Limits...
African adders: partial characterization of snake venoms from three Bitis species of medical importance and their neutralization by experimental equine antivenoms.

Paixão-Cavalcante D, Kuniyoshi AK, Portaro FC, da Silva WD, Tambourgi DV - PLoS Negl Trop Dis (2015)

Bottom Line: The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies.Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

View Article: PubMed Central - PubMed

Affiliation: Immunochemistry Laboratory, Butantan Institute, São Paulo, São Paulo, Brazil.

ABSTRACT

Background: An alarming number of fatal accidents involving snakes are annually reported in Africa and most of the victims suffer from permanent local tissue damage and chronic disabilities. Envenomation by snakes belonging to the genus Bitis, Viperidae family, are common in Sub-Saharan Africa. The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies. In this study we have biochemically characterized venoms from three different species of Bitis, i.e., Bitis arietans, Bitis gabonica rhinoceros and Bitis nasicornis, involved in the majority of the human accidents in Africa, and analyzed the in vitro neutralizing ability of two experimental antivenoms.

Methodology/principal findings: The data indicate that all venoms presented phospholipase, hyaluronidase and fibrinogenolytic activities and cleaved efficiently the FRET substrate Abz-RPPGFSPFRQ-EDDnp and angiotensin I, generating angiotensin 1-7. Gelatinolytic activity was only observed in the venoms of B. arietans and B. nasicornis. The treatment of the venoms with protease inhibitors indicated that Bitis venoms possess metallo and serinoproteases enzymes, which may be involved in the different biological activities here evaluated. Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.

Conclusion: These results suggest that the venoms of the three Bitis species, involved in accidents with humans in the Sub-Saharan Africa, contain a mixture of various enzymes that may act in the generation and development of some of the clinical manifestations of the envenomations. We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

No MeSH data available.


Related in: MedlinePlus

Cleavage of Angiotensin I by Bitis ssp venoms and identification of the cleavage sites on the primary sequence.[A] Angiotensin I (65 μM) was incubated at 37°C with 1 μg of Bitis arietans venom (1 h/37°C) or 5 μg of B. nasicornis or B. g. rhinoceros venoms (2 h/37°C) in phosphate buffer (50 mM sodium phosphate, 20 mM NaCl, pH 7.4). In parallel, the venoms were pre-incubated, 30 min prior the addition of angiotensin I, with PHE (5 mM), PMSF (5 mM) or EDTA (100 mM). [B] The hydrolysis products, collected during the reverse-phase chromatography, were submitted to mass spectrometry analysis. All venoms cleaved angiotensin I in different cleavage sites. The lines indicate the cleavage sites on angiotensin I primary sequence after treatment with the different Bitis venoms. The bold solid line indicates the cleavage point for angiotensin 1–7 generation and the solid lines indicate the other cleavage points observed after the treatment with the venoms. The dashed line indicates the sites on angiotensin I primary sequence cleaved only by B. g. rhinoceros and B. nasicornis venoms.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4340965&req=5

pntd.0003419.g005: Cleavage of Angiotensin I by Bitis ssp venoms and identification of the cleavage sites on the primary sequence.[A] Angiotensin I (65 μM) was incubated at 37°C with 1 μg of Bitis arietans venom (1 h/37°C) or 5 μg of B. nasicornis or B. g. rhinoceros venoms (2 h/37°C) in phosphate buffer (50 mM sodium phosphate, 20 mM NaCl, pH 7.4). In parallel, the venoms were pre-incubated, 30 min prior the addition of angiotensin I, with PHE (5 mM), PMSF (5 mM) or EDTA (100 mM). [B] The hydrolysis products, collected during the reverse-phase chromatography, were submitted to mass spectrometry analysis. All venoms cleaved angiotensin I in different cleavage sites. The lines indicate the cleavage sites on angiotensin I primary sequence after treatment with the different Bitis venoms. The bold solid line indicates the cleavage point for angiotensin 1–7 generation and the solid lines indicate the other cleavage points observed after the treatment with the venoms. The dashed line indicates the sites on angiotensin I primary sequence cleaved only by B. g. rhinoceros and B. nasicornis venoms.

Mentions: All Bitis venoms showed ability to cleave the FRET substrate, the peptide Abz-RPPGFSPFRQ-EDDnp (Fig. 4). B. arietans venom presented a specific activity of ~6000 UF/min/μg, which was completely inhibited by both EDTA and phenanthroline. B. g rhinoceros venom showed a specific proteolytic activity of ~7000 UF/min/μg, which was only inhibited by phenanthroline. B. nasicornis venom presented a specific proteolytic activity of ~7500 UF/min μg/, which was abolished by PMSF, but not for EDTA or phenanthroline. All the venoms also directly cleaved the angiotensin I generating angiotensin 1–7 (Fig. 5B). Besides angiotensin 1–7, the cleavage of angiotensin I generated several fragments with molecular weight varying from 770 to 1170 Da (Fig. 5B). B. arietans was more active in the cleavage of angiotensin I than B. g. rhinoceros and B. nasicornis. For all venoms, this proteolytic activity was completely abolished by PHE and EDTA, but not by PMSF (Fig. 5A).


African adders: partial characterization of snake venoms from three Bitis species of medical importance and their neutralization by experimental equine antivenoms.

Paixão-Cavalcante D, Kuniyoshi AK, Portaro FC, da Silva WD, Tambourgi DV - PLoS Negl Trop Dis (2015)

Cleavage of Angiotensin I by Bitis ssp venoms and identification of the cleavage sites on the primary sequence.[A] Angiotensin I (65 μM) was incubated at 37°C with 1 μg of Bitis arietans venom (1 h/37°C) or 5 μg of B. nasicornis or B. g. rhinoceros venoms (2 h/37°C) in phosphate buffer (50 mM sodium phosphate, 20 mM NaCl, pH 7.4). In parallel, the venoms were pre-incubated, 30 min prior the addition of angiotensin I, with PHE (5 mM), PMSF (5 mM) or EDTA (100 mM). [B] The hydrolysis products, collected during the reverse-phase chromatography, were submitted to mass spectrometry analysis. All venoms cleaved angiotensin I in different cleavage sites. The lines indicate the cleavage sites on angiotensin I primary sequence after treatment with the different Bitis venoms. The bold solid line indicates the cleavage point for angiotensin 1–7 generation and the solid lines indicate the other cleavage points observed after the treatment with the venoms. The dashed line indicates the sites on angiotensin I primary sequence cleaved only by B. g. rhinoceros and B. nasicornis venoms.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340965&req=5

pntd.0003419.g005: Cleavage of Angiotensin I by Bitis ssp venoms and identification of the cleavage sites on the primary sequence.[A] Angiotensin I (65 μM) was incubated at 37°C with 1 μg of Bitis arietans venom (1 h/37°C) or 5 μg of B. nasicornis or B. g. rhinoceros venoms (2 h/37°C) in phosphate buffer (50 mM sodium phosphate, 20 mM NaCl, pH 7.4). In parallel, the venoms were pre-incubated, 30 min prior the addition of angiotensin I, with PHE (5 mM), PMSF (5 mM) or EDTA (100 mM). [B] The hydrolysis products, collected during the reverse-phase chromatography, were submitted to mass spectrometry analysis. All venoms cleaved angiotensin I in different cleavage sites. The lines indicate the cleavage sites on angiotensin I primary sequence after treatment with the different Bitis venoms. The bold solid line indicates the cleavage point for angiotensin 1–7 generation and the solid lines indicate the other cleavage points observed after the treatment with the venoms. The dashed line indicates the sites on angiotensin I primary sequence cleaved only by B. g. rhinoceros and B. nasicornis venoms.
Mentions: All Bitis venoms showed ability to cleave the FRET substrate, the peptide Abz-RPPGFSPFRQ-EDDnp (Fig. 4). B. arietans venom presented a specific activity of ~6000 UF/min/μg, which was completely inhibited by both EDTA and phenanthroline. B. g rhinoceros venom showed a specific proteolytic activity of ~7000 UF/min/μg, which was only inhibited by phenanthroline. B. nasicornis venom presented a specific proteolytic activity of ~7500 UF/min μg/, which was abolished by PMSF, but not for EDTA or phenanthroline. All the venoms also directly cleaved the angiotensin I generating angiotensin 1–7 (Fig. 5B). Besides angiotensin 1–7, the cleavage of angiotensin I generated several fragments with molecular weight varying from 770 to 1170 Da (Fig. 5B). B. arietans was more active in the cleavage of angiotensin I than B. g. rhinoceros and B. nasicornis. For all venoms, this proteolytic activity was completely abolished by PHE and EDTA, but not by PMSF (Fig. 5A).

Bottom Line: The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies.Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

View Article: PubMed Central - PubMed

Affiliation: Immunochemistry Laboratory, Butantan Institute, São Paulo, São Paulo, Brazil.

ABSTRACT

Background: An alarming number of fatal accidents involving snakes are annually reported in Africa and most of the victims suffer from permanent local tissue damage and chronic disabilities. Envenomation by snakes belonging to the genus Bitis, Viperidae family, are common in Sub-Saharan Africa. The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies. In this study we have biochemically characterized venoms from three different species of Bitis, i.e., Bitis arietans, Bitis gabonica rhinoceros and Bitis nasicornis, involved in the majority of the human accidents in Africa, and analyzed the in vitro neutralizing ability of two experimental antivenoms.

Methodology/principal findings: The data indicate that all venoms presented phospholipase, hyaluronidase and fibrinogenolytic activities and cleaved efficiently the FRET substrate Abz-RPPGFSPFRQ-EDDnp and angiotensin I, generating angiotensin 1-7. Gelatinolytic activity was only observed in the venoms of B. arietans and B. nasicornis. The treatment of the venoms with protease inhibitors indicated that Bitis venoms possess metallo and serinoproteases enzymes, which may be involved in the different biological activities here evaluated. Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.

Conclusion: These results suggest that the venoms of the three Bitis species, involved in accidents with humans in the Sub-Saharan Africa, contain a mixture of various enzymes that may act in the generation and development of some of the clinical manifestations of the envenomations. We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

No MeSH data available.


Related in: MedlinePlus