Shishikura F, Snow J W, Gotoh T, Vinogradov S N, Walz D A
J Biol Chem. 1987 Mar 5;262(7):3123-31.
The giant extracellular hemoglobin (3,800 kDa) of the oligochaete Lumbricus terrestris consists of four subunits: a monomer (chain I), two subunits each of about 35 kDa (chains V and VI), and a disulfide-bonded trimer (50 kDa) of chains II, III, and IV. The complete amino acid sequence of chain I was determined: it consists of 142 amino acid residues and has a molecular weight of 16,750 including a heme group. Fifty-nine residues (42%) were found to be identical with those in the corresponding positions in Lumbricus chain II (Garlick, R. L., and Riggs, A. F. (1982) J. Biol. Chem. 257, 9005-9015); 45 (32%), 56 (40%), 44 (31%), and 45 (32%) residues were found to be in identical positions in the sequences of chains I, IIA, IIB, and IIC, respectively, of Tylorrhynchus heterochaetus hemoglobin (Suzuki, T., and Gotoh, T. (1986) J. Biol. Chem. 261, 9257-9267). When the sequences of all six annelid chains are compared, 18 invariant residues are found in the first 104 residues of the molecule; very little homology exists among the annelid chains in the carboxyl-terminal 38-residue region. Nine of the 18 invariant residues are also found in the human beta-globin chain.
寡毛纲动物蚯蚓的巨大细胞外血红蛋白（3800 kDa）由四个亚基组成：一个单体（链I）、两个各约35 kDa的亚基（链V和链VI）以及由链II、链III和链IV组成的二硫键连接的三聚体（50 kDa）。确定了链I的完整氨基酸序列：它由142个氨基酸残基组成，包括一个血红素基团在内的分子量为16750。发现59个残基（42%）与蚯蚓链II相应位置的残基相同（加利克，R. L.，和里格斯，A. F.（1982年）《生物化学杂志》257，9005 - 9015）；分别发现45个（32%）、56个（40%）、44个（31%）和45个（32%）残基在异唇蚓血红蛋白的链I、IIA、IIB和IIC序列中的相同位置（铃木，T.，和后藤，T.（1986年）《生物化学杂志》261，9257 - 9267）。当比较所有六条环节动物链的序列时，在分子的前104个残基中发现了18个不变残基；在羧基末端38个残基区域，环节动物链之间几乎没有同源性。在18个不变残基中有9个也存在于人类β - 珠蛋白链中。
