Properties of isolated human alpha1-antitrypsins of Pi types M, S and Z.
Properties of isolated human alpha1-antitrypsins of Pi types M, S and Z.
复制标题
Pi 型 M、S 和 Z 的分离人 α1-抗胰蛋白酶的特性。
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
M. Fagerhol
中科院分区：
文献类型：
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作者：
J. Jeppsson;C. Laurell;M. Fagerhol
1. α1-抗胰蛋白酶含有单个硫醇基团，该硫醇基团在天然血浆中被部分封闭，并且在轻度还原后具有反应性。 2. 利用反应性硫醇基团，通过硫醇二硫化物 (SH-SS) 交换反应，分离出具有天然微异质性的 Pi 型 F、M、S 和 Z 的人 α1-抗胰蛋白酶。 3. 给出了蛋白质 M 的各种微异质级分的 pI。α1-抗胰蛋白酶的逐步去唾液酸化表明主要级分之间的电荷差异是每个级分之间的一个唾液酸残基。用带正电或带负电的化合物取代单个硫醇时所获得的 pI 变化进一步证明了这一点。 4. 对每种 Pi 类型的纯化蛋白质进行去唾液酸化，将各个微异质级分转化为一个主要级分。研究变体的等电点变化表明蛋白质 M 和变体之间存在正负一或两个电荷单位的差异。 5.通过硫代巴比妥酸测定，蛋白质M和Z存在一个唾液酸残基的差异，但是用神经氨酸酶逐步去除唾液酸显示两种蛋白质的模式几乎相同的逐步变化，表明唾液酸残基的数量相同。 6. 电聚焦已被用来鉴定蛋白质 M、S 和 Z 中的 CNBr 片段。 7. 八个 CNBr 片段之一被发现存在氨基酸取代，蛋白质 M 中的谷氨酸被蛋白质 Z 中的赖氨酸取代。 8. 发现健康男性血浆中 α1-抗酪蛋白的平均浓度为 1.32 g/1。
1. alpha1-Antitrypsin contains a single thiol group partly blocked in native plasma and reactive after mild reduction. 2. Human alpha1-antitrypsins of Pi types F, M, S and Z have been isolated with native microheterogeneity using thiol-disulfide (SH-SS) interchange reactions utilizing the reactive thiol group. 3. The pI of the various microheterogeneous fractions are given for protein M. Stepwise desialylation of alpha1-antitrypsin indicates that the charge difference between the major fractions is one sialic acid residue between each. This is further supported by the pI changes obtained on substitution of the single thiol with positively or negatively charged compounds. 4. Desialyation of purified proteins from each Pi type converts the individual microheterogeneous fractions to one major fraction. The pI shift for the variants studied indicate a difference of plus or minus one or two charge units between protein M and the variants. 5. A difference of one sialic acid residue was obtained for proteins M and Z by the thiobarbituric assay, but stepwise removal of sialic acid with neuraminidase revealed almost identical stepwise change of pattern of both proteins indicating the same number of sialic acid residues. 6. Electrofocusing has been used to identify CNBr fragments from proteins M, S and Z. 7. An amino acid substitution has been found to be located in one of the eight CNBr fragments, glutamic acid in protein M is substituted by lysine in protein Z. 8. The average concentration of alpha1-antityprsin in plasma from healthy males was found to be 1.32 g/1.