Tetrahydropteridine-dependent cleavage enzyme for O-alkyl lipids: substrate specificity

Abstract The tetrahydropteridine-requiring enzyme in rat liver microsomes that oxidatively cleaved the O -alkyl moiety of glycerolipids does not utilize alkyl glycerolipid substrates that contain carbonyl, acyl, or phosphate groups on the glycerol portion. However, the ether linkage in rac and 1-, 2-, or 3-isomeric forms of alkylglycerols and 1-alkyl- sn -glycero-3-phosphorylethanolamine is readily cleaved by the pteridine-requiring enzyme. Therefore, it appears that hydrolytic enzymes play an essential role in conjunction with the cleavage enzyme in the regulation of cellular levels of O -alkyl moieties in glycerolipids.