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Characterization of the lipoxygenase activity associated with lectin from Dolichos biflorus
Author(s) -
Subbaiah Roopashree,
Singh Sridevi Annapurna,
Gowda Lalitha R.,
Rao Appu A. G.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a474-c
Subject(s) - lectin , lipoxygenase , chemistry , biochemistry , dimer , enzyme , organic chemistry
The D. biflorus lectin is a tetrameric glycoprotein with a molecular mass of 110,000 and consists of two unidentical subunits, I and II with six manganese atoms. We have characterized the lipoxygenase activity associated with the lectin from D. biflorus . The lipoxygenase activity associated with lectin had an acidic pH optimum and high thermal stability. Substrate preference, regio and stereospecificity of the products generated thereof, revealed that the activity was similar to iron dependent plant lipoxygenases. The protein had characteristics similar to other lipoxygenases for cooxidation of β ‐carotene and was inhibited by ETYA and NDGA. 4‐ nitrocatechol did not inhibit the activity. The tetrameric lectin contains a hydrophobic site per dimer. Lipoxygenase activity of lectin was inhibited by ANS in competitive way. The presence of Mn 2+ in the lectin molecule may allow it to function as a lipoxygenase molecule. The separated subunits did not have any lipoxygenase activity. This is the first (novel) report of a lectin having LOX activity, which may probably help explain the indomitable pest resistance enjoyed by this unusual legume.