mu-conotoxin GIIIA, a peptide ligand for muscle sodium channels: Chemical synthesis, radiolabeling, and receptor characterization
The peptide conotoxin GIIIA from Conus geographus L. venom, which specifically blocks sodium channels in muscle, has been synthesized by a solid-phase method. The three disulfide bridges were formed by air oxidation. After HPLC purification, the synthetic product was shown to be identical with the native conotoxin GIIIA from Conus geographus. A high specific activity, /sup 125/I derivative of mu-conotoxin was prepared and used for binding assays to the Na channel from Electrophorus electric organ. Specific binding could be abolished by competition with tetrodotoxin. The radiolabeled toxin was specifically cross-linked to the Na channel. These studies demonstrate that mu-conotoxin GIIIA can be used to define the guanidinium toxin binding site and will be a useful ligand for understanding functionally important differences between Na channel subtypes.
- Research Organization:
- Clayton Foundation Laboratories for Peptide Biology, La Jolla, CA (USA)
- OSTI ID:
- 5823133
- Journal Information:
- Biochemistry; (United States), Vol. 28:8
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MOLLUSCS
ELECTROPHYSIOLOGY
PEPTIDES
RECEPTORS
CHEMICAL COMPOSITION
BIOCHEMICAL REACTION KINETICS
CHEMICAL PREPARATION
IN VITRO
IODINE 125
LABELLING
LIGANDS
LIQUID COLUMN CHROMATOGRAPHY
MEMBRANE TRANSPORT
RADIOASSAY
SODIUM
TOXINS
TRACER TECHNIQUES
ALKALI METALS
ANIMALS
ANTIGENS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
INTERMEDIATE MASS NUCLEI
INVERTEBRATES
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MATERIALS
MEMBRANE PROTEINS
METALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHYSIOLOGY
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SEPARATION PROCESSES
SYNTHESIS
TOXIC MATERIALS
550201* - Biochemistry- Tracer Techniques