Ethanolamine headgroup

The phospholipid monolayers examined in this study were all saturated, symmetric, 1,2-diacyl-j -glycero-3-phosphate-based lipids. Four different lipid headgroups attached to the phosphate were examined choline, ethanolamine, glycerol and serine. Each lipid features a glycerol backbone, two saturated fatty acid chains and a phosphatidyl headgroup. 

The total synthesis of a novel hybrid lipid Pea-PIP2 (51), possessing a phosphatidyl ethanolamine (PE) headgroup at the 1-position and a phosphatidyl inositol 4,5-bisphosphate [PtdIns(4,5)P2] headgroup at the 4-position has been elaborated. Reporter groups (biotin, fluorophores, spin label) were... 

The nucleotide pathway is the major pathway of phosphatidylethanolamine (PE) headgroup biosynthesis by plants (Sparace, et aL, 1981). It is catalyzed in sequence by ethanolamine kinase (EK), ethanolaminephosphate cytidylyltransferase (ECT) and ethanolamine phosphotransferase (EPT). EK has been characterized and purified from spinach leaves (Macher and Mudd, 1976) and soybean seeds (Williams and Harwood, 1994), EPT has been characterized in several plants (10), but little information is available about ECT. The only plant tissue in which ECT has been characterized is castor bean endosperm, where approximately 80% of the activity is in the outer mitochondrial membrane and the remainder in the endoplasmic reticulum (ER Wang and Moore, 1991). ECT is soluble in mammals and yeast (Sundler, 1975). 

ECT of the ER probably regulates PE headgroup biosynthesis by the nucleotide pathway. This is supported by its activity throughout development being consistent lower than the other key enzymes, and the Km being higher than those for either EK or EPT. This suggests abundant production of ethanolamine-P and ready use of any CDPethanolamine produced. 

The quadrupolar splitting, Avq, of headgroup-deuterated PC or PE varies linearly as a function of the total amount of electric surface charge, and changes in opposite direchons are induced by positive and negative surface charges. This indicates that the phosphocholine and the phospho-ethanolamine dipoles are sensitive to electric charges at the membrane surface and function as an electrometer. As an example, the interaction of a-CD2-POPC with an anionic and a cationic amphiphile is shown in Eig. 3. 

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