title: Molecular cloning and biochemical characterization of a myotoxin inhibitor from Bothrops alternatus snake plasma.
abstract: Phospholipases A(2) (PLA(2)s) are important components of Bothrops snake venoms, that can induce several effects on envenomations such as myotoxicity, inhibition or induction of platelet aggregation and edema. It is known that venomous and non-venomous snakes present PLA(2) inhibitory proteins (PLIs) in their blood plasma. An inhibitory protein that neutralizes the enzymatic and toxic activities of several PLA(2)s from Bothrops venoms was isolated from Bothrops alternatus snake plasma by affinity chromatography using the immobilized myotoxin BthTX-I on CNBr-activated Sepharose. Biochemical characterization of this inhibitory protein, denominated αBaltMIP, showed it to be a glycoprotein with Mr of ~24,000 for the monomeric subunit. CD spectra of the PLA(2)/inhibitor complexes are considerably different from those corresponding to the individual proteins and data deconvolution suggests that the complexes had a relative gain of helical structure elements in comparison to the individual protomers, which may indicate a more compact structure upon complexation. Theoretical and experimental structural studies performed in order to obtain insights into the structural features of αBaltMIP indicated that this molecule may potentially trimerize in solution, thus strengthening the hypothesis previously raised by other authors about snake PLIs oligomerization.
authors.affiliation: Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, FMRP-USP, Ribeirão Preto-SP, Brazil. norival@fcfrp.usp.br
authors.forename: Norival A
authors.initials: NA
authors.lastname: Santos-Filho
authors.forename: Carlos A H
authors.initials: CA
authors.lastname: Fernandes
authors.forename: Danilo L
authors.initials: DL
authors.lastname: Menaldo
authors.forename: Angelo J
authors.initials: AJ
authors.lastname: Magro
authors.forename: Consuelo L
authors.initials: CL
authors.lastname: Fortes-Dias
authors.forename: Maria Inácia
authors.initials: MI
authors.lastname: Estevão-Costa
authors.forename: Marcos R M
authors.initials: MR
authors.lastname: Fontes
authors.forename: Camila R
authors.initials: CR
authors.lastname: Santos
authors.forename: Mário T
authors.initials: MT
authors.lastname: Murakami
authors.forename: Andreimar M
authors.initials: AM
authors.lastname: Soares
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001798:Blood Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology*; D017837:Bothrops / Q000097:blood* / Q000235:genetics; D002460:Cell Line; D003001:Cloning, Molecular; D006801:Humans; D051379:Mice; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D064801:Phospholipase A2 Inhibitors; D017433:Protein Structure, Secondary
chemical_list: D001798:Blood Proteins; C400481:PLIalpha; D064801:Phospholipase A2 Inhibitors