Gamma-aminobutyric acid-modulated benzodiazepine binding sites in bacteria

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Life Sciences; (United States)

DOI:https://doi.org/10.1016/0024-3205(91)90595-3· OSTI ID:5865500

Lummis, S C.R.; Johnston, G A.R. ^[1]; Nicoletti, G ^[2]; Holan, G ^[3]

---

1. Univ. of Sydney, New South Wales (Australia)
2. Royal Melbourne Inst. of Tech. (Australia)
3. CSIRO, Melbourne (Australia)

Benzodiazepine binding sites, which were once considered to exist only in higher vertebrates, are here demonstrated in the bacteria E. coli. The bacterial ({sup 3}H)diazepam binding sites are modulated by GABA; the modulation is dose dependent and is reduced at high concentrations. The most potent competitors of E.Coli ({sup 3}H)diazepam binding are those that are active in displacing ({sup 3}H)benzodiazepines from vertebrate peripheral benzodiazepine binding sites. These vertebrate sites are not modulated by GABA, in contrast to vertebrate neuronal benzodiazepine binding sites. The E.coli benzodiazepine binding sites therefore differ from both classes of vertebrate benzodiazepine binding sites; however the ligand spectrum and GABA-modulatory properties of the E.coli sites are similar to those found in insects. This intermediate type of receptor in lower species suggests a precursor for at least one class of vertebrate benzodiazepine binding sites may have existed.

• OSTI ID: 5865500
• Journal Information: Life Sciences; (United States), Vol. 49:15; ISSN 0024-3205
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AMINOBUTYRIC ACID
BIOCHEMICAL REACTION KINETICS
ESCHERICHIA COLI
BIOCHEMISTRY
SYMPATHOMIMETICS
RECEPTORS
DOSE-RESPONSE RELATIONSHIPS
LIGANDS
TRACER TECHNIQUES
ULTRAVIOLET RADIATION
AMINO ACIDS
AUTONOMIC NERVOUS SYSTEM AGENTS
BACTERIA
CARBOXYLIC ACIDS
CHEMISTRY
DRUGS
ELECTROMAGNETIC RADIATION
ISOTOPE APPLICATIONS
KINETICS
MEMBRANE PROTEINS
MICROORGANISMS
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
RADIATIONS
REACTION KINETICS
550201* - Biochemistry- Tracer Techniques