| Title: |
Esterification of vertebrate-type steroids in the Eastern oyster (Crassostrea virginica).
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| Resource Type: |
document --> technical publication --> journal article
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| Country: |
EU Projects
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| Year: |
2004 |
| Availability: |
Janer G, Mesia-Vela S, Porte C, Kauffman FC (2004): Esterification of vertebrate-type steroids in the Eastern oyster (Crassostrea virginica). Steroids 69, 129-136
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| Author 1/Producer: |
Janer G
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| Other Authors/Producers: |
Mesia-Vela S, Porte C, Kauffman FC
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| Author / Producer Type: |
EC Project
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| Format (e.g. PDF): |
PDF
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EUGRIS Keyword(s): |
Contaminated land-->Contaminants-->Contaminants overview
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| Short description: |
Characteristics of acyl-coenzyme A (acyl-CoA):steroid acyltransferase from the digestive gland of the oyster Crassostrea virginica were determined by using estradiol (E2) and dehydroepiandrosterone (DHEA) as substrates. The apparent Km and Vmax values for esterification of E2 with the six fatty acid acyl-CoAs tested (C20:4, C18:2, C18:1, C16:1, C18:0, and C16:0) were in the range of 9–17 M E2 and 35–74 pmol/min/mg protein, respectively. Kinetic parameters for esterification of DHEA (Km: 45–120M; Vmax: 30–182 pmol/min/mg protein) showed a lower affinity of the enzyme for this steroid. Formation of endogenous fatty acid esters of steroids by microsomes of digestive gland and gonads incubated in the presence of ATP and CoA was assessed, and at least seven E2 fatty acid esters and five DHEA fatty acid esters were observed. Some peaks eluted at the same retention times as palmitoleoyl-, linoleoyl-, oleoyl/palmitoyl-, and stearoyl-E2; and palmitoleoyl-, oleoyl/palmitoyl-, and stearoyl-DHEA. The same endogenous esters, although in different proportions, were produced by gonadal microsomes. The kinetic parameters for both E2 (Km: 10M; Vmax: 38 pmol/min/mg protein) and DHEA (Km:
61 M; Vmax: 60 pmol/min/mg protein) were similar to those obtained in the digestive gland. Kinetic parameters obtained are similar to those observed in mammals; thus, fatty acid esterification of sex steroids appears to be a well-conserved conjugation pathway during evolution.
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Submitted By:
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Dr Stefan Gödeke WhoDoesWhat?
Last update: 14/02/2006
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