Bolmer S, Kleinerman J
Am J Pathol. 1986 May;123(2):377-89.
Chronic galactosamine (GalNH2) administration in rats decreases plasma alpha 1-antitrypsin (AAT) levels to 10-50% of control levels and induces the formation of diastase-resistant, PAS-positive granules, which contain AAT in hepatocytes. This report describes the isolation and purification of hepatic granule AAT by three different methods: solubilization with guanidine hydrochloride followed by gel filtration on Bio-gel A5M, extraction with methylamine and 2-chloroethanol, and solubilization with sodium dodecyl sulfate (SDS) followed by preparative SDS-polyacrylamide gel electrophoresis. All three methods yield a single protein which precipitates with anti-rat plasma AAT antibody, and which has an apparent molecular weight of 45,000 daltons, in contrast to the molecular weight of plasma AAT, 50,000 daltons. Unlike plasma AAT, granule AAT contains no sialic acid, galactose, or fucose. Moreover, granule AAT contains a reduced amount of N-acetylglucosamine and an increased amount of mannose, compared with plasma AAT. The carbohydrate content of granule AAT varies with the isolation procedure used. Granule AAT is susceptible to cleavage by endoglucosaminidase H, which indicates the presence of high-mannose type oligosaccharides. Comparison of the molecular weight, carbohydrate composition, isoelectric point, and endoglucosaminidase H sensitivity of granule AAT isolated from rats with GalNH2-induced AAT deficiency with granule AAT from PiZ humans extends the list of similarities between experimental GalNH2-induced AAT deficiency in rats by and genetically determined AAT deficiency in humans.
在大鼠中持续给予半乳糖胺（GalNH2）可使血浆α1-抗胰蛋白酶（AAT）水平降至对照水平的10% - 50%，并诱导形成对淀粉酶有抗性、过碘酸希夫反应（PAS）阳性的颗粒，这些颗粒存在于肝细胞中且含有AAT。本报告描述了通过三种不同方法分离和纯化肝颗粒AAT：用盐酸胍溶解后在Bio - gel A5M上进行凝胶过滤、用甲胺和2 - 氯乙醇提取以及用十二烷基硫酸钠（SDS）溶解后进行制备性SDS - 聚丙烯酰胺凝胶电泳。所有这三种方法都产生一种单一蛋白质，它能与抗大鼠血浆AAT抗体沉淀，其表观分子量为45,000道尔顿，与血浆AAT的分子量50,000道尔顿不同。与血浆AAT不同，颗粒AAT不含唾液酸、半乳糖或岩藻糖。此外，与血浆AAT相比，颗粒AAT含有减少量的N - 乙酰葡糖胺和增加量的甘露糖。颗粒AAT的碳水化合物含量随所使用的分离程序而变化。颗粒AAT易被内切葡糖胺酶H切割，这表明存在高甘露糖型寡糖。将从GalNH2诱导的AAT缺乏大鼠中分离的颗粒AAT与PiZ型人类的颗粒AAT在分子量、碳水化合物组成、等电点和内切葡糖胺酶H敏感性方面进行比较，扩展了大鼠实验性GalNH2诱导的AAT缺乏与人类遗传性AAT缺乏之间的相似性列表。
