Isolation and structural characterization of a cytotoxic L-amino acid oxidase from Agkistrodon contortrix laticinctus snake venom: Preliminary crystallographic data
Dhf. Souza et al., Isolation and structural characterization of a cytotoxic L-amino acid oxidase from Agkistrodon contortrix laticinctus snake venom: Preliminary crystallographic data, ARCH BIOCH, 368(2), 1999, pp. 285-290
We have purified a cytotoxic L-amino acid oxidase (LAO) from Agkistrodon co
ntortrix laticinctus snake venom by means of Superdex-200 gel filtration, f
ollowed by phenyl-Sepharose CL-4B chromatography, The purified enzyme (ACL
LAO) is a dimer on gel filtration, with a M-r of 60,000 for the monomer as
estimated by SDS-PAGE. LAO activity was tested against 15 amino acids, but
only 9 were oxidized by the enzyme, suggesting that it presents some degree
of specificity. ACL LAO has apoptosis-inducing activity in an HL-60 cell c
ulture assay. After 24 h treatment with 25 mu g/ml of ACL LAO, the typical
DNA fragmentation pattern of apoptotic cells was observed on agarose gel el
ectrophoresis. NMR analysis showed the presence of a flavin mononucleotide
prosthetic group. To solve its 3-D structure, crystals of the purified prot
ein were grown in 0.1 M Tris-HCl, pH 8.5, and 2 M (NH4)(2)SO4. Diffraction
data collected to 3.5 Angstrom showed that the protein crystallized in the
tetragonal system, with unit cell a = b = 103.22 Angstrom, c = 183.45 Angst
rom. This is the first report of preliminary crystallization data for a sna
ke venom L-amino acid oxidase. (C) 1999 Academic Press.