scholarly journals The amino acid sequence and position of the free thiol group of a short-chain neurotoxin from common-death-adder (Acanthophis antarcticus) venom

1981 ◽  
Vol 199 (1) ◽  
pp. 211-218 ◽  
Author(s):  
H S Kim ◽  
N Tamiya

The amino acid sequence of a short-chain neurotoxin Acanthophis antarcticus c (toxin Aa c) from the venom of an Australian elapid snake, the common death adder (Acanthophis antarcticus, subfamily Acanthophiinae) was elucidated. Toxin Aa c is composed of 62 amino acid residues, including eight half-cystine residues and a cysteine residue. The amino acid sequence of toxin Aa c is homologous with those of other short-chain neurotoxins found in snakes of the family Elapidae, especially with those from snakes of the subfamily Hydrophiinae. The single cysteine residue was located in position 4. Toxin Aa c has a lethal dose (LD50) of 0.08 micrograms/g body weight of mouse on intramuscular injection.

1971 ◽  
Vol 124 (1) ◽  
pp. 61-67 ◽  
Author(s):  
P. H. Corran ◽  
S. G. Waley

1. Calf lens α-crystallin was carboxymethylated with radioactive sodium iodoacetate to label the thiol group. 2. The protein was then digested with trypsin or alternatively fractionated in urea to obtain the acidic (A) chains, which were then digested with trypsin. Either procedure gave two radioactive peptides containing carboxymethylcysteine. 3. These two peptides were closely related: the longer form contained 28 amino acid residues, and the shorter lacked two residues at the N-terminal end of the longer form. 4. The amino acid sequence of the peptides have been determined. 5. No evidence for the presence of more than one cysteine residue/chain was found. 6. The question of the molecular weight of the chains is discussed.


1990 ◽  
Vol 266 (1) ◽  
pp. 221-225 ◽  
Author(s):  
T Suzuki ◽  
T Takagi ◽  
S Ohta

The deep-sea tube worm Lamellibrachia, belonging to the Phylum Vestimentifera, contains two giant extracellular haemoglobins, a 3000 kDa haemoglobin and a 440 kDa haemoglobin. The former consists of four haem-containing chains (AI-AIV) and two linker chains (AV and AVI) for the assembly of the haem-containing chains [Suzuki, Takagi & Ohta (1988) Biochem. J. 255, 541-545]. The tube-worm haemoglobins are believed to have a function of transporting sulphide (H2S) to internal bacterial symbionts, as well as of facilitating O2 transport [Arp & Childress (1983) Science 219, 295-297]. We have determined the complete amino acid sequence of Lamellibrachia chain AIII by automated or manual Edman sequencing. The chain is composed of 144 amino acid residues, has three cysteine residues at positions 3, 74 and 133, and has a molecular mass of 16,620 Da, including a haem group. The sequence showed significant homology (30-50% identity) with those of haem-containing chains of annelid giant haemoglobins. Two of the three cysteine residues are located at the positions where an intrachain disulphide bridge is formed in all annelid chains, but the remaining one (Cys-74) was located at a unique position, compared with annelid chains. Since the chain AIII was shown to have a reactive thiol group in the intact 3000 kDa molecule by preliminary experiments, the cysteine residue at position 74 appears to be one of the most probable candidates for the sulphide-binding sites. A phylogenetic tree was constructed from nine chains of annelid giant haemoglobins and one chain of vestimentiferan tube-worm haemoglobin now determined. The tree clearly showed that Lamellibrachia chain AIII belongs to the family of strain A of annelid giant haemoglobins, and that the two classes of Annelida, polychaete and oligochaete, and the vestimentiferan tube worm diverged at almost the same time. H.p.l.c. patterns of peptides (Figs. 4-7), amino acid compositions of peptides (Table 2) and amino acid sequences of intact protein and peptides (Table 3) have been deposited as Supplementary Publication SUP 50154 (13 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1990) 265, 5.


2000 ◽  
Vol 182 (9) ◽  
pp. 2536-2543 ◽  
Author(s):  
Rachel A. L. Lassy ◽  
Charles G. Miller

ABSTRACT Salmonella enterica serovar Typhimurium peptidase E (PepE) is an N-terminal Asp-specific dipeptidase. PepE is not inhibited by any of the classical peptidase inhibitors, and its amino acid sequence does not place it in any of the known peptidase structural classes. A comparison of the amino acid sequence of PepE with a number of related sequences has allowed us to define the amino acid residues that are strongly conserved in this family. To ensure the validity of this comparison, we have expressed one of the most distantly related relatives (Xenopus) in Escherichia coli and have shown that it is indeed an Asp-specific dipeptidase with properties very similar to those of serovar Typhimurium PepE. The sequence comparison suggests that PepE is a serine hydrolase. We have used site-directed mutagenesis to change all of the conserved Ser, His, and Asp residues and have found that Ser120, His157, and Asp135 are all required for activity. Conversion of Ser120 to Cys leads to severely reduced (104-fold) but still detectable activity, and this activity but not that of the parent is inhibited by thiol reagents; these results confirm that this residue is likely to be the catalytic nucleophile. These results suggest that PepE is the prototype of a new family of serine peptidases. The phylogenetic distribution of the family is unusual, since representatives are found in eubacteria, an insect (Drosophila), and a vertebrate (Xenopus) but not in the Archaea or in any of the other eukaryotes for which genome sequences are available.


2018 ◽  
Vol 62 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Sergiy M. Boiko

Pool of intracellular endoglucanases of the fungus Schizophyllum commune on the territory of Ukraine was studied. Two loci of endoglucanase (Eg1, Eg2) were found. The polymorphic locus Eg2 controls the expression of four alleles. Alleles Eg293, Eg296 and Eg2102 are rare and peculiar to certain populations. Amino acid sequence of the locus Eg2 in databases of NCBI (XP_003031634.1) and UniProt (D8Q439) was probably identified. It is classified among the family 5 (GH5) and consists of 333 amino acid residues.


1977 ◽  
Vol 161 (1) ◽  
pp. 189-192 ◽  
Author(s):  
R A Maurer ◽  
J Gorski ◽  
D J McKean

Rat pituitary mRNA was used to direct the cell-free synthesis of pre-prolactin labelled with [4,5-3H]leucine and either [35S] methioninc or [35S] cystine. Sequence analysis of the labelled protein indicates that pre-prolactin has 29 amino acid residues joined to the N-terminus of the prolactin sequence. Leucine residues were found at positions 13, 14, 15, 16, 21 and 22, methionine residues at positions 1, 17 and 18, and a cysteine residue at position 24 of the precursor sequence, and this partial sequence shows considerable similarity with other precursors that have been sequenced.


1985 ◽  
Vol 232 (2) ◽  
pp. 367-371 ◽  
Author(s):  
C Takasaki ◽  
N Tamiya

A short-chain neurotoxin Pseudechis australis a (toxin Pa a) was isolated from the venom of an Australian elapid snake Pseudechis australis (king brown snake) by sequential chromatography on CM-cellulose, Sephadex G-50 and CM-cellulose columns. Toxin Pa a has an LD50 (intravenous) value of 76 micrograms/kg body wt. in mice and consists of 62 amino acid residues. The amino acid sequence of Pa a shows considerable homology with those of short-chain neurotoxins of elapid snakes, especially of true sea snakes.


1981 ◽  
Vol 193 (3) ◽  
pp. 899-906 ◽  
Author(s):  
H S Kim ◽  
N Tamiya

The venom of an Australian elapid snake, the common death adder (Acanthophis antarcticus), was chromatographed on a CM-cellulose CM52 column. One of the neurotoxic components, Acanthophis antarcticus b (toxin Aa b) was isolated in about 9.4% (A280) yield. The complete amino acid sequence of toxin Aa b was elucidated. Toxin Aa b is composed of 73 amino acid residues, with ten half-cystine residues, and has a formula weight of 8135. Toxin Aa b has no histidine or methionine residue in its sequence. The amino acid sequence of toxin Aa b is homologous with those of other neurotoxins with known sequences, although it is novel in having a valine residue at its N-terminus and an arginine residue at position-23, where a lysine residue is found in almost all the so-far-known neurotoxins. Irrespective of the latter replacement, the toxin Aa b is fully active, with an LD50 value (in mice) of 0.13 microgram/g body weight on intramuscular injection.


1990 ◽  
Vol 266 (1) ◽  
pp. 75-81 ◽  
Author(s):  
D C Watson ◽  
M Yaguchi ◽  
K R Lynn

Chymopapain is a polypeptide of 218 amino acid residues. It has considerable structural similarity with papain and papaya proteinase omega, including conservation of the catalytic site and of the disulphide bonding. Chymopapain is like papaya proteinase omega in carrying four extra residues between papain positions 168 and 169, but differs from both papaya proteinases in the composition of its S2 subsite, as well as in having a second thiol group, Cys-117. Some evidence for the amino acid sequence of chymopapain has been deposited as Supplementary Publication SUP 50153 (12 pages) at the British Library Document Supply Centre, Boston Spa., Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms indicated in Biochem. J. (1990) 265, 5. The information comprises Supplement Tables 1-4, which contain, in order, amino acid compositions of peptides from tryptic, peptic, CNBr and mild acid cleavages, Supplement Fig. 1, showing re-fractionation of selected peaks from Fig. 2 of the main paper. Supplement Fig. 2, showing cation-exchange chromatography of the earliest-eluted peak of Fig. 3 of the main paper, Supplement Fig. 3, showing reverse-phase h.p.l.c. of the later-eluted peak from Fig. 3 of the main paper, and Supplement Fig. 4, showing the separation of peptides after mild acid hydrolysis of CNBr-cleavage fragment CB3.


1977 ◽  
Vol 163 (2) ◽  
pp. 309-316 ◽  
Author(s):  
I A Simpson ◽  
M R Hollaway ◽  
J Beard

1. The single highly reactive (class I) thiol group per 80000-mol.wt. subunit of skeletal-muscle phosphofructokinase was specifically carboxymethylated with iodo[2-14C]acetate, and after denaturation the remaining thiol groups were carboxymethylated with bromo[2-3H]acetate. After tryptic digestion and peptide ‘mapping’ it was found that the 14C radioactivity was in a spot that did not contain significant amounts of 3H radioactivity, so it is concluded that there is not a second, ‘buried’ cysteine residue within a sequence identical with that of the class-I cysteine peptide. 2. The total number of tryptic peptides as well as the number of those containing cysteine, histidine or tryptophan were inconsistent with the smallest polypeptide chain of phosphofructokinase (mol.wt. about 80000) being composed of two identical amino acid sequences. 3. The amino acid sequence of the tryptic peptide containing the class-I thiol group was shown to be Cys-Lys-Asp-Phe-Arg. This sequence is compared with part of the sequence containing the highly reactive thiol group of phosphorylase.


1989 ◽  
Vol 54 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Ivan Kluh ◽  
Ladislav Morávek ◽  
Manfred Pavlík

Cyanogen bromide fragment CB5 represents the region of the polypeptide chain of hemopexin between the fourth and fifth methionine residue (residues 232-352). It contains 120 amino acid residues in the following sequence: Arg-Cys-Ser-Pro-His-Leu-Val-Leu-Ser-Ala-Leu-Thr-Ser-Asp-Asn-His-Gly-Ala-Thr-Tyr-Ala-Phe-Ser-Gly-Thr-His-Tyr-Trp-Arg-Leu-Asp-Thr-Ser-Arg-Asp-Gly-Trp-His-Ser-Trp-Pro-Ile-Ala-His-Gln-Trp-Pro-Gln-Gly-Pro-Ser-Ala-Val-Asp-Ala-Ala-Phe-Ser-Trp-Glu-Glu-Lys-Leu-Tyr-Leu-Val-Gln-Gly-Thr-Gln-Val-Tyr-Val-Phe-Leu-Thr-Lys-Gly-Gly-Tyr-Thr-Leu-Val-Ser-Gly-Tyr-Pro-Lys-Arg-Leu-Glu-Lys-Glu-Val-Gly-Thr-Pro-His-Gly-Ile-Ile-Leu-Asp-Ser-Val-Asp-Ala-Ala-Phe-Ile-Cys-Pro-Gly-Ser-Ser-Arg-Leu-His-Ile-Met. The sequence was derived from the data on peptides prepared by cleavage of fragment CB5 by mild acid hydrolysis, by trypsin and chymotrypsin.


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