CL(18:1(8Z)/16:1(8Z)/18:1(8Z)/20:4(5Z,8Z,11Z,14Z)) is a cardiolipin (CL). Cardiolipins are sometimes called a 'double' phospholipid because they have four fatty acid tails, instead of the usual two. CL(18:1(8Z)/16:1(8Z)/18:1(8Z)/20:4(5Z,8Z,11Z,14Z)) contains two chains of (13Z-octadecenoyl) at the C1 and C3 positions, one chain of (8Z-hexadecenoyl) at the C2 position, one chain of (5Z,8Z,11Z,14Z-eicosatetraenoyl) at the C4 position. While the theoretical charge of cardiolipins is -2, under normal physiological conditions (pH near 7), the molecule may carry only one negative charge. In prokaryotes such as E. coli, the enzyme known as diphosphatidylglycerol synthase catalyses the transfer of the phosphatidyl moiety of one phosphatidylglycerol to the free 3'-hydroxyl group of another, with the elimination of one molecule of glycerol. In E. coli, which acylates its glycerophospholipids with acyl chains ranging in length from 12 to 18 carbons and possibly containing an unsaturation, or a cyclopropane group more than 100 possible CL molecular species are theoretically possible, 53 of these species having been characterized. E. coli membranes consist of ~5% cardiolipin (CL), 20-25% phosphatidylglycerol (PG), and 70-80% phosphatidylethanolamine (PE) as well as smaller amounts of phosphatidylserine (PS). CL is distributed between the two leaflets of the bilayers and is located preferentially at the poles and septa in E. coli and other rod-shaped bacteria. It is known that the polar positioning of the proline transporter ProP and the mechanosensitive ion channel MscS in E. coli is dependent on CL. It is believed that cell shape may influence the localization of CL and the localization of certain membrane proteins.
Belongs to the class of organic compounds known as glycerophosphoglycerophosphoglycerols. These are glycerophospholipids that contain three glycerol moieties sequentially linked to each other with a phosphate group. They include cardiolipins.
