Cecropin P1 and novel nematode cecropins:: a bacteria-inducible antimicrobial peptide family in the nematode Ascaris suum
Cecropin P1 and novel nematode cecropins:: a bacteria-inducible antimicrobial peptide family in the nematode Ascaris suum
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DOI：
10.1042/bj20050218
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发表时间：
2005-08-15
影响因子：
4.1
通讯作者：
Kato, Y
中科院分区：
文献类型：
--
作者：
Pillai, A;Ueno, S;Kato, Y
抗菌肽Cecropin PI是从猪肠中分离得到的一种哺乳动物抗菌肽。已经报道了许多旨在表征这种肽的研究。最近，发现该肽的工作人员纠正了他们原来的结论，证实该肽实际上来源于猪肠道寄生线虫--蛔虫游动。在本研究中，我们进行了一个半穷举搜索细菌诱导的转录本在A。用cDNA差减法克隆了猪的cDNA。天蚕素P1和新的蛔虫天蚕素P2、P3和P4的转录产物被发现是正诱导因子。化学合成的蛔虫天蚕素对广泛的微生物具有杀菌作用，即革兰氏阳性（金黄色葡萄球菌、枯草芽孢杆菌和藤黄微球菌）和革兰氏阴性（铜绿假单胞菌、鼠伤寒沙门氏菌、粘质沙雷氏菌和大肠杆菌）细菌，并且对酵母菌（酿酒酵母和白色念珠菌）具有微弱但可检测的活性。天蚕素PI样序列也至少在蛔虫科的其他两个物种（蛔虫和犬弓蛔虫）中检测到。所有蛔虫天蚕素前体都含有一个酸性前区，在C-末端由一个四碱裂解位点连接。据报道，这种酸性前区也存在于被囊动物天蚕抗菌肽型抗菌肽styelin中。根据线虫和被囊动物的进化位置，祖先的天蚕素可能在C-末端含有酸性前区。
Cecropin PI was first identified as a mammalian antimicrobial peptide isolated from the pig intestine. Much research aimed at characterizing this peptide has been reported. Recently, the workers who discovered the peptide corrected their original conclusion, and confirmed that this peptide originates in fact from the pig intestinal parasitic nematode, Ascaris swim. In the present study, we carried out a semi-exhaustive search for bacteria-inducible transcripts in A. suum by the cDNA subtraction method. The transcripts encoding cecropin P1 and novel Ascaris cecropins, designated cecropins P2, P3 and P4, were found to be positively induced factors. Chemically synthesized Ascaris cecropins were bactericidal against a wide range of microbes, i.e. Gram-positive (Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus) and Gram-negative (Pseudomonas aeruginosa, Salmonella typhimurium, Serratia marcescens and Esherichia coli) bacteria, and were weakly but detectably active against yeasts (Saccharomyces cerevisiae and Candida albicans). Cecropin PI-like sequences were also detected at least in two other species (Ascaris lumbri-coides and Toxocara canis) of the Ascarididae. All Ascaris cecropin precursors contain an acidic pro-region connected by a tetrabasic cleavage site at the C-terminus. Such an acidic pro-region is also reported to be present in the tunicate cecropin-type antimicrobial peptide styelin. On the basis of the evolutionary position of nematodes and tunicates, the ancestral cecropin may have contained the acidic pro-region at the C-terminus.