Lipoxygenase biocatalysis: a survey of asymmetric oxygenation

Lipoxygenases are a group of non-heme iron containing dioxygenases catalyzing the addition of molecular oxygen to poly unsaturated fatty acids in a stereospecific as well as regiospecific way and involved in the biosynthesis of inflammatory mediators, in cell differentiation and atherogenesis. Synthetic use of lipoxygenase over the last decade for total synthesis of several natural products, e.g. 6(R)-lopoxin A, 5(S)-HPETE, (R) and (S) coriolide is discussed in this review. In the second part of the review we have discussed on the LOX biocatalysis of unnatural substrates mimicking natural substrates, lipoxygenase biocatalysis in non-conventional media, the use of immobilized LOX and biocatalysis with engineered lipoxygenase. The factors governing the regiospecificity as well as stereospecificity of LOX biocatalysis will also be discussed here. From the synthetic chemist’s point of view, the asymmetric oxygenation reaction of unnatural substrates has a tremendous potential. The products of these reactions are important chiral building blocks for the total synthesis of numerous biological active natural products.

Source: Journal of Molecular Catalysis B: Enzymatic (2003) vol. 26, p. 3-28

A New 9-Lipoxygenase cDNA from Developing Rice Seeds

We isolated a novel C9 position specific lipoxygenase (r9-LOX1) cDNA from developing rice seeds. The enzymatic features of r9-LOX1 resembled those of rice LOX-L3 known to be contained in rice germ and to have C9-specific LOX activity. However, the expression level of the r9-LOX1 gene was higher in imbibed seeds rather than developing seeds. A homology search against the rice nucleotide database revealed the r9-LOX1 gene to be on rice chromosome 3 (accession number AC093017). The restriction enzyme map of the reported genomic sequence agreed with the result of the Southern blot analysis for the r9-LOX1. The enzyme could be useful for in vitro synthesis of 9,10-ketol-octadecadienoic acid.

Source: Plant and Cell Physiology (2003) vol. 44, p. 1168-1175