Linzen B, Soeter N M, Riggs A F, Schneider H J, Schartau W, Moore M D, Yokota E, Behrens P Q, Nakashima H, Takagi T
Science. 1985 Aug 9;229(4713):519-24. doi: 10.1126/science.4023698.
Hemocyanins are large multi-subunit copper proteins that transport oxygen in many arthropods and molluscs. Comparison of the amino acid sequence data for seven different subunits of arthropod hemocyanins from crustaceans and chelicerates shows many highly conserved residues and extensive regions of near identity. This correspondence can be matched closely with the three domain structure established by x-ray crystallography for spiny lobster hemocyanin. The degree of identity is particularly striking in the second domain of the subunit that contains the six histidines which ligate the two oxygen-binding copper atoms. The polypeptide architecture of spiny lobster hemocyanin appears to be the same in all arthropods. This structure must therefore be at least as old as the estimated time of divergence of crustaceans and chelicerates, about 540 to 600 million years ago.
血蓝蛋白是在许多节肢动物和软体动物中运输氧气的大型多亚基铜蛋白。对来自甲壳类动物和螯肢动物的节肢动物血蓝蛋白七个不同亚基的氨基酸序列数据进行比较，发现许多高度保守的残基和近乎相同的广泛区域。这种对应关系可以与通过X射线晶体学确定的多刺龙虾血蓝蛋白的三结构域结构紧密匹配。在含有连接两个氧结合铜原子的六个组氨酸的亚基的第二个结构域中，相同程度尤为显著。多刺龙虾血蓝蛋白的多肽结构在所有节肢动物中似乎都是相同的。因此，这种结构至少与大约5.4亿至6亿年前甲壳类动物和螯肢动物估计的分化时间一样古老。
