原虫外膜

Results Same conservative sites and key catalytic sites existed among SjLDH and LDHs from other species. Similarity of SjLDH compared to CsLDH, TvLDH and HsLDH was 75%, 17%, 58%-60% respectively. Phylogenetic analysis demonstrated that the evolution relation between SjLDH and DmLDH was closer than the relation between SjLDH and CeLDH, the relationship between SjLDH and HsLDH-B,-C was closer than HsLDH-A. Three trans-membrane regions were found, the region of 98aa-106aa in three hydrophilia regions located outside of membrane was inferred as the major antigen epitope. This antigen epitope had significant difference with LDHs from protozoon （ Pf ., Tg ., Tv .） and had 1-3 amino acid residue difference with MmLDH, HsLDH-A,-B,-C, and was the same with CsLDH. One of the key catalytic residues and substrate binding loop were located in this region. Tertiary structure demonstrated that 98aa-106aa was on the surface of the protein and formed a substrate binding loop, other two key catalytic sites were at the position near the loop.

结果 SjLDH与其他物种的同源序列含相同的保守位点及催化活性位点，与华支睾吸虫LDH同源性最高为75％，与阴道毛滴虫LDH同源性最低为17%，与人LDH（HsLDH-A，-B，-C）的同源性为58%~60％； SjLDH与果蝇的进化距离较秀丽隐杆线虫为近，3种人LDH中与HsLDH-B、-C的进化距离较HsLDH-A为近；该蛋白具有3个跨膜区域，3个高亲水性区域，主要的线性表位98aa~106aa位于膜外，与原虫LDH相同区域差异显著，而与其他LDH有1~3个氨基酸的差异，关键催化位点之一及底物丙酮酸结合区域位于该区域，蛋白质同源模建分析表明该区域位于蛋白表面形成环状结构，3个关键催化位点位于该区域或在其附近。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。