Properties of radiolabeled. cap alpha. -bungarotoxin derivatives and their interaction with nicotinic acetylcholine receptors

Journal Article · Tue Jun 13 04:00:00 EDT 1978 · Biochemistry; (United States)

OSTI ID:7089344

Lukasiewicz, R J; Hanley, M R; Bennett, E L

Column-purified monoiodinated, diiodinated, and tritiated derivatives of ..cap alpha..-bungarotoxin (..cap alpha..-Bgt) are distinguished on the basis of their ultraviolet absorption and circular dichroism (CD) spectra. The pattern of changes in CD spectra on incorporation of iodine into a single tyrosine residue of ..cap alpha..-Bgt and the widespread wavelength distribution of these effects are interpreted as reflecting primary chemical modification of the tyrosine chromophore as well as vicinal and global secondary structural changes. Native and tritiated ..cap alpha..-Bgt are shown to be more effective than iodinated ..cap alpha..-Bgt derivatives in competing for specific tozin binding sites on putative nicotinic acetylcholine receptors (nACnR) derived from rat brain reflecting functional perturbation of the modified toxin. In contrast, both membrane-bound and solubilized nAChR from Torpedo californica electroplax display little or no specific binding preference for native toxin, nor are there significant differences in lethal potency of ..cap alpha..-Bgt derivatives toward mice. These results suggest that peripheral and putative central nAChR may differ in their ..cap alpha..-Bgt binding properties and suggest the usefulness of modified toxin in detecting those subtle differences.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 7089344
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 17:12; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702 -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
AMINES
AMINO ACIDS
AMMONIUM COMPOUNDS
ANIMALS
ANTIGENS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CHEMICAL BONDS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
DAYS LIVING RADIOISOTOPES
DRUGS
EEL
ELECTRON CAPTURE RADIOISOTOPES
ESTERS
FISHES
HALOGENATION
HYDROXY ACIDS
INTERMEDIATE MASS NUCLEI
IODINATION
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MOLECULAR STRUCTURE
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PARASYMPATHOMIMETICS
QUATERNARY COMPOUNDS
RADIOISOTOPES
RATS
RECEPTORS
REPTILES
RODENTS
SNAKES
TOXIC MATERIALS
TOXINS
TRITIUM COMPOUNDS
TYROSINE
VENOMS
VERTEBRATES