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Drug
Enzyme
Compound
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Query: UNIPROT:P00750 (
PLA
)
16,800
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The effect of epsilon-aminocaproyl-S-benzyl-
L-cysteine
on the activation of plasminogen by
t-PA
. streptokinase and urokinase has been examined using fibrinolytic method. The obtained results have been compared with the obtained results for epsilon-aminocaproic acid and trans-4-(aminomethyl)cyclohexanecarboxylic acid. The inhibition of the plasminogen activation determined with the use of epsilon-aminocaproyl-S-benzyl-
L-cysteine
was weaker than the inhibition determined by using antifibrinolytic aminoacids.
...
PMID:Effect of epsilon-aminocaproyl-S-benzyl-L-cysteine on the activity of plasminogen activators. 1922 66
We report the proteomic characterization of the venom of the medically important North American western diamondback rattlesnake, Crotalus atrox, using two complementary approaches: snake venomics (to gain an insight of the overall venom proteome), and two solid-phase combinatorial peptide ligand libraries (CPLL), followed by 2D electrophoresis and mass spectrometric characterization of in-gel digested protein bands (to capture and "amplify" low-abundance proteins). The venomics approach revealed approximately 24 distinct proteins belonging to 2 major protein families (snake venom metalloproteinases, SVMP, and serine proteinases), which represent 69.5% of the total venom proteins, 4 medium abundance families (medium-size disintegrin,
PLA
(2),
cysteine
-rich secretory protein, and l-amino acid oxidase) amounting to 25.8% of the venom proteins, and 3 minor protein families (vasoactive peptides, endogenous inhibitor of SVMP, and C-type lectin-like). This toxin profile potentially explains the cytotoxic, myotoxic, hemotoxic, and hemorrhagic effects evoked by C. atrox envenomation. Further, our results showing that C. atrox exhibits a similar level of venom variation as Sistrurus miliarius points to a "diversity gain" scenario in the lineage leading to the Sistrurus catenatus taxa. On the other hand, the two combinatorial hexapeptide libraries captured distinct sets of proteins. Although the CPLL-treated samples did not retain a representative venom proteome, protein spots barely, or not at all, detectable in the whole venom were enriched in the two CPLL-treated samples. The amplified low copy number C. atrox venom proteins comprised a C-type lectin-like protein, several
PLA
(2) molecules, PIII-SVMP isoforms, glutaminyl cyclase isoforms, and a 2-cys peroxiredoxin highly conserved across the animal kingdom. Peroxiredoxin and glutaminyl cyclase may participate, respectively, in redox processes leading to the structural/functional diversification of toxins, and in the N-terminal pyrrolidone carboxylic acid formation required in the maturation of bioactive peptides such as bradykinin-potentiating peptides and endogenous inhibitors of metalloproteases. Our findings underscore the usefulness of combinatorial peptide libraries as powerful tools for mining below the tip of the iceberg, complementing thereby the data gained using the snake venomics protocol toward a complete visualization of the venom proteome.
...
PMID:Exploring the venom proteome of the western diamondback rattlesnake, Crotalus atrox, via snake venomics and combinatorial peptide ligand library approaches. 1937 Nov 36
The mechanisms of cell death induced by hypoxia or ischemia are not yet fully understood. We have previously demonstrated that cell death induced by hypoxia occurs independently of caspases, and is mediated by phospholipase A(2) (
PLA
(2)). Here, we show that p38 mitogen-activated protein kinase is activated under hypoxia. A selective inhibitor of p38 or decrease in the p38alpha protein level prevents hypoxia-induced cell death. The p38 inhibitor abolishes
PLA
(2) activation by hypoxia, indicating that p38 acts upstream of
PLA
(2). The antioxidant N-acetyl-
cysteine
inhibits activation of p38 and cell death induced by hypoxia, indicating that reactive oxygen species (ROS) are responsible for p38 activation. These results demonstrate that the ROS/p38/
PLA
(2) signaling axis has a crucial role in caspase-independent cell death induced by hypoxia.
...
PMID:Essential role of p38 MAPK in caspase-independent, iPLA(2)-dependent cell death under hypoxia/low glucose conditions. 1939 51
We report the purification and biochemical/pharmacological characterization of two myotoxic
PLA
(2) (BbTX-II K49
PLA
(2) homologue and BbTX-III
PLA
(2)) from Bothrops brazili venom. Both were purified by a single chromatographic step on reverse phase HPLC, showing M(r) approximately 14 kDa for both myotoxins, showing high content of hydrophobic and basic amino acids as well as 14 half-
cysteine
residues. The BbTX-II K49
PLA
(2) homologue and BbTX-III
PLA
(2), had a sequence of 121 amino acid residues. BbTX-II: [amino acid sequence: see text] with pI value 8.73. BbTX-III: [amino acid sequence: see text] with a pI value of 8.46. BbTX-III presented
PLA
(2) activity in the presence of a synthetic substrate and showed a minimum sigmoidal behavior, reaching its maximal activity at pH 8.0 and 35-45 degrees C. Maximum
PLA
(2) activity required Ca(2+). In vitro, BbTX-II K49
PLA
(2) homologue and BbTX-III
PLA
(2) caused a blockade of the neuromuscular transmission in young chick biventer cervicis preparations in a similar way to other Bothrops species. In mice, BbTX-II K49
PLA
(2) homologue and BbTX-III
PLA
(2) induces myonecrosis and edema-forming activity. All these biological effects induced by the BbTX-II K49
PLA
(2) homologue, occur in the absence of a measurable
PLA
(2) activity in vitro, further supporting the concept of catalytic independent mechanisms exerted by Lys49 proteins.
...
PMID:Structural and functional characterization of brazilitoxins II and III (BbTX-II and -III), two myotoxins from the venom of Bothrops brazili snake. 1953 40
Phospholipase A(2) (
PLA
(2)) is one of the main components of bee venom. Here, we identify a venom
PLA
(2) from the bumblebee, Bombus ignitus. Bumblebee venom
PLA
(2) (Bi-
PLA
(2)) cDNA, which was identified by searching B. ignitus venom gland expressed sequence tags, encodes a 180 amino acid protein. Comparison of the genomic sequence with the cDNA sequence revealed the presence of four exons and three introns in the Bi-
PLA
(2) gene. Bi-
PLA
(2) is an 18-kDa glycoprotein. It is expressed in the venom gland, cleaved between the residues Arg44 and Ile45, and then stored in the venom sac. Comparative analysis revealed that the mature Bi-
PLA
(2) (136 amino acids) possesses features consistent with other bee
PLA
(2)s, including ten conserved
cysteine
residues, as well as a highly conserved Ca(2+)-binding site and active site. Phylogenetic analysis of bee
PLA
(2)s separated the bumblebee and honeybee
PLA
(2) proteins into two groups. The mature Bi-
PLA
(2) purified from the venom of B. ignitus worker bees hydrolyzed DBPC, a known substrate of
PLA
(2). Immunofluorescence staining of Bi-
PLA
(2)-treated insect Sf9 cells revealed that Bi-
PLA
(2) binds at the cell membrane and induces apoptotic cell death.
...
PMID:Molecular cloning and characterization of a venom phospholipase A2 from the bumblebee Bombus ignitus. 1953 76
Intraspecific snake venom variations have implications in the preparation of venom pools for the generation of antivenoms. The impact of such variation in the cross-reactivity of antivenoms against Bothrops asper venom was assessed by comparing two commercial and four experimental antivenoms. All antivenoms showed similar immunorecognition pattern toward the venoms from adult and neonate specimens. They completely immunodepleted most P-III snake venom metalloproteinases (SVMPs), l-amino acid oxidases, serine proteinases, DC fragments,
cysteine
-rich secretory proteins (CRISPs), and C-type lectin-like proteins, and partially immunodepleted medium-sized disintegrins, phospholipases A(2) (
PLA
(2)s), some serine proteinases, and P-I SVMPs. Although all antivenoms abrogated the lethal, hemorrhagic, coagulant, proteinase, and
PLA
(2) venoms activities, monospecific experimental antivenoms were more effective than the polyspecific experimental antivenom. In addition, the commercial antivenoms, produced in horses subjected to repeated immunization cycles, showed higher neutralization than experimental polyspecific antivenom, produced by a single round of immunization. Overall, a conspicuous pattern of cross-neutralization was evident for all effects by all antivenoms, and monospecific antivenoms raised against venom from the Caribbean population were effective against venom from the Pacific population, indicating that geographic variations in venom proteomes of B. asper from Costa Rica do not result in overt variations in immunological cross-reactivity between antivenoms.
...
PMID:Impact of regional variation in Bothrops asper snake venom on the design of antivenoms: integrating antivenomics and neutralization approaches. 1991 49
A combination of anti-bothropic and anti-crotalic sera has been reported to be more effective in neutralizing the effects of Bothrops jararacussu venom than anti-bothropic serum alone. The role of proteins from B. jararacussu venom in the horse immune response was evaluated via the analysis of cross-reactivity with homologous and heterologous sera. Many of the proteins in B. jararacussu venom were identified via 2D gel electrophoresis. Western blots revealed that anti-jararacussu showed higher reactivity to l-aminoxidase (LAOs) and snake venom metalloproteinase, (SVMPs) and weaker reactivity towards Snake venom serine proteases (SVSPs),
PLA
(2), C-type lectin and
cysteine
-rich proteins. Anti-jararaca preferentially recognized LAOs, SVMPs and SVSPs. Both of these sera failed to recognize low-molecular weight proteins. Anti-crotalic serum clearly recognized LAOs, C-type lectin, SVSP,
cysteine
-rich proteins, SVMP and Asp49-
PLA
(2). The cross-reactivity with anti-
PLA
(2) revealed the immunoreactivity of these antibodies to proteins with molecular masses in a range that is poorly recognized by other studied anti-sera. Our results suggest that the contribution of anti-crotalic serum to the neutralization of B. jararacussu by may be due to its cross-reactivity with proteins such as C-type lectins, SVSPs, Asp49-
PLA
(2). These results also reinforce the importance of neutralizing the highly toxic proteins inclusive those with low immunogenicity in commercial antivenom production to obtain a highly protective serum against snake venoms.
...
PMID:Immunome and venome of Bothrops jararacussu: a proteomic approach to study the molecular immunology of snake toxins. 2006 13
Peroxiredoxins (Prx) are enzymes that catalyze the reduction of hydrogen peroxide and alkyl hydroperoxides. Prxs are ubiquitous enzymes with representatives found in Bacteria, Archaea and Eukarya. Many 1-
cysteine
peroxiredoxins (1-CysPrx) are dual-function enzyme with both peroxidase and acidic Ca(2+)-independent phospholipase A(2) (aiPLA(2)) activities. The functions proposed for 1-CysPrx/aiPLA(2) include the protection of cell membrane phospholipids against oxidative damage (peroxidation) and the metabolism (hydrolysis) of phospholipids, such as those of lung surfactant. The peroxidase active site motif PVCTTE of 1-CysPrx contains the conserved catalytic
cysteine
residue, and the esterase (lipase) motif GXSXG of the enzyme contains the conserved catalytic serine residue. In addition to the classic lipase motif GXSXG, various 1-CysPrx/aiPLA(2)s have closely related variant putative lipase motifs containing the catalytic serine residue. The
PLA
(2) moieties are prevalent and highly homologous in vertebrate and bacterial 1-CysPrx/aiPLA(2)s that is consistent with a high degree evolutional conservation of the enzyme.
...
PMID:1-Cysteine peroxiredoxin: A dual-function enzyme with peroxidase and acidic Ca2+-independent phospholipase A2 activities. 2013 8
To examine the molecular diversity of the venom proteins of the Russell's viper (Daboia russellii russellii) and the Indian cobra (Naja naja) in Sri Lanka, we isolated 38 venom proteins through a combination of anion exchange chromatography followed by reversed-phase high performance liquid chromatography. From the venom of D. r. russellii we isolated 15 proteins: 5 isozymes of phospholipase A(2) (
PLA
(2)), 4 serine proteases, 2 C-type lectin-like proteins, 2 L-amino acid oxidases, 1
cysteine
-rich secretory protein (CRISP), and 1 metalloproteinase. From the venom of N. naja we isolated 23 proteins: 10 isoforms of cytotoxins (CTX), 7
PLA
(2) isozymes, 2 muscarinic toxinlike proteins, 2 CRISPs, 1 nerve growth factor, and 1 new thrombin-like serine protease. Most of these proteins contained new amino acid sequences for each species, indicating molecular diversity in venom proteins. The entire amino acid sequences of
PLA
(2)3 from D. r. russellii and CTX7 from N. naja were determined. Additionally, the polymorphic amino acid residues of
PLA
(2)3 were preferentially localized on the potential antigenic sites. While 2 types of
PLA
(2) (N and S types) were found in D. r. russellii (India) and D. r. siamensis (Java), all the
PLA
(2)s from D. r. siamensis (Burma) were N type, and those from D. r. russellii (Sri Lanka) were primarily S type.
...
PMID:Molecular diversity in venom proteins of the Russell's viper (Daboia russellii russellii) and the Indian cobra (Naja naja) in Sri Lanka. 2020 22
We report the comparative proteomic and antivenomic characterization of the venoms of subspecies cascavella and collilineatus of the Brazilian tropical rattlesnake Crotalus durissus. The venom proteomes of C. d. collilineatus and C. d. cascavella comprise proteins in the range of 4-115 kDa belonging to 9 and 8 toxin families, respectively. Collilineatus and cascavella venoms contain 20-25 main toxins belonging to the following protein families: disintegrin,
PLA
(2), serine proteinase,
cysteine
-rich secretory protein (CRISP), vascular endothelial growth factor-like (VEGF), L-amino acid oxidase, C-type lectin-like, and snake venom metalloproteinase (SVMP). As judged by reverse-phase HPLC and mass spectrometry, cascavella and collilineatus share about 90% of their venom proteome. However, the relative occurrence of the toxin families departs among the two C. durissus subspecies venoms. The most notable difference is the presence of the myotoxin crotamine in some C. d. collilineatus specimens (averaging 20.8% of the total proteins of pooled venom), which is absent in the venom of C. d. cascavella. On the other hand, the neurotoxic
PLA
(2) crotoxin represents the most abundant protein in both C. durissus venoms, comprising 67.4% of the toxin proteome in C. d. collilineatus and 72.5% in C. d. cascavella. Myotoxic
PLA
(2)s are also present in the two venoms albeit in different relative concentrations (18.1% in C. d. cascavella vs. 4.6% in C. d. collilineatus). The venom composition accounts for the clinical manifestations caused by C. durissus envenomations: systemic neurotoxicity and myalgic symptoms and coagulation disturbances, frequently accompanied by myoglobinuria and acute renal failure. The overall compositions of C. d. subspecies cascavella and collilineatus venoms closely resemble that of C. d. terrificus, supporting the view that these taxa can be considered geographical variations of the same species. Pooled venom from adult C.d. cascavella and neonate C.d. terrificus lack crotamine, whereas this skeletal muscle cell membrane depolarizing inducing myotoxin accounts for approximately 20% of the total toxins of venom pooled from C.d. collilineatus and C.d. terrificus from Southern Brazil. The possible relevance of the observed venom variability among the tropical rattlesnake subspecies was assessed by antivenomics using anti-crotalic antivenoms produced at Instituto Butantan and Instituto Vital Brazil. The results revealed that both antivenoms exhibit impaired immunoreactivity towards crotamine and display restricted ( approximately 60%) recognition of
PLA
(2) molecules (crotoxin and D49-myotoxins) from C. d. cascavella and C. d. terrificus venoms. This poor reactivity of the antivenoms may be due to a combination of factors: on the one hand, an inappropriate choice of the mixture of venoms for immunization and, on the other hand, the documented low immunogenicity of
PLA
(2) molecules. C. durissus causes most of the lethal snakebite accidents in Brazil. The implication of the geographic variation of venom composition for the treatment of bites by different C. durissus subspecies populations is discussed.
...
PMID:Snake venomics and antivenomics of Crotalus durissus subspecies from Brazil: assessment of geographic variation and its implication on snakebite management. 2054 51
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