Purification,
Characterization and Biological Activity of an L-Amino Acid Oxidase from
Trimeresurus mucrosquamatus Venom
WEI Ji-Fu1,2, WEI
Qin1, LU Qiu-Min1, TAI Hong1, JIN Yang1,
WANG Wan Yu1, XIONG Yu-Liang1*
( 1Department of Animal Toxicology, Kunming Institute
of Zoology, the Chinese Academy of Sciences, Kunming 650223, China;
2The Graduate School of the Chinese Academy of Sciences, Beijing
100039, China )
Abstract An L-amino acid oxidase (TM-LAO) from the
venom of Hunan Trimeresurus mucrosquamatus was purified to homogeneity
by three steps including DEAE Sephadex A-50 ion-exchange chromatography,
Sephadex G-75 gel filtration and Resourse Q ion-exchange chromatography. TM-LAO
is composed of two identical subunits with a molecular weight of 55 kD by SDS-polyacrylamide
gel electrophoresis. The molecular weight was different with that of LAO
purified from the same species distributed in Taiwan that was 70 kD. The 24
N-terminal amino acid sequence of TM-LAO is ADNKNPLEECFRETNYEEFLEIAR, which
shares high similarity with other Viperid snake venom LAOs and has moderate
similarity with Elapid snake venom LAOs. Further studies found that TM-LAO
inhibited the growth of E. coli, S. aurues and B. dysenteriae.
TM-LAO also showed cytotoxicity and platelet aggregation activity. All the
biological activities were eliminated by catalase, a H
scavenger. It shows that these biological effects are possibly due to the
formation of H
TM-LAO.
Key
words L-amino acid oxidase; Trimeresurus
mucrosquamatus; antibacterial activity; cytotoxicity; platelet aggregation
Corresponding
author: Tel,86-871-5192476;
Fax, 86-871-5191823; e-mail, [email protected]