Shishikura Fumio
Biology Department, Nihon University School of Medicine, 30-1 Oyaguchi-kami-machi, Itabash, Tokyo 173-8610, Japan.
Comp Biochem Physiol B Biochem Mol Biol. 2004 Apr;137(4):443-54. doi: 10.1016/j.cbpc.2004.01.003.
The amino acid sequences of four globins from the land leech, Haemadipsa zeylanica var. japonica, were determined using nucleotide sequencing and protein sequencing. The mature globin-molecules were composed of 146 amino acid residues for M-1 globin, 156 for M-2 globin, 143 for D-1 globin, and 149 for D-2 globin. Alignment of the four kinds of globins by Clustal X revealed 22 invariant amino acids. The four globins were 26-33% identical. A striking feature of amino acid alteration was: the replacement of the E7 distal-His of D-1 globin by phenylalanine because histidine is conserved among the rest of the globins of H. zeylanica, those of other representative species (Lumbricus and Tylorrhynchus) of Annelida and most other hemoglobins. A phylogenetic tree constructed of 18 globin structures including two species of leeches, H. zeylanica (a land leech) and Macrobdella decora (a freshwater leech), T. heterochaetus (a representative species of polychaetes), L. terrestris (a representative species of oligochaetes), and human alpha and beta globins strongly indicated that the leech globins first separated from globin lineage of annelids.
利用核苷酸测序和蛋白质测序技术，测定了日本山蛭（Haemadipsa zeylanica var. japonica）四种珠蛋白的氨基酸序列。成熟的珠蛋白分子中，M-1珠蛋白由146个氨基酸残基组成，M-2珠蛋白由156个组成，D-1珠蛋白由143个组成，D-2珠蛋白由149个组成。通过Clustal X对这四种珠蛋白进行比对，发现有22个不变氨基酸。这四种珠蛋白的同源性为26%-33%。氨基酸变化的一个显著特征是：D-1珠蛋白的E7位远端组氨酸被苯丙氨酸取代，因为在日本山蛭的其他珠蛋白、环节动物门其他代表性物种（蚯蚓和白线蚓）的珠蛋白以及大多数其他血红蛋白中，组氨酸都是保守的。由18种珠蛋白结构构建的系统发育树，包括两种水蛭（日本山蛭（一种陆生水蛭）和美洲医蛭（一种淡水水蛭））、杂色真蚓（多毛纲的一个代表性物种）、陆正蚓（寡毛纲的一个代表性物种）以及人类α和β珠蛋白，有力地表明水蛭珠蛋白首先从环节动物的珠蛋白谱系中分离出来。
