Eriksson S, Larsson C
Biochim Biophys Acta. 1976 Aug 12;445(1):67-73. doi: 10.1016/0005-2744(76)90160-1.
alpha 1-Antitrypsin phenotypes Pi M and Z, purified by the thiol-disulfide exchange procedure, were desialylated by treatment with neuraminidase covalently coupled to Sepharose and used as acceptors of sialic acid in an assay system for serum sialic acid transferase (CMP-N-acetylneuraminate:D-galactosyl-glycoprotein N-acetylneuraminyltransferase, EC 2.4.99.1) activity. Both asialoantitrypsins were equally effective as acceptors in contrast to native Pi Z antitrypsin which did not accept any sialic acid. Serum sialyltransferase activity was determined in 38 adult alpha 1-antitrypsin deficient individuals (Pi Z, MZ, FZ, SZ) with normal liver function and was found to be of the same magnitude as the activity in normal individuals (Pi M). Equal activities were also found in 5 Pi Z patients with cirrhosis of the liver. The results strongly argue against the concept that sialyltransferase deficiency provides the molecular basis for alpha 1-antitrypsin deficiency.
通过硫醇 - 二硫键交换程序纯化的α1 - 抗胰蛋白酶表型Pi M和Z，经与琼脂糖共价偶联的神经氨酸酶处理后进行去唾液酸化，并用作血清唾液酸转移酶（CMP - N - 乙酰神经氨酸：D - 半乳糖基 - 糖蛋白N - 乙酰神经氨酸基转移酶，EC 2.4.99.1）活性测定系统中唾液酸的受体。与不接受任何唾液酸的天然Pi Z抗胰蛋白酶相反，两种去唾液酸抗胰蛋白酶作为受体的效果相同。在38名肝功能正常的成年α1 - 抗胰蛋白酶缺乏个体（Pi Z、MZ、FZ、SZ）中测定了血清唾液酸转移酶活性，发现其活性与正常个体（Pi M）的活性大小相同。在5名肝硬化的Pi Z患者中也发现了相同的活性。结果有力地反驳了唾液酸转移酶缺乏是α1 - 抗胰蛋白酶缺乏分子基础的观点。
