The acyl and Alk‐1‐enyl groups of the major phosphoglycerides from ox brain myelin and mouse brain microsomal, mitochondrial and myelin fractions

Abstract

The major phosphoglycerides from ox brain myelin and mouse brain microsomal, mitochondrial and myelin fractions were separated by preparative thin layer chromatography. Alk-l-enyl groups from the alk-1 -enyl acyl gly c er o p hosphorylethanolamines were reacted with 1,3-propanediol to form the 1,3-dioxolane derivatives. Acyl groups were converted to the methyl ester derivatives and the acyl groups from alk-1enyl acyl glycerophosphorylethanolamines and diacyl glycerophosphorylethanolamines were also determined separately. The acyl and alk-l-enyl group compositions of the phosphoglycerides from microsomal and mitochondrial fractions were quite similar. The ethanolamine and serine phosphoglycerides contained large amounts of 18:0, 18:1, 20:4 and 22:6 acyl groups. The choline phosphoglycerides had small amounts of polyunsaturated acyl groups and large amounts of 16:0, 18:1 and 18:0 acyl groups. The mitochondrial cardiolipins contained unusual amounts of several acyl groups including 18: 1, 52%; 18:2, 6%; and 16.1, 4%. A large portion of the mouse brain 18:2 is in that fraction. The myelin phosphoglycerides were deficient in saturated and 22:6 groups and markedly enriched in 18:1 and 20" 1 groups when compared with the corresponding microsomal or mitochondrial phosphoglycerides.

Phospholipase A2 in the central nervous system

“…Phospholipids in CNS membranes are enriched in polyunsaturated fatty acids (PUFAs) (2). Metabolism of PUFA is stringently controlled by phospholipase A 2 (PLA 2 ) and acyltransferases-known as the "deacylation-reacylation cycle" (3)(4)(5).…”

“…To date, limited information is available on the structure and functions of acyltransferases. However, recent advances in molecular biological techniques have aided in the identification of many genes encoding different groups of PLA 2 and have provided new information on the properties and functions of these molecules.…”

“…The authors plan to update the information in this site periodically. PLA 2 cPLA 2 cPLA 2 belongs to the group IV PLA 2 s. Although three isoforms, i.e., cPLA 2 ␣ , -␤ , and -␥ , have been identified, the 85 kDa cPLA 2 ␣ has been studied most extensively. This protein is comprised of a C2 domain and multiple phosphorylation sites, including two consensus sites (S505 and S727) for phosphorylation by mitogen-activated protein kinases (MAPKs) (12) and an S515 site for Ca 2 ϩ /calmodulin (9).…”

“…This protein is comprised of a C2 domain and multiple phosphorylation sites, including two consensus sites (S505 and S727) for phosphorylation by mitogen-activated protein kinases (MAPKs) (12) and an S515 site for Ca 2 ϩ /calmodulin (9). The C2 domain confers a Ca 2 ϩ -dependent translocation mechanism for this cPLA 2 (14,15). Recent studies have provided evidence for translocation of cPLA 2 from the cytosol to nuclear membranes (16).…”

“…PLA 2 ␣ seems to prefer hydrolysis of AA from phosphatidylcholine (9). In macrophages, as well as in other cell systems, agents including G protein-coupled receptor agonists, calcium ionophores, phorbol esters, and zymogens can activate cPLA 2 , resulting in AA release (12). Through its linkage to receptor-mediated signaling pathways, cPLA 2 is an important PLA 2 for rapid AA release in cells and for modulating a number of intracellular processes.…”