title: A diffusion assay for detection and quantitation of methyl-esterified proteins on polyacrylamide gels.
abstract: The methyl esterification of bacterial and mammalian proteins is a subject of increasing interest and effort. Such studies in intact cells typically involve the use of [methyl-3H]methionine which is taken up and incorporated into S-adenosyl-L-methionine, the methyl donor. The level of methylation, however, is much less than the incorporation of labeled methionine directly into protein. A diffusion assay which distinguishes [3H]methionine from the base-labile [3H]methyl esters is described here. The ester linkage is hydrolyzed at high pH to release [3H]methanol from the sample which diffuses into an adjacent pool of scintillation fluid. The assay is contained in a scintillation vial which can be counted directly.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D004058:Diffusion; D004591:Electrophoresis, Polyacrylamide Gel; D004951:Esterification; D006868:Hydrolysis; D000432:Methanol / Q000032:analysis; D008715:Methionine / Q000378:metabolism; D008745:Methylation; D011506:Proteins / Q000032:analysis*; D012486:Salmonella typhimurium / Q000032:analysis; D014316:Tritium
chemical_list: D001426:Bacterial Proteins; D011506:Proteins; D014316:Tritium; D008715:Methionine; D000432:Methanol