Kingston I B, Kingston B L, Putnam F W
Proc Natl Acad Sci U S A. 1979 Apr;76(4):1668-72. doi: 10.1073/pnas.76.4.1668.
The complete amino acid sequence has been determined for a fragment of human ceruloplasmin [ferroxidase; iron(II):oxygen oxidoreductase, EC 1.16.3.1]. The fragment (designated Cp F5) contains 159 amino acid residues and has a molecular weight of 18,650; it lacks carbohydrate, is rich in histidine, and contains one free cysteine that may be part of a copper-binding site. This fragment is present in most commercial preparations of ceruloplasmin, probably owing to proteolytic degradation, but can also be obtained by limited cleavage of single-chain ceruloplasmin with plasmin. Cp F5 probably is an intact domain attached to the COOH-terminal end of single-chain ceruloplasmin via a labile interdomain peptide bond. A model of the secondary structure predicted by empirical methods suggests that almost one-third of the amino acid residues are distributed in alpha helices, about a third in beta-sheet structure, and the remainder in beta turns and unidentified structures. Computer analysis of the amino acid sequence has not demonstrated a statistically significant relationship between this ceruloplasmin fragment and any other protein, but there is some evidence for an internal duplication.
已确定人铜蓝蛋白[亚铁氧化酶;铁(II):氧氧化还原酶,EC 1.16.3.1]一个片段的完整氨基酸序列。该片段(命名为Cp F5)含有159个氨基酸残基,分子量为18,650;它不含碳水化合物,富含组氨酸,并且含有一个游离半胱氨酸,可能是铜结合位点的一部分。这个片段存在于大多数铜蓝蛋白的商业制剂中,可能是由于蛋白水解降解,但也可以通过用纤溶酶对单链铜蓝蛋白进行有限切割获得。Cp F5可能是一个完整的结构域,通过一个不稳定的结构域间肽键连接到单链铜蓝蛋白的COOH末端。通过经验方法预测的二级结构模型表明,几乎三分之一的氨基酸残基分布在α螺旋中,约三分之一在β折叠结构中,其余的在β转角和未确定的结构中。对氨基酸序列的计算机分析尚未证明该铜蓝蛋白片段与任何其他蛋白质之间存在统计学上显著的关系,但有一些证据表明存在内部重复。