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 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 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 The primary structure of aspartate aminotransferase from pig heart muscle. Partial sequences determined by digestion with thermolysin and elastase

1973 ◽  
Vol 133 (4) ◽  
pp. 805-819 ◽  
Author(s):  
Francesco Bossa ◽  
Donatella Barra ◽  
Massimo Carloni ◽  
Paolo Fasella ◽  
Francesca Riva ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Primary Structure ◽  
Aspartate Aminotransferase ◽  
Heart Muscle ◽  
Science And Technology ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Lending Library

Peptides produced by thermolytic digestion of aminoethylated aspartate aminotransferase and of the oxidized enzyme were isolated and their amino acid sequences determined. Digestion by elastase of the carboxymethylated enzyme gave peptides representing approximately 40% of the primary structure. Fragments from these digests overlapped with previously reported sequences of peptides obtained by peptic and tryptic digestion (Doonan et al., 1972), giving ten composite peptides containing 395 amino acid residues. The amino acid composition of these composite peptides agrees well with that of the intact enzyme. Confirmatory results for some of the present data have been deposited as Supplementary Publication 50018 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973) 131, 5.

scholarly journals Primary Structure Analysis of Antifungal Peptides from Cultivated and Wild Cereals

Plants ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 74 ◽  
Author(s):  
Eugene Rogozhin ◽  
Dmitry Ryazantsev ◽  
Alexey Smirnov ◽  
Sergey Zavriev
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Antifungal Activity ◽  
Antimicrobial Peptides ◽  
Structure Analysis ◽  
Primary Structure ◽  
Biologically Active ◽  
Amino Acid Residues ◽  
Wild Cereals ◽  
Determining Factor

Cereal-derived bioactive peptides with antimicrobial activity have been poorly explored compared to those from dicotyledonous plants. Furthermore, there are a few reports addressing the structural differences between antimicrobial peptides (AMPs) from cultivated and wild cereals, which may shed light on significant varieties in the range and level of their antimicrobial activity. We performed a primary structure analysis of some antimicrobial peptides from wild and cultivated cereals to find out the features that are associated with the much higher antimicrobial resistance characteristic of wild plants. In this review, we identified and analyzed the main parameters determining significant antifungal activity. They relate to a high variability level in the sequences of C-terminal fragments and a high content of hydrophobic amino acid residues in the biologically active defensins in wild cereals, in contrast to AMPs from cultivated forms that usually exhibit weak, if any, activity. We analyzed the similarity of various physicochemical parameters between thionins and defensins. The presence of a high divergence on a fixed part of any polypeptide that is close to defensins could be a determining factor. For all of the currently known hevein-like peptides of cereals, we can say that the determining factor in this regard is the structure of the chitin-binding domain, and in particular, amino acid residues that are not directly involved in intermolecular interaction with chitin. The analysis of amino acid sequences of alpha-hairpinins (hairpin-like peptides) demonstrated much higher antifungal activity and more specificity of the peptides from wild cereals compared with those from wheat and corn, which may be associated with the presence of a mini cluster of positively charged amino acid residues. In addition, at least one hydrophobic residue may be responsible for binding to the components of fungal cell membranes.

scholarly journals The neurotoxins of the sea snake Laticauda schistorhynchus

1983 ◽  
Vol 213 (1) ◽  
pp. 39-41 ◽  
Author(s):  
M L Guinea ◽  
N Tamiya ◽  
H G Cogger
Keyword(s):  
Amino Acid ◽  
Electrophoretic Mobility ◽  
Column Chromatography ◽  
Amino Acid Analysis ◽  
Sea Snake ◽  
Laticauda Semifasciata ◽  
Cellulose Column

Erabutoxins a and b, the major neurotoxins in the venom of the sea snake Laticauda semifasciata, were detected in the venom of Laticauda schistorhynchus. The identity of the toxins was confirmed on the basis of elution position on CM-cellulose column chromatography, disc electrophoretic mobility, amino acid analysis and toxicity measurement.

scholarly journals Amino acid sequences of two novel long-chain neurotoxins from the venom of the sea snake Laticauda colubrina

1982 ◽  
Vol 207 (2) ◽  
pp. 215-223 ◽  
Author(s):  
H S Kim ◽  
N Tamiya
Keyword(s):  
Amino Acid ◽  
Intramuscular Injection ◽  
Solomon Islands ◽  
The Philippines ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Sea Snake ◽  
Novel Structure ◽  
Long Chain ◽  
Laticauda Colubrina

From the venom of a population of the sea snake Laticauda colubrina from the Solomon Islands, a neurotoxic component, Laticauda colubrina a (toxin Lc a), was isolated in 16.6% (A280) yield. Similarly, from the venom of a population of L. colubrina from the Philippines, a neurotoxic component, Laticauda colubrina b (toxin Lc b), was obtained in 10.0% (A280) yield. The LD50 values of these toxins were 0.12 microgram/g body wt. on intramuscular injection in mice. Toxins Lc a and Lc b were each composed of molecules containing 69 amino acid residues with eight half-cystine residues. The complete amino acid sequences of these two toxins were elucidated. Toxins Lc a and Lc b are different from each other at five positions of their sequences, namely at positions 31 (Phe/Ser), 32 (Leu/Ile), 33 (Lys/Arg), 50 (Pro/Arg) and 53 (Asp/His) (residues in parentheses give the residues in toxins Lc a and Lc b respectively). Toxins Lc a and Lc b have a novel structure in that they have only four disulphide bridges, although the whole amino acid sequences are homologous to those of other known long-chain neurotoxins. It is remarkable that toxins Lc a and Lc b are not coexistent at the detection error of 6% of the other toxin. Populations of Laticauda colubrina from the Solomon Islands and from the Philippines have either toxin Lc a or toxin Lc b and not both of them.

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