Radioiodination of scorpion and snake toxins. [/sup 125/I, /sup 127/I]
Several scorpion and snake toxins were radioiodinated using the lactoperoxydase method of (/sup 125/I)iodide oxidation. Two techniques of labeling were set up: Using carrier-free Na/sup 125/I and 5 ..mu..g of toxin, about one iodine atom was incorporated per mole of protein without loss of toxicity. Specific radioactivities about 2,000 Ci/mmol (280 ..mu..Ci/..mu..g) were obtained. The modified toxin, purified by immunoprecipitation with an antiserum prepared against the native toxin, was obtained in a short time (4 hr), with a good yield (50 to 80%), and in a small volume (1 ml). Using Na/sup 127/I traced with Na /sup 125/I and larger amounts (200 ..mu..g) of toxin, more than one iodine atom was incorporated per mole of protein without loss of activity. Lower specific radioactivities (1 to 1.5 Ci/mmol) were obtained. The iodinated toxins were purified by gel filtration of the radioiodination mixtures on a column made of two layers of Sephadex (G-15 and G-50). The modified proteins were extensively analyzed by paper electrophoresis and polyacrylamide gel electrophoresis. Their content of monoiodotyrosine and diiodotyrosine was estimated and, in the case of toxin I of Androctonus australis Hector, it was possible to follow the iodination rate of its three tyrosine residues by automatic Edman degradation. The mode of purification of the iodinated scorpion toxins affects their behavior on molecular sieving on Sephadex G-50 and on electrophoresis on polyacrylamide gel. The results are discussed.
- Research Organization:
- Laboratoire de Biochimie, Marseille
- OSTI ID:
- 5045982
- Journal Information:
- Anal. Biochem.; (United States), Journal Name: Anal. Biochem.; (United States) Vol. 82:2; ISSN ANBCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ANTIGENS
ARACHNIDS
ARTHROPODS
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INVERTEBRATES
IODINE 125
IODINE 127
IODINE ISOTOPES
ISOTOPES
LABELLING
NUCLEI
ODD-EVEN NUCLEI
PURIFICATION
RADIOISOTOPES
REPTILES
SCORPIONS
SNAKES
STABLE ISOTOPES
TOXIC MATERIALS
TOXINS
VERTEBRATES