ISOLATION, PURIFICATION AND SOME PROPERTIES - Biochemistry and Biotechnology: Research and Development - page 15

C ONCLUSION

L-Lysine α-oxidase (LO) presents one of the enzymes which are perspective for
antitumor enzyme therapy. Its biological action is based on the depletion of essential amino
acid L-lysine. During the cultivation on solid substrate (soaked wheat bran) of 12 different
strains belonging to the genus Trichodermа the most intensive LO biosynthesis was observed
with Trichodermа. sp . 6 . The optimal fermentation conditions in laboratory bioreactors were
elaborated (рО 2 , рН, nitrogen sources and temperature), and it lead to the enhancement of LO
biosynthesis up to 170 U/g of wheat bran. The analysis of literature data points that so high
level of LO enzymatic activity was not observed beforehand. New effective technique of LO
isolation and purification was developed and homogeneous enzyme preparation was obtained
with specific activity 99 U/mg protein (25 o C). Molecular weight of enzyme determined by
native electrophoreses and gel filtration was equal to 115-116 кDа. According to SDS
electrophoresis data LO is a dimeric molecule with identical subunits of 57-58 kDa. Optical
absorption spectrum of LO are analogous to those of flavoproteins with maximums at 278,
390 and 465 nm (shoulder at 490 nm). The prosthetic group of the enzyme proved to be FAD
and each subunit possesses one molecule of FAD.
LO is a stereo specific enzyme oxidizing only L-lysine (pH optimum 7.8 - 8.0),
insignificant activity towards L-ornithine and L-arginine was observed. High termal stability
of LO was shown: the enzyme retained its activity up to 50 ºC. LO from a new strain
producer exhibited cytotoxic, antibacterial and antifungal activity.

R EFERENCES

[1] Т.Т. Berezov: Biomedical Chemistry , №3, 235(2005).
[2] E.V.Lukasheva, H.M.Treshalina, T.T.Berezov: in: Biotechnology in Biology and

Medicine Retail, Editors: A.M. Egorov and G. Zaikov, N.-Y, Nova Science
Publishers.,INC., 205 (2006).

[3] H.Kusakabe, K.Kodama, H. Machida, A. Kuninaka : Agric. Biol. Chem ., 43, 337(1979).

[4] H.M.Treshalina, L.A.Sedakova, G.A.Firsova, G.K.Guerassimova, N.V. Gogichaeva,

E.V.Lukasheva, Т.Т.Berezov: Applied Biochem. Biotechnol ., 84, 267(2000).

[5] T.T.Berezov, E.V.Lukasheva: Biochemistry International , l7(3), 529(1988).

[6] L.A. Osterman: Methods for studying proteins and nucleic acids. Electrophoresis and

ultracentrifugation. Ed. Science , 59(1981).

[7] I.P. Smirnova, Т.Т. Berezov: Microbiology, 56,708(1987).

[8] H.Kusakabe, K.Kodama , A.Kuninaka, H.Yoshino, K.Soda: Agric.Biol.Chem .,43(12),

2531(1979).

[9] H.Kusakabe, K.Kodama , A.Kuninaka, H.Yoshino, K.Soda: J. Biol. Chem ., 255, 976

(1980).