Characterization of the hemoglobin of the backswimmer Anisops deanei (Hemiptera).
Characterization of the hemoglobin of the backswimmer Anisops deanei (Hemiptera).
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DOI：
10.1016/j.ibmb.2012.04.007
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发表时间：
2012-09
影响因子：
3.8
通讯作者：
Agnes Wawrowski;P. G. D. Matthews;E. Gleixner;L. Kiger;M. Marden;T. Hankeln;T. Burmester
中科院分区：
文献类型：
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作者：
Agnes Wawrowski;P. G. D. Matthews;E. Gleixner;L. Kiger;M. Marden;T. Hankeln;T. Burmester
虽然O2结合血红蛋白样蛋白存在于许多昆虫中，但仅在少数物种中发现了显着的血红蛋白。Anisops属和Buenoa属（Notonectidae）的后泳者在腹部的大气管细胞中具有高浓度的血红蛋白。血红蛋白中的氧气被输送到气泡中，并控制浮力密度，这使得虫子能够在不游泳的情况下保持位置，并在它们捕食的中层水域保持静止。通过RT-PCR和RACE技术获得了三条异柳鱼血红蛋白链的cDNA序列。推导的氨基酸序列显示出一个不寻常的插入一个单一的氨基酸在保守的螺旋E，但这并不影响蛋白质的稳定性或配体结合动力学。重组Deanei血红蛋白具有P50= 2.4 kPa（18 kPa）的氧亲和力，并显示存在二聚体部分或两种不同构象。吸收光谱表明，该血红蛋白是一种典型的五配位珠蛋白。系统发育分析表明，回游血红蛋白Heteroptera内进化，最有可能起源于细胞内的血红蛋白具有不同的功能。
While O2-binding hemoglobin-like proteins are present in many insects, prominent amounts of hemoglobin have only been found in a few species. Backswimmers of the genera Anisops and Buenoa (Notonectidae) have high concentrations of hemoglobin in the large tracheal cells of the abdomen. Oxygen from the hemoglobin is delivered to a gas bubble and controls the buoyant density, which enables the bugs to maintain their position without swimming and to remain stationary in the mid-water zone where they hunt for prey. We have obtained the cDNA sequences of three Anisops deanei hemoglobin chains by RT-PCR and RACE techniques. The deduced amino acid sequences show an unusual insertion of a single amino acid in the conserved helix E, but this does not affect protein stability or ligand binding kinetics. Recombinant A. deanei hemoglobin has an oxygen affinity of P50= 2.4 kPa (18 torr) and reveals the presence of a dimeric fraction or two different conformations. The absorption spectra demonstrate that the Anisops hemoglobin is a typical pentacoordinate globin. Phylogenetic analyses show that the backswimmer hemoglobins evolved within Heteroptera and most likely originated from an intracellular hemoglobin with divergent function.