturase

Haas

Fox

1999

Biochemistry

View full text Add to dashboard Cite

show abstract

“…The desaturation and oxygenation activity of Δ 9 Ds was assessed by incubating a particular enzyme (10 μM) in a 200 μL reaction mixture containing 0.15 M NaCl, 25 mM KH 2 PO 4 , pH 7.5, 4 μM Fd, 0.2 U.mL −1 FdR, 2 mM NADPH, 0.5 mM acyl-CoA, 1000 U.mL −1 CAT, 0.5 mM Triton X-100 and 10 g.L −1 glycerol [38] , [39] , [40] . The reaction was carried out in an open vial (1.5 mL) placed into a water bath at 35 °C for 4 h, and the mixture was subsequently lyophilized overnight to remove excess water.…”

Section: Methodsmentioning

confidence: 99%

Understanding desaturation/hydroxylation activity of castor stearoyl Δ9-Desaturase through rational mutagenesis

Tupec

Culka

Machara

et al. 2022

Computational and Structural Biotechnology Journal

View full text Add to dashboard Cite

“…∆ 9 -palmitoyl-ACP desaturases identified in several plant species prefer 16:0 (palmitic acid) instead of 18:0 as a substrate, resulting in the production of ω-7 16:1 [28][29][30]. The ∆ 4 -and ∆ 6 -palmitoyl-ACP desaturases respectively identified in Coriandrum sativum (coriander) and Thunbergia alata (black-eyed Susan vine) also use 16:0 as a preferential substrate, but differ in their regiospecificity, leading to the production of ω-12 16:1 (∆ 4 hexadecanoic acid) and ω-10 16:1 (∆ 6 hexadecenoic acid) [31,32].…”

Section: Synthesis Of Monounsaturated Fatty Acids By Acyl-acyl Carriementioning

confidence: 99%

Acyl–Acyl Carrier Protein Desaturases and Plant Biotic Interactions

Kazaz

Miray

Baud

2021

Cells

View full text Add to dashboard Cite

Interactions between land plants and other organisms such as pathogens, pollinators, or symbionts usually involve a variety of specialized effectors participating in complex cross-talks between organisms. Fatty acids and their lipid derivatives play important roles in these biological interactions. While the transcriptional regulation of genes encoding acyl–acyl carrier protein (ACP) desaturases appears to be largely responsive to biotic stress, the different monounsaturated fatty acids produced by these enzymes were shown to take active part in plant biotic interactions and were assigned with specific functions intrinsically linked to the position of the carbon–carbon double bond within their acyl chain. For example, oleic acid, an omega-9 monounsaturated fatty acid produced by Δ9-stearoyl–ACP desaturases, participates in signal transduction pathways affecting plant immunity against pathogen infection. Myristoleic acid, an omega-5 monounsaturated fatty acid produced by Δ9-myristoyl–ACP desaturases, serves as a precursor for the biosynthesis of omega-5 anacardic acids that are active biocides against pests. Finally, different types of monounsaturated fatty acids synthesized in the labellum of orchids are used for the production of a variety of alkenes participating in the chemistry of sexual deception, hence favoring plant pollination by hymenopterans.

show abstract

delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

Cited by 77 publications

References 35 publications

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ⁹ Desaturase

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ⁹ Desaturase

Understanding desaturation/hydroxylation activity of castor stearoyl Δ9-Desaturase through rational mutagenesis

Acyl–Acyl Carrier Protein Desaturases and Plant Biotic Interactions

Contact Info

Product

Resources

About

delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

Cited by 77 publications

References 35 publications

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ9 Desaturase

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ9 Desaturase

Understanding desaturation/hydroxylation activity of castor stearoyl Δ9-Desaturase through rational mutagenesis

Acyl–Acyl Carrier Protein Desaturases and Plant Biotic Interactions

Contact Info

Product

Resources

About

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ⁹ Desaturase

Role of Hydrophobic Partitioning in Substrate Selectivity and Turnover of the Ricinus communis Stearoyl Acyl Carrier Protein Δ⁹ Desaturase