Phosphatidylethanolamine, cytochrome

Cleavage of the oxirane C-0 bond produces a zwitterionic intermediate (Fig. 10.22), which that can undergo chloride shift (Pathway a) to 2,2-dich-loroacetyl chloride (10.90) followed by hydrolysis to 2,2-dichloroacetic acid (10.91). Furthermore, the zwitterionic intermediate reacts with H20 or H30+ (Pathway b) by pH-independent or a H30+-dependent hydrolysis, respectively. The pH-independent pathway only is shown in Fig. 10.22, Pathway b, but the mechanism of the H30+-dependent hydrolysis is comparable. Hydration and loss of Cl, thus, leads to glyoxylyl chloride (10.92), a reactive acyl chloride that is detoxified by H20 to glyoxylic acid (10.93), breaks down to formic acid and carbon monoxide, or reacts with lysine residues to form adducts with proteins and cytochrome P450 [157], There is also evidence for reaction with phosphatidylethanolamine in the membrane. 

Figure 1. Control of mitochondrial biogenesis by the nuclear genome. Most mitochondrial proteins, including cytochrome c, are nuclear gene products which are subsequently imported into mitochondria. Similarly, most enzymes involved in synthesis of mitochondrial phosphoplipids are encoded in the nuclear genome. Being located in the endoplasmatic reticulum, they synthesize phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), phosphatidylglycerol (PG) and phosphatidylinositol (Ptdins). The phospholipids are transferred to the outer membrane. The imported lipids then move into the inner membrane at contact sites. Mitochondria then diversify phospholipids. They decarboxylate phosphatidylserine to phosphatidylethanolamine (PtdEtN), but the main reaction is the conversion of imported phosphatidylglycerol to cardiolipin (CL). Cardiolipins localize mainly in the outer leaflet of the inner membrane.

Fig. 1. Targeted lipidomics of anandamide metabolism. Postulated pathways of anandamide metabolism. Abbreviations PC, phosphatidylcholine PE, phosphatidylethanolamine NAT, JV-acyl transferase LPA, lysophosphatidic acid PA, phosphatidic acid NAPE, jV-acyl-phosphatidylethanolamine Lyso-NAPE, l-lyso,2-acyl-OT-glycero-3-phosphoethanolamine-JV-acyl ABHD-4, a//3 hydrolase-4 GP-anandamide, glycerophospho-anandamide PAEA, phospho-anandamide PLA, phospholipase A NAPE-PLD, NAPE phospholipase D PLC, phospholipase C FAAH, fatty acid amide hydrolase P, phosphatase COX, cyclooxygenase LOX, lipoxygenase CYP450, cytochrome P450 PDE, phosphodiesterase.

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