Biosynthesis of 12(R)-HETE in invertebrates is via lipoxygenation of arachidonic acid . In mammals, 12(R)-HETE can be produced by 12(R)-LOs and also by CYP450 oxidation. The activity of 12(R)-HETE in mammals is predominantly proinflammatory. 12(R)-HETE exhibits dose-dependent leukocyte chemotaxis at concentrations as low as 100 nM, and lowers intraocular pressure in rabbits.
Ceramide phosphoethanolamine (CPE) is an analog of sphingomyelin that contains ethanolamine rather than choline as the head group. It is the principal membrane phospholipid in invertebrates such as Drosophila, which lacks sphingomyelin. It is only produced in small amounts in mammalian cells, accounting for approximately 0.02 mol% of total phospholipids in mouse testis and brain. In Drosophila, CPE is biosynthesized by CPE synthase from ceramide and cytidine diphosphate-ethanolamine in the Golgi lumen. In mammals, it is biosynthesized by sphingomyelin synthase 2 (SMS2) in the plasma membrane and by sphingomyelin synthase-related protein (SMSr) in the endoplasmic reticulum (ER). In Drosophila, CPE has a role in glial ensheathment of axons. Disrupting CPE synthesis by depleting SMSr in vitro in mammalian cells leads to an accumulation of ER ceramides, which are then mislocalized to the mitochondria, inducing apoptosis. However, ceramide levels are not altered in transgenic mice lacking SMSr catalytic activity. CPEs (bovine) is a mixture of CPEs with variable N-acyl chain lengths.
8(R)-HETE is biosynthesized by lipoxygenation of arachidonic acid in marine invertebrates such as gorgonian corals and starfish. Stereochemical assignment of the (R) enantiomer is based on comparison of chiral HPLC retention times to published results.
Phospho-L-arginine is a phosphorylated form of L-arginine and a highly diffusible, high-energy metabolite and phosphagen involved in energy storage in invertebrates including crustaceans, insects, and Trypanosoma species. In the locust L. migratoria, phospho-L-arginine is found in the flight muscles, where it acts as both a buffer system and shuttle mechanism for high-energy phosphate. Measurement of phospho-L-arginine by 31P-NMR spectroscopy has been used to study invertebrate energy metabolism in vivo.
Ferritin is a protein of 450 kDa consisting of 24 subunits that is present in every cell type. Invertebrates, these subunits are both the light (L) and the heavy (H) type with an apparent molecular weight of 19 kDA or 21 kDA respectively. The ferritin fou