scholarly journals The isolation, properties and amino acid sequence of erabutoxin c, a minor neurotoxic component of the venom of a sea snake Laticauda semifasciata

1972 ◽  
Vol 130 (2) ◽  
pp. 547-555 ◽  
Author(s):  
N. Tamiya ◽  
H. Abe
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Gel Filtration ◽  
Disc Electrophoresis ◽  
Amino Acid Residues ◽  
Sea Snake ◽  
Acetylcholine Contracture ◽  
Laticauda Semifasciata ◽  
A Minor ◽  
Erabutoxin B

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.

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
Keyword(s):  
Amino Acid ◽  
Paper Electrophoresis ◽  
Amino Acid Sequences ◽  
Edman Degradation ◽  
Terminal Sequence ◽  
Amino Acid Sequence Analysis ◽  
Sea Snake ◽  
Tryptic Digest ◽  
Laticauda Semifasciata ◽  
Erabutoxin B

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.

scholarly journals The primary structure of the toxin Laticauda semifasciata III, a weak and reversibly acting neurotoxin from the venom of a sea snake, Laticauda semifasciata

1974 ◽  
Vol 141 (2) ◽  
pp. 389-400 ◽  
Author(s):  
Nobuyo Maeda ◽  
Nobuo Tamiya
Keyword(s):  
Amino Acid ◽  
Primary Structure ◽  
Amino Acid Residues ◽  
Sea Snake ◽  
Sea Snakes ◽  
Laticauda Semifasciata

A weak and reversibly acting neurotoxic protein of Laticauda semifasciata venom, Laticauda semifasciata III (component LsIII), was sequenced. Component LsIII consists of 66 amino acid residues and has five disulphide bridges, one of which was located between residues 26 and 30. The weak and reversible neurotoxicity of component LsIII is discussed in relation to its structure, which falls between those of the neuro- and cardiotoxins of sea snakes and Elapidae snakes isolated and sequenced so far.

scholarly journals Amino acid sequences of three phospholipases A I, III and IV from the venom of the sea snake Laticauda semifasciata

1982 ◽  
Vol 207 (3) ◽  
pp. 589-594 ◽  
Author(s):  
S Nishida ◽  
H S Kim ◽  
N Tamiya
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Phospholipase A ◽  
Tryptophan Residue ◽  
British Library ◽  
Amino Acid Residues ◽  
Single Chain ◽  
Sea Snake ◽  
Laticauda Semifasciata ◽  
Phospholipases A

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.

scholarly journals Properties and biosynthesis of a neurotoxic protein of the venoms of sea snakes Laticauda laticaudata and Laticauda colubrina

1969 ◽  
Vol 115 (1) ◽  
pp. 85-90 ◽  
Author(s):  
S. Sato ◽  
H. Yoshida ◽  
H. Abe ◽  
N. Tamiya
Keyword(s):  
Amino Acid ◽  
Protein Biosynthesis ◽  
Lethal Dose ◽  
Postsynaptic Membrane ◽  
Disc Electrophoresis ◽  
Amino Acid Residues ◽  
Sea Snakes ◽  
Laticauda Semifasciata ◽  
Laticauda Colubrina

1. A neurotoxic protein similar to erabutoxins a and b of Laticauda semifasciata was isolated in crystalline form from the venoms of Laticauda laticaudata and Laticauda colubrina. The name ‘laticotoxin a’ is proposed. 2. Laticotoxin a is homogeneous by CM-cellulose column chromatography, disc electrophoresis and ultracentrifugation and by terminal amino acid analyses. 3. Laticotoxin a consists of 62 amino acid residues. The molecular weight by ultracentrifuging is 6520. 4. The minimal 50% lethal dose of laticotoxin a by intramuscular injection to mice is 0·13μg./g. body wt. The toxin attacks the postsynaptic membrane, competing with acetylcholine. 5. Radioactive amino acids are incorporated into laticotoxin a in vivo. The incorporation is inhibited by puromycin, suggesting that the biosynthesis of the toxin follows the mechanism of protein biosynthesis, although the toxin molecule is rather small as a protein.

scholarly journals Isolation, properties and amino acid sequences of three neurotoxins from the venom of a sea snake, Aipysurus laevis

1976 ◽  
Vol 153 (1) ◽  
pp. 79-87 ◽  
Author(s):  
N Maeda ◽  
N Tamiya
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Disc Electrophoresis ◽  
Amino Acid Sequences ◽  
Peptide Sequence ◽  
Amino Acid Residues ◽  
Toxin B ◽  
Almost All

Aipysurus laevis venom was chromatographed on CM-cellulose and Bio-Rex 70 columns. Three neurotoxic components, toxins Aipysurus laevis a, b and c, were isolated. The toxins a, b and c corresponded to 22, 33 and 21% respectively of the proteins in the original venom, and accounted for almost all the lethal activity of the venom. The three toxins a, b and c were monodisperse on disc electrophoresis at pH4; toxins a and b moved at the same velocity and c a little faster. They were monodisperse also on sodium dodecyl sulphate-polyacrylamide-disc-gel electrophoresis, giving a molecular weight of 7600. The molecular weight of toxin b estimated by gel filtration was 7000. The amino acid sequence analyses of these toxins revealed that they consisted of 60 amino acid residues and that Aipysurus laevis b was [25-methionine, 28-arginine] Aipysurus laevis a. Aipysurus laevis c was [28-lysine] Aipysurus laevis a, the tryptic peptide sequence relying on homology. The LD50 values of these toxins for 20g mice were 0.076 μg/g body wt. They inhibited the acetylcholine-induced contracture but did not affect the CKl-induced contracture of the isolated muscle.

scholarly journals Rat liver alcohol dehydrogenase. Purification and properties

1971 ◽  
Vol 125 (4) ◽  
pp. 1039-1047 ◽  
Author(s):  
M J Arslanian ◽  
E Pascoe ◽  
J G Reinhold
Keyword(s):  
Molecular Weight ◽  
Alcohol Dehydrogenase ◽  
Rat Liver ◽  
Gel Filtration ◽  
Rabbit Antiserum ◽  
Minor Component ◽  
Disc Electrophoresis ◽  
Supernatant Fraction ◽  
Liver Alcohol Dehydrogenase ◽  
A Minor

Alcohol dehydrogenase (EC 1.1.1.1) from the rat liver supernatant fraction has been purified 200-fold and partially characterized. The isolation procedure involved ammonium sulphate fractionation, DEAE-Sephadex chromatography and gel filtration. The purified enzyme behaved as a homogeneous preparation as evaluated by cellulose acetate and polyacrylamide-gel disc electrophoresis. Sulphoethyl-Sephadex chromatography and immunoelectrophoresis with rabbit antiserum indicated the presence of a minor component. Rat liver alcohol dehydrogenase appears to contain 4mol of zinc/mol, has an estimated molecular weight of 65000 and consists of two subunits of similar molecular weight. Heavy-metal ions, thiol-blocking reagents, urea at concentrations below 8m, low pH (5.5) and chelating agents deactivate the enzyme but do not dissociate it into subunits. Deactivated enzyme could not be reactivated. The enzyme is strictly specific for NAD+ and has a broad specificity for alcohols, which are bound at a hydrophobic site. Inhibition occurred with the enzyme equilibrated with Zn2+ at concentrations above 0.1mm.

Studies on Chymotrypsin-P. I. Characterization

1971 ◽  
Vol 49 (9) ◽  
pp. 999-1004 ◽  
Author(s):  
M. C. Shaw ◽  
T. Viswanatha
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Physicochemical Properties ◽  
Gel Filtration ◽  
Amino Acid Residues ◽  
The Difference ◽  
Filtration Technique

The physicochemical properties of chymotrypsin-P obtained by the papain activation of chymotrypsinogen have been investigated. The molecular weight of this enzyme as determined by gel filtration technique has been found to be 24 000 ± 1000. The amino acid residues occupying the N-terminal positions and the composition of the B- and C-chains of chymotrypsin-P are identical with those found in α-chymotrypsin. Thus the difference between the two enzymes is restricted to the composition of their A-chains.

scholarly journals Isoelectric points of erabutoxins and monoacyl derivatives of erabutoxin b. Estimation of the pK values of amino groups in erabutoxins by using isoelectric-focusing data

1982 ◽  
Vol 203 (2) ◽  
pp. 427-433 ◽  
Author(s):  
N UI ◽  
C Takasaki ◽  
N Tamiya
Keyword(s):  
Isoelectric Focusing ◽  
Isoelectric Point ◽  
Amino Group ◽  
Amino Groups ◽  
Sea Snake ◽  
Isoelectric Points ◽  
Point Data ◽  
Laticauda Semifasciata ◽  
Erabutoxin B ◽  
Derivatives Of

The isoelectric points of erabutoxins a, b and c, neurotoxic proteins of a sea snake, Laticauda semifasciata, were determined by density-gradient isoelectric focusing. The same measurement was also made with monoacyl derivatives of erabutoxin b, in which each one of all amino groups had been either acetylated or propionylated. Erabutoxins a and b showed the same isoelectric point at pH 9.68. The values for [1-N alpha-acetyl-arginine]-, [15-N6-acetyl-lysine]-, [27-N6-acetyl-lysine]-, [47-N6-propionyl-lysine]- and [51-N6-acetyl-lysine]-erabutoxin b were at pH 9.52, 9.31, 9.45, 9.22 and 9.09 respectively, being definitely different from each other and lower than the value for the unmodified molecule. The isoelectric point of erabutoxin c, which is [51-asparagine]-erabutoxin b, was the same as that of [51-N6-acetyl-lysine]erabutoxin b. Assuming that no change in pK occurs on monoacylation, the pK values of amino groups in erabutoxin b were calculated from the isoelectric-point data. It is indicated that the pK values of zeta-amino groups differ markedly from each other and that the value of alpha-amino group is anomalously high.

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