Phosphatidylcholine Synthesis in Agrobacterium tumefaciens
Year: 1964
Type: article
Abstract: methyl groups of S-adenosyl-L-methionine into three methylated lipids: phosphatidyl-N-methylethanolamine, phosphatidyl-l\r,Ndimethylethanolamine, and phosphatidylcholine.Of the three possible substrates, only exogenous phosphatidyl-N-methylethanolamine ( 7) and phosphatidyl-iV ,N-dimethylethanolamine(2) increased transmethylation.Phosphatidylethanolamine was ineffective in this respect.While phosphatidylcholine is the most abundant phospholipid in many plant and animal tissues, it is a rare component of bacterial lipids (8-10).Bacteria of the genus Agrobacterium, however, utilize the methyl group of methionine as a source of the methyl groups of phosphatidylcholine and other N-methylated phospholipids (9, lo), while Clostridium butyricum produces phosphatidyl-N-methylethanolamine, but no phosphatidylcholine (11).In this paper the synthesis of phosphatidyl-Nmethylethanolamine, phosphatidyl-2\i,N-dimethylethanolamine, and phosphatidylcholine by means of transmethylation reactions is demonstrated in extracts of Agrobacterium tumejaciens.A phosphatidylethanolamine N-methyltransferase that requires an exogenous source of phosphatidylethanolamine has been partially purified and characterized. EXPERIMENTAL PROCEDURE MaterialsPhospholipids-All commercial phospholipids purchased from Mann Research Laboratories and Light and Company (Colnbrook, Bucks, England) were examined by thin layer chromatography and found to be inhomogeneous, but the major components were those claimed by the vendor.nn-a-Dihexanoyl-and nn-cr-didecanoylphosphatidylethanolamines were gifts of Dr. J. Maurukas (12).Adenosylmethionine-Unlabeled S-adenosyl-L-methionine was prepared by the procedure of Schlenk, Dainko, and Stanford (13).AMel labeled with 14C in the methyl group (13.78 PC per pmole), purchased from Tracerlab, Inc., was diluted with 0.1 M potassium acetate, pH 5.0, and stored at -20".Reagents-Sulfhydryl compounds and inhibitory reagents were commercial samples, many of which were generously supplied by
Source: Journal of Biological Chemistry
Authors: Tsuneo Kaneshiro, John H. Law
Institution: Harvard University
Language: English
Subfield: Biochemistry
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W65795780