Studelska D R, Campbell N R, Brimijoin W S
Life Sci. 1985 Mar 4;36(9):881-7. doi: 10.1016/0024-3205(85)90212-7.
Norepinephrine (NE) binds extensively to protein that copurifies with phenylethanolamine-N-methyltransferase (PNMT) prepared from bovine adrenal medulla. This binding interferes with a NE assay that employs PNMT to catalyze the transfer of a tritiated methyl group from S-adenosyl-L-methionine to the amine group of NE. It was discovered that the protein binding of endogenous NE is reversed by dialysis at pH 6.0. Preparations of PNMT intended for use in radioenzymatic assays should involve one or more purification steps at pH 6.0.
去甲肾上腺素（NE）与从牛肾上腺髓质制备的苯乙醇胺-N-甲基转移酶（PNMT）共纯化的蛋白质广泛结合。这种结合干扰了一种NE测定方法，该方法利用PNMT催化氚标记的甲基从S-腺苷-L-甲硫氨酸转移到NE的胺基上。研究发现，内源性NE的蛋白质结合在pH 6.0时通过透析可以逆转。用于放射性酶测定的PNMT制剂应在pH 6.0下进行一个或多个纯化步骤。
