scholarly journals The amino acid sequences of erabutoxins, neurotoxic proteins of sea-snake (Laticauda semifasciata) venom

1971 ◽  
Vol 122 (4) ◽  
pp. 453-461 ◽  
Author(s):  
S. Sato ◽  
N. Tamiya

1. Erabutoxin b was reduced, S-carboxymethylated and hydrolysed with trypsin. Seven tryptic fragments were isolated by column chromatography and paper electrophoresis. Some of the fragments were further hydrolysed with α-chymotrypsin, pepsin, Nagarse, Proctase A or Proctase B. The amino acid sequences of the fragment peptides were determined by subtractive Edman degradation. 2. From the tryptic digest of reduced, S-carboxymethylated and trifluoroacetylated erabutoxin b two fragments were isolated. From the amino acid composition of the fragments and from the terminal sequence studies on the reduced and S-carboxymethylated erabutoxin b, the sequence of the above seven tryptic fragments was elucidated. 3. The tryptic digestion of reduced and S-carboxymethylated erabutoxin a gave fragments, only one of which was different from the corresponding fragment from erabutoxin b. The amino acid sequence analysis of the fragment peptide showed that the only difference between erabutoxins a and b was that the former had asparagine and the latter had histidine at position 26.

1967 ◽  
Vol 102 (3) ◽  
pp. 801-814 ◽  
Author(s):  
M. C. Corfield ◽  
J. C. Fletcher ◽  
A. Robson

1. A tryptic digest of the protein fraction U.S.3 from oxidized wool has been separated into 32 peptide fractions by cation-exchange resin chromatography. 2. Most of these fractions have been resolved into their component peptides by a combination of the techniques of cation-exchange resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid compositions of 58 of the peptides in the digest present in the largest amounts have been determined. 4. The amino acid sequences of 38 of these have been completely elucidated and those of six others partially derived. 5. These findings indicate that the parent protein in wool from which the protein fraction U.S.3 is derived has a minimum molecular weight of 74000. 6. The structures of wool proteins are discussed in the light of the peptide sequences determined, and, in particular, of those sequences in fraction U.S.3 that could not be elucidated.


1972 ◽  
Vol 130 (2) ◽  
pp. 547-555 ◽  
Author(s):  
N. Tamiya ◽  
H. Abe

Erabutoxin c, a minor neurotoxic component of the venom of a sea snake Laticauda semifasciata, was isolated in pure form by repeated column chromatography on CM-cellulose columns. The toxin was crystallizable and monodisperse in rechromatography, disc electrophoresis and isoelectric focusing (isoelectric point, pH9.23–9.25). The molecular weight of the toxin, as estimated by gel filtration, was 7000. The toxin showed the same lethal activity to mice (0.13μg/g body wt., intramuscular injection) and the same effect on isolated frog muscle as erabutoxins a and b, the main toxic components of the venom. The toxin inhibited the acetylcholine contracture but not the potassium chloride contracture of muscle. Erabutoxin c consisted of 62 amino acid residues, containing one fewer lysine and one more histidine than erabutoxin a and one fewer lysine and one more aspartic acid (or asparagine) than erabutoxin b. Erabutoxin c was reduced, S-carboxymethylated and hydrolysed with trypsin. The only fragment different from the corresponding fragments from erabutoxin b was hydrolysed further with pepsin. One of the peptic fragments, which was assumed to have the aspartic acid (or asparagine) residue in question at the C-terminal end, was treated with carboxypeptidase A. The C-terminal residue was found to be an asparagine. It was therefore concluded that erabutoxin c was [51-asparagine]-erabutoxin b.


1985 ◽  
Vol 226 (3) ◽  
pp. 879-880 ◽  
Author(s):  
S Nishida ◽  
Y Kokubun ◽  
N Tamiya

The amino acid sequences of erabutoxins a and b were reinvestigated. The previously reported sequences of Gln-His at positions 6 and 7, and of Pro-Ser at positions 18 and 19 of erabutoxins a and b were corrected to His-Gln and Ser-Pro respectively.


1982 ◽  
Vol 207 (3) ◽  
pp. 589-594 ◽  
Author(s):  
S Nishida ◽  
H S Kim ◽  
N Tamiya

Amino acid sequences of three phospholipases A, I, III and IV, from the venom of the sea snake Laticauda semifasciata were elucidated. Each protein consisted of a single chain of 118 amino acid residues, including 14 half-cystine residues. They showed high homology among themselves, and with the other snake-venom phospholipases A and with the enzymes from mammalian pancreas. Phospholipases A III and IV were especially similar to each other, with only four differences out of their 118 amino acid residues. Phospholipase A I contained one tryptophan residue at position 64, which was important for enzymic activity, whereas III and IV did not contain tryptophan residues and their corresponding positions were occupied by leucine residues. The substitution by leucine resulted in a decreased, but definite, phospholipase A activity. The substituted enzymes have a more potent neuromuscular blocking activity. Full experimental details and evidence for the amino acid sequences of the proteins have been deposited as Supplementary Publication SUP 50118 (39 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J.(1981)193,5.


1971 ◽  
Vol 122 (4) ◽  
pp. 463-467 ◽  
Author(s):  
Y. Endo ◽  
S. Sato ◽  
S. Ishii ◽  
N. Tamiya

Erabutoxin a was partially hydrolysed with enzymes and sulphuric acid and the resulting peptides were separated from each other by column chromatography and paper electrophoresis. From the results of amino acid analyses of the sulphur-containing peptides and their oxidized components, all four disulphide bridges in the toxin molecule were located. The disulphide bonds were found between half-cystine residues at positions 3 and 24, 17 and 41, 43 and 54, and 55 and 60 from the N-terminus.


1980 ◽  
Vol 187 (3) ◽  
pp. 863-874 ◽  
Author(s):  
D M Johnson ◽  
J Gagnon ◽  
K B Reid

The serine esterase factor D of the complement system was purified from outdated human plasma with a yield of 20% of the initial haemolytic activity found in serum. This represented an approx. 60 000-fold purification. The final product was homogeneous as judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (with an apparent mol.wt. of 24 000), its migration as a single component in a variety of fractionation procedures based on size and charge, and its N-terminal amino-acid-sequence analysis. The N-terminal amino acid sequence of the first 36 residues of the intact molecule was found to be homologous with the N-terminal amino acid sequences of the catalytic chains of other serine esterases. Factor D showed an especially strong homology (greater than 60% identity) with rat ‘group-specific protease’ [Woodbury, Katunuma, Kobayashi, Titani, & Neurath (1978) Biochemistry 17, 811-819] over the first 16 amino acid residues. This similarity is of interest since it is considered that both enzymes may be synthesized in their active, rather than zymogen, forms. The three major CNBr fragments of factor D, which had apparent mol.wts. of 15 800, 6600 and 1700, were purified and then aligned by N-terminal amino acid sequence analysis and amino acid analysis. By using factor D labelled with di-[1,3-14C]isopropylphosphofluoridate it was shown that the CNBr fragment of apparent mol.wt. 6600, which is located in the C-terminal region of factor D, contained the active serine residue. The amino acid sequence around this residue was determined.


1969 ◽  
Vol 22 (5) ◽  
pp. 1197 ◽  
Author(s):  
RL Darskus ◽  
JM Gillespie ◽  
H Lindley

S-Carboxymethyl derivatives of the high-sulphur components of reduced Merino wool have been subdivided by chromatography into 17 fractions, the amino acid compositions of which are reported. Tryptic, chymotryptic, and thermolysin digests of each fraction have been studied by high-voltage paper electrophoresis at pH 3�5 and 6�5. The results suggest that the high-sulphur proteins consist of families of proteins probably containing common structural features. Evidence is presented that the heterogeneity of high-sulphur proteins is not artefactual.


1987 ◽  
Vol 1 (2) ◽  
pp. 276-281 ◽  
Author(s):  
J.-H. Yeh ◽  
T. Takagi ◽  
S. Sasaki

Two peptide fractions of bovine amelogenin having a highly aggregative property to form polymers were purified by chromatography, SDS-polyacrylamide gel electrophoresis, and HPLC. Amino acid sequences of purified peptides were determined by automated Edman degradation. One peptide was found to be composed of 63 amino acid residues having a molecular weight of 7105, and the other of 86 residues having that of 9683. The sequence of the smaller peptide was identical to the C-terminal 63 residues of the amelogenin molecule of 170 residues previously reported, but the larger contained eight residues which are absent in the amelogenin sequence. There is a possibility that the latter peptide might be synthesized independently from mRNA spliced at different positions.


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