Open AccessFunctional analysis of DM64, an antimyotoxic protein with immunoglobulin‐like structure from Didelphis marsupialis serum
Author(s) -
Rocha Surza L. G.,
Lomonte Bruno,
NevesFerreira Ana G. C.,
Trugilho Monique R. O.,
JunqueiradeAzevedo Inácio de L. M.,
Ho Paulo L.,
Domont Gilberto B.,
Gutiérrez José M.,
Perales Jonas
Publication year - 2002
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1033.2002.03308.x
Subject(s) - bothrops jararaca , didelphis , bothrops , snake venom , myotoxin , venom , disintegrin , biochemistry , biology , opossum , microbiology and biotechnology , antivenom , chemistry , metalloproteinase , enzyme , anatomy
Bothrops snake venoms are known to induce local tissue damage such as hemorrhage and myonecrosis. The opossum Didelphis marsupialis is resistant to these snake venoms and has natural venom inhibitors in its plasma. The aim of this work was to clone and study the chemical, physicochemical and biological properties of DM64, an antimyotoxic protein from opossum serum. DM64 is an acidic protein showing 15% glycosylation and with a molecular mass of 63 659 Da when analysed by MALDI‐TOF MS. It was cloned and the amino acid sequence was found to be homologous to DM43, a metalloproteinase inhibitor from D. marsupialis serum, and to human α 1 B‐glycoprotein, indicating the presence of five immunoglobulin‐like domains. DM64 neutralized both the in vivo myotoxicity and the in vitro cytotoxicity of myotoxins I (mt‐I/Asp49) and II (mt‐II/Lys49) from Bothrops asper venom. The inhibitor formed noncovalent complexes with both toxins, but did not inhibit the PLA 2 activity of mt‐I. Accordingly, DM64 did not neutralize the anticoagulant effect of mt‐I nor its intracerebroventricular lethality, effects that depend on its enzymatic activity, and which demonstrate the dissociation between the catalytic and toxic activities of this Asp49 myotoxic PLA 2 . Furthermore, despite its similarity with metalloproteinase inhibitors, DM64 presented no antihemorrhagic activity against Bothrops jararaca or Bothrops asper crude venoms, and did not inhibit the fibrinogenolytic activity of jararhagin or bothrolysin. This is the first report of a myotoxin inhibitor with an immunoglobulin‐like structure isolated and characterized from animal blood.