Biochemical and functional properties of a new L-amino acid oxidase (LAAO) from Micrurus lemniscatus snake venom.
This study reports the purification of ML-LAAO, a new LAAO from the venom of Micrurus lemniscatus snake (ML-V), using size exclusion chromatography. ML-LAAO is a 69-kDa glycoprotein that represents ∼ 2.0 % of total venom proteins. This enzyme exhibited optimal activity at pH 8.5, displaying high specificity toward hydrophobic L-amino acids. MALDI TOF/TOF and Blast analysis identified internal segments in ML-LAAO that share high sequence identity with homologous snake venom LAAOs. Western blot analysis on two-dimensional SDS-PAGE of ML-V using anti-LAAO revealed the presence of ML-LAAO isoforms (pI 6.3 - 8.9). ML-LAAO blocked aggregation induced by collagen on washed platelets in a rather weak manner, it did not, however, inhibit platelet aggregation induced by ADP on platelet-rich plasma. In addition, this enzyme displayed in vitro antibacterial activity against Staphylococcus aureus (MIC/MBC of 0.39 μg/mL) and in vitro leishmanicidal action against Leishmania amazonensis and L. chagasi (IC50 values of 0.14 and 0.039 μg/mL, respectively). These activities were significantly reduced by catalase, suggesting that hydrogen peroxide production is involved in some way. The data presented here revealed that ML-LAAO has bactericidal and leishmanicidal effects, suggesting that it may have therapeutic potential.
PMID: 31759013 [PubMed - as supplied by publisher]
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Geraldo Soares T, Dos Santos JL, Gonçalves de Alvarenga V, Soares Coelho Santos J, Yvette Leclercq S, Dolores Faria C, Aparecida Assunção Oliveira M, Porto Bemquerer M, Oswaldo Flores Sanchez E, Elena de Lima M, Gomes Figueiredo S, Helena Borges M Tags: Int J Biol Macromol Source Type: research