Antimicrobial activity of a bovine hemoglobin fragment in the tick Boophilus microplus
Antimicrobial activity of a bovine hemoglobin fragment in the tick Boophilus microplus
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DOI：
10.1074/jbc.274.36.25330
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发表时间：
1999-09-03
影响因子：
4.8
通讯作者：
Daffre, S
中科院分区：
文献类型：
--
作者：
Fogaça, AC;da Silva, PI;Daffre, S
在牛体微小牛蜱的血淋巴和肠道内容物中检测到抗真菌和抗菌活性。用反相层析法从扁虱肠道内容物中提纯了一种具有抗菌活性的多肽。用基质辅助激光解吸电离质谱仪测定纯化多肽的相对分子质量为3,205.7 Da。通过Edman降解得到的氨基酸序列表明，该多肽与牛铜血红蛋白的一段相同。根据获得的序列合成的多肽显示与分离材料相同的表征数据，证实了其结构。合成的多肽对革兰氏阳性细菌和真菌具有微摩尔浓度的活性。这些数据使我们得出结论，在扁虱肠道内容物中检测到的抗菌活性是宿主蛋白质--血红蛋白--酶处理的结果。这种活动可能被扁虱用来防御微生物。
Antifungal and antibacterial activities were detected in the hemolymph and gut contents of the cattle tick, Boophilus microplus. A peptide with antibacterial activity from the tick gut contents was purified to homogeneity by reversed-phase chromatography. The molecular mass of the purified peptide was 3,205.7 Da, measured by matrix-assisted laser desorption/ionization mass spectrometry. The amino acid sequence was obtained by Edman degradation and showed that the peptide was identical to a fragment of the bovine cu-hemoglobin. A synthetic peptide based on the sequence obtained showed characterization data identical to those of the isolated material, confirming its structure. The synthetic peptide was active in micromolar concentrations against Gram-positive bacteria and fungi. These data led us to conclude that the antibacterial activity detected in tick gut contents is the result of enzymatic processing of a host protein, hemoglobin. This activity may be used by ticks as a defense against microorganisms.