Inhibition of Vibrio harveyi bioluminescence by cerulenin: In vivo evidence for covalent modification of the reductase enzyme involved in aldehyde synthesis

Journal Article · Sat Jul 01 00:00:00 EDT 1989 · Journal of Bacteriology; (USA)

OSTI ID:5045355

Byers, D M ^[1]; Meighen, E A ^[2]

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1. Dalhousie Univ., Halifax (Nova Scotia)
2. McGill Univ., Montreal, Quebec (Canada)

Bacterial bioluminescence is very sensitive to cerulenin, a fungal antibiotic which is known to inhibit fatty acid synthesis. When Vibrio harveyi cells pretreated with cerulenin were incubated with ({sup 3}H)myristic acid in vivo, acylation of the 57-kilodalton reductase subunit of the luminescence-specific fatty acid reductase complex was specifically inhibited. Light emission of wild-type V. harveyi was 20-fold less sensitive to cerulenin at low concentrations (10{mu}g/ml) than that of the dark mutant strain M17, which requires exogenous myristic acid for luminescence because of a defective transferase subunit. The sensitivity of myristic acid-stimulated luminescence in the mutant strain M17 exceeded that of phospholipid synthesis from ({sup 14}C)acetate, whereas uptake and incorporation of exogenous ({sup 14}C)myristic acid into phospholipids was increased by cerulenin. The reductase subunit could be labeled by incubating M17 cells with ({sup 3}H)tetrahydrocerulenin; this labeling was prevented by preincubation with either unlabeled cerulenin or myristic acid. Labeling of the reductase subunit with ({sup 3}H)tetrahydrocerulenin was also noted in an aldehyde-stimulated mutant (A16) but not in wild-type cells or in another aldehyde-stimulated mutant (M42) in which ({sup 3}H)myristoyl turnover at the reductase subunit was found to be defective. These results indicate that (i) cerulenin specifically and covalently inhibits the reductase component of aldehyde synthesis, (ii) this enzyme is partially protected from cerulenin inhibition in the wild-type strain in vivo, and (iii) two dark mutants which exhibit similar luminescence phenotypes (mutants A16 and M42) are blocked at different stages of fatty acid reduction.

• OSTI ID: 5045355
• Journal Information: Journal of Bacteriology; (USA), Vol. 171:7; ISSN 0021-9193
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ANTIBIOTICS
BIOLOGICAL EFFECTS
BACTERIA
ENZYME ACTIVITY
BIOLUMINESCENCE
BIOCHEMICAL REACTION KINETICS
CARBOXYLIC ACIDS
INHIBITION
OXIDOREDUCTASES
TETRADECANOIC ACID
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANTI-INFECTIVE AGENTS
DRUGS
ENZYMES
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ISOTOPE APPLICATIONS
KINETICS
LUMINESCENCE
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550201* - Biochemistry- Tracer Techniques