CRYSTAL-STRUCTURE OF CLEAVED HUMAN ALPHA-1-ANTICHYMOTRYPSIN AT 2.7-A RESOLUTION AND ITS COMPARISON WITH OTHER SERPINS
CRYSTAL-STRUCTURE OF CLEAVED HUMAN ALPHA-1-ANTICHYMOTRYPSIN AT 2.7-A RESOLUTION AND ITS COMPARISON WITH OTHER SERPINS
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DOI：
10.1016/0022-2836(91)90704-a
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发表时间：
1991-04-05
影响因子：
5.6
通讯作者：
LAURELL, CB
中科院分区：
文献类型：
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作者：
BAUMANN, U;HUBER, R;LAURELL, CB
用Paterson搜索技术对丝氨酸蛋白酶抑制剂超家族成员α1-抗胰凝乳蛋白酶（ACT）的晶体结构进行了解析，在2.7 °分辨率下，R因子为18.0%，与标准键长和键角的平均偏差分别为0.013 °和3.1 °。最终模型由374个氨基酸残基、126个溶剂分子和5个糖残基组成。Asn 70可以明确地被鉴定为糖基化位点，Asn 104可能也被糖基化，切割的ACT的结构与切割的α1-抗胰蛋白酶（α 1-PI）和plakalphin进行了比较，这两种酶抑制剂分别是切割的和完整的丝氨酸蛋白酶抑制剂的原型模型。切割的ACT与切割的α 1 PI非常相似：特别是，它具有通过蛋白水解释放的s4 A链，作为中间链插入β折叠A中。ACT和α 1 PI仅在插入位点局部不同，除了s3 C-turn-s4 C片段，它被几个Δ ngström单位取代。ACT的这个区域参与DNA结合。
The crystal structure of proteolytically modified humanα1-antichymotrypsin (ACT), a member of the serpin superfamily, has been solved by Paterson search techniques and refined to anR-factor of 18.0% at 2.7 Å resolution with mean deviations from standard bond lengths and angles of 0.013 Å and 3.1 °, respectively. The final model consists of 374 amino acid residues, 126 solvent molecules and five sugar residues. Asn70 could be identified unambiguously as a glycosylation site and Asn104 is probably also glycosylated.The structure of cleaved ACT is compared with cleavedα1-antitrypsin (α1PI) and with plakalbumin, which are prototypical models for cleaved and intact serpins, respectively. Cleaved ACT is very similar to cleavedα1PI: in particular, it has strand s4A, which is liberated by proteolysis, inserted as the middle strand in β-sheet A. ACT andα1PI differ locally only at sites of insertions, except at the segment s3C-turn-s4C, which is displaced by several ångström units. This region of ACT is involved in DNA binding.