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Published on: January 26, 2018
Regiochemical and stereochemical evidence for enzyme-initiated catalysis in dual positional specific maize
Sungkuk Jang1, Thavrak Huon, Keumhwa Kim
1Department of Molecular Biotechnology, Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, Kwangju 500-757, Republic of Korea.
Abstract:
Dual positional specific maize lipoxygenase-1 catalyzed the formation of racemic mixtures of four possible regioisomers and was strongly inhibited by the radical scavenger, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinoxy radical. Molecular modeling studies indicated that the oxygen-binding cavity is segregated from the substrate-binding cavity. The data suggest that a bis-allylic radical reaction intermediate is generated enzymatically, released from the enzyme active site, and subsequently oxygenated outside of the enzyme active site by a nonenzymatic mechanism.
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