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Structure and action of snake neurotoxins
Abstracts of Papers
157
Tin, N., SeTO, S., ENno, Y., SEI'O, A. and Yore, H., Tohoku University, Department of Chemistry, Katahiracho, Seadai, Japan Stroctm~e aad actioo of enake aemotoains Snake neurotoxins were isolated from the vesoms of Laticauda sem(fasciata (erabutoxins a, b, and c) (Tea~mre and ARAI, 1966), L. laticaudata and L. colubrina (latiootoxin a) (Sero et al., 1969), Bungarus jasciatus and Naja naja of Philippine Islands. All of them are small molecular basic proteins consisting of 62 amino acid residues. The amino acid sequence and the positions of disulphide bridges of erabutoxins a and b were elucidated. It was found that there are common features with a-toxin (EAYER and PORATH, 1967), cobrotoxin (YANß, 1969 ; Yexo et al., 1969) or Nqja hgje a-toxin (Bores and S~rRVnoN, 1969) of cobras in the amino acid sequence . The tryptophan residue at the 29th position of erabutoxins is essential for the toxicity because it is found in common is all sea snake and cobratoxins, the structures of which were elucidated, and the toxins lose the toxicity on its modification. Histidine-26 of erabutoxin b is not essential. It is replaced with other amino acids in other toxins and can be modified without loss of the activity . It was already reported by one of the authors that the toxins attack the post-synaptic membrane of a aeuro-muscular junction competing with the physiological transmitter, acetylcholise (Termre and ÀRAI, 1966) . In vivo experiments with radio-iodine containing erabutoxin b (at His-26) showed that the toxin combined selectively with mouse diaphragm endplates. The erabutoxins are immunogenic. The tryptic core of erabutoxin b inhibits the neutralizing activity of the antisera against the toxin. The erabutoxins cross-react with anti-a-toxin sera . The biosynthesis of laticotoxin a seems to follow the general mechanism of the protein biosynthesis, although the toxin molecule is rather small as a protein. The inoorporatioa of radioactive amino acids into the toxin molecule in vivo (L . laticaudata) is inhibited by the addition of puromycin ($eT0 et al., 1969). REFERENCES BOTES, L. B. and STRYDON, D. J. (1969)1. btol. Chem. 244, 4147 . Ee~t, D. L.andPORATH, J. (1967) 7th International Ca;gress ofBiochemistry, Tokyo, Col. VIII-3 Abstracts III, p. 499. Tokyo : The Science Council of Japan. SATO, S., YosmDn, H. and TMmre, N. (1969) Biochem. J. 115, 85 . TMUSre, N. and ARAI, H. (1966) Biochem. J. 99, 624. Yexa, C. C. (1969) J. biol. Chem. 240, 1616 . Yexa, C. C., YeNa, H. J. and Htrexa, J. S. (1969) Biochem. biophys . Acts 188, 65. TRSn~wre, E. R., University of Melbourne, Department of Physiology, Parkville, Victoria, Australia Diagnosis of type of soaks in soaks bite Fluid obtained from the region of snake bite in guinea-pigs (using tiger snake, brown snake and death adder) produces a sharp precipitation with the specific antivenins when placed in wells in gel-diffusion agar . When dried venom is igjected into the thigh of guinea-pigs, there is much cross reaction between tiger snake, brown snake, death adder, copperhead, Taipan and black snake antivenene from fluid obtained from the site of the igjection. However, one can detect the type of venom from the more definitive precipitation against the homologous antivenins . When a fresher preparation of dried venom is used, there is less overlap in reaction . There is a difference in the line distribution of antivenins precipitation from the black snake and death adder when run against the appropriate (old) dried venom . This may relate to the histamine releasing properties and haemolytic factor is the contained venom which are sharply contrasted with these venoms . The changes is reaction with drying of the venom wmpared with live snake bite is worthy of further investigation . The possibility of polymerization or breakdown of protein moieties on keeping cannot be excluded. TRIEFF, N. M., Srt~s, J. J., ReY, S. M. and Nesx, J. B., University of Texas Medical Branch, Department of Pharmacology and Toxicology, Galveston, and Texas A and M University, Marine Laboratory, Galveston, Texas, U.S .A. Isolation of Gyna~o~m breve toxin The toxin from the dinoflagellate, Gymnodinium breve, previously reported by McFeRREN et al. (1965) to cause symptoms of paralytic shellfish poisoning, was isolated by a thin layer chromatographic (TLC,) procedure and partially characterized by physico-chemical and toxicological studies. The isolation procedars consisted of ether extraction of acidified c~iltures of G. breve, evaporation of the ether, and successive migrations of the acetone-soluble portion of the residue on TLC silica gel plates . The first migration used a TLC-4GF plate (Mallinckrodt), and a developer of benzene-ethyl acetate-ethanol-acetic acid (79 : 10 : 10 : 1) ; the toxin appeared in several closely spaced bands with R~0~41-0~49 . l;a the second migration,
157
Tin, N., SeTO, S., ENno, Y., SEI'O, A. and Yore, H., Tohoku University, Department of Chemistry, Katahiracho, Seadai, Japan Stroctm~e aad actioo of enake aemotoains Snake neurotoxins were isolated from the vesoms of Laticauda sem(fasciata (erabutoxins a, b, and c) (Tea~mre and ARAI, 1966), L. laticaudata and L. colubrina (latiootoxin a) (Sero et al., 1969), Bungarus jasciatus and Naja naja of Philippine Islands. All of them are small molecular basic proteins consisting of 62 amino acid residues. The amino acid sequence and the positions of disulphide bridges of erabutoxins a and b were elucidated. It was found that there are common features with a-toxin (EAYER and PORATH, 1967), cobrotoxin (YANß, 1969 ; Yexo et al., 1969) or Nqja hgje a-toxin (Bores and S~rRVnoN, 1969) of cobras in the amino acid sequence . The tryptophan residue at the 29th position of erabutoxins is essential for the toxicity because it is found in common is all sea snake and cobratoxins, the structures of which were elucidated, and the toxins lose the toxicity on its modification. Histidine-26 of erabutoxin b is not essential. It is replaced with other amino acids in other toxins and can be modified without loss of the activity . It was already reported by one of the authors that the toxins attack the post-synaptic membrane of a aeuro-muscular junction competing with the physiological transmitter, acetylcholise (Termre and ÀRAI, 1966) . In vivo experiments with radio-iodine containing erabutoxin b (at His-26) showed that the toxin combined selectively with mouse diaphragm endplates. The erabutoxins are immunogenic. The tryptic core of erabutoxin b inhibits the neutralizing activity of the antisera against the toxin. The erabutoxins cross-react with anti-a-toxin sera . The biosynthesis of laticotoxin a seems to follow the general mechanism of the protein biosynthesis, although the toxin molecule is rather small as a protein. The inoorporatioa of radioactive amino acids into the toxin molecule in vivo (L . laticaudata) is inhibited by the addition of puromycin ($eT0 et al., 1969). REFERENCES BOTES, L. B. and STRYDON, D. J. (1969)1. btol. Chem. 244, 4147 . Ee~t, D. L.andPORATH, J. (1967) 7th International Ca;gress ofBiochemistry, Tokyo, Col. VIII-3 Abstracts III, p. 499. Tokyo : The Science Council of Japan. SATO, S., YosmDn, H. and TMmre, N. (1969) Biochem. J. 115, 85 . TMUSre, N. and ARAI, H. (1966) Biochem. J. 99, 624. Yexa, C. C. (1969) J. biol. Chem. 240, 1616 . Yexa, C. C., YeNa, H. J. and Htrexa, J. S. (1969) Biochem. biophys . Acts 188, 65. TRSn~wre, E. R., University of Melbourne, Department of Physiology, Parkville, Victoria, Australia Diagnosis of type of soaks in soaks bite Fluid obtained from the region of snake bite in guinea-pigs (using tiger snake, brown snake and death adder) produces a sharp precipitation with the specific antivenins when placed in wells in gel-diffusion agar . When dried venom is igjected into the thigh of guinea-pigs, there is much cross reaction between tiger snake, brown snake, death adder, copperhead, Taipan and black snake antivenene from fluid obtained from the site of the igjection. However, one can detect the type of venom from the more definitive precipitation against the homologous antivenins . When a fresher preparation of dried venom is used, there is less overlap in reaction . There is a difference in the line distribution of antivenins precipitation from the black snake and death adder when run against the appropriate (old) dried venom . This may relate to the histamine releasing properties and haemolytic factor is the contained venom which are sharply contrasted with these venoms . The changes is reaction with drying of the venom wmpared with live snake bite is worthy of further investigation . The possibility of polymerization or breakdown of protein moieties on keeping cannot be excluded. TRIEFF, N. M., Srt~s, J. J., ReY, S. M. and Nesx, J. B., University of Texas Medical Branch, Department of Pharmacology and Toxicology, Galveston, and Texas A and M University, Marine Laboratory, Galveston, Texas, U.S .A. Isolation of Gyna~o~m breve toxin The toxin from the dinoflagellate, Gymnodinium breve, previously reported by McFeRREN et al. (1965) to cause symptoms of paralytic shellfish poisoning, was isolated by a thin layer chromatographic (TLC,) procedure and partially characterized by physico-chemical and toxicological studies. The isolation procedars consisted of ether extraction of acidified c~iltures of G. breve, evaporation of the ether, and successive migrations of the acetone-soluble portion of the residue on TLC silica gel plates . The first migration used a TLC-4GF plate (Mallinckrodt), and a developer of benzene-ethyl acetate-ethanol-acetic acid (79 : 10 : 10 : 1) ; the toxin appeared in several closely spaced bands with R~0~41-0~49 . l;a the second migration,