Takahashi N, Ortel T L, Putnam F W
Proc Natl Acad Sci U S A. 1984 Jan;81(2):390-4. doi: 10.1073/pnas.81.2.390.
We have determined the amino acid sequence of the amino-terminal 67,000-dalton (67-kDa) fragment of human ceruloplasmin and have established overlapping sequences between the 67-kDa and 50-kDa fragments and between the 50-kDa and 19-kDa fragments. The 67-kDa fragment contains 480 amino acid residues and three glucosamine oligosaccharides. These results together with our previous sequence data for the 50-kDa and 19-kDa fragments complete the amino acid sequence of human ceruloplasmin. The polypeptide chain has a total of 1,046 amino acid residues (Mr 120,085) and has attachment sites for four glucosamine oligosaccharides; together these account for the total molecular mass of human ceruloplasmin (132 kDa). The sequence analysis of the peptides overlapping the fragments showed that one additional amino acid, arginine, is present between the 67-kDa and 50-kDa fragments, and another, lysine, is between the 50-kDa and 19-kDa fragments. Only two apparent sites of amino acid interchange have been identified in the polypeptide chain. Both involve a single-point interchange of glycine and lysine that would result in a difference in charge. The results of the complete sequence analysis verified that human ceruloplasmin is composed of a single polypeptide chain and that the subunit-like fragments are produced by proteolytic cleavage during purification (and possibly also in vivo).
我们已经确定了人铜蓝蛋白氨基末端67000道尔顿（67 kDa）片段的氨基酸序列，并确定了67 kDa与50 kDa片段之间以及50 kDa与19 kDa片段之间的重叠序列。67 kDa片段包含480个氨基酸残基和三个氨基葡萄糖寡糖。这些结果连同我们先前获得的50 kDa和19 kDa片段的序列数据，完成了人铜蓝蛋白的氨基酸序列。该多肽链共有1046个氨基酸残基（Mr 120,085），并具有四个氨基葡萄糖寡糖的附着位点；这些共同构成了人铜蓝蛋白的总分子量（132 kDa）。对与各片段重叠的肽段进行序列分析表明，在67 kDa和50 kDa片段之间存在一个额外的氨基酸，即精氨酸，在50 kDa和19 kDa片段之间存在另一个氨基酸，即赖氨酸。在多肽链中仅鉴定出两个明显的氨基酸交换位点。两者均涉及甘氨酸和赖氨酸的单点交换，这将导致电荷差异。完整序列分析的结果证实，人铜蓝蛋白由一条多肽链组成，且这些亚基样片段是在纯化过程中（可能也在体内）通过蛋白水解裂解产生的。
