North Pacific krill (Euphausia pacifica) contain 8R-hydroxy-eicosapentaenoic acid (8R-HEPE), 8R-hydroxy-eicosatetraenoic acid (8R-HETE) and 10R-hydroxy-docosahexaenoic acid (10R-HDHA). These findings indicate that E. pacifica must possess an R type lipoxygenase, although no such enzyme has been identified in krill. We analyzed E. pacifica cDNA sequence using next generation sequencing and identified two lipoxygenase genes (PK-LOX1 and 2). PK-LOX1 and PK-LOX2 encode proteins of 691 and 686 amino acids, respectively. Recombinant PK-LOX1 was generated in Sf9 cells using a baculovirus expression system. PK-LOX1 metabolizes eicosapentaenoic acid (EPA) to 8R-HEPE, arachidonic acid (ARA) to 8R-HETE and docosahexaenoic acid (DHA) to 10R-HDHA. Moreover, PK-LOX1 had higher activity for EPA than ARA and DHA. In addition, PK-LOX1 also metabolizes 17S-HDHA to 10R,17S-dihydroxy-docosahexaenoic acid (10R,17S-DiHDHA). PK-LOX1 is a novel lipoxygenase that acts as an 8R-lipoxygenase for EPA and 10R-lipoxygenase for DHA and 17S-HDHA. Our findings show PK-LOX1 facilitates the enzymatic production of hydroxy fatty acids, which are of value to the healthcare sector.

北太平洋磷虾（Euphausia pacifica）含有8 R-羟基二十碳五烯酸（8 R -HEPE），8 R-羟基二十碳四烯酸（8 R -HETE）和10 R-羟基二十二碳六烯酸（10 R -HDHA）。这些发现表明，尽管在磷虾中还没有发现这种酶，但太平洋大肠杆菌必须具有R型脂氧合酶。我们使用下一代测序方法分析了大肠杆菌的cDNA序列，并鉴定了两个脂氧合酶基因（PK-LOX1和2）。PK-LOX1和PK-LOX2分别编码691和686个氨基酸的蛋白质。使用杆状病毒表达系统在Sf9细胞中产生了重组PK-LOX1。PK-LOX1将二十碳五烯酸（EPA）代谢为8 R -HEPE，将花生四烯酸（ARA）代谢为8 R -HETE，将二十二碳六烯酸（DHA）代谢为10 R -HDHA。此外，PK-LOX1对EPA的活性高于ARA和DHA。另外，PK-LOX1还将17 S -HDHA代谢为10 R，17 S-二羟基-二十二碳六烯酸（10 R，17 S -DiHDHA）。PK-LOX1是一种新型脂加氧酶，对于EPA而言，它充当8 R-脂加氧酶；对于DHA和17 S，它充当10 R-脂加氧酶。-HDHA。我们的研究结果表明PK-LOX1促进了羟基脂肪酸的酶促生产，这对医疗保健领域具有重要意义。