Das Hemen, Ahmed Shahaj Uddin, More Tukaram
Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India.
DNA Seq. 2008 Jun;19(3):347-56. doi: 10.1080/10425170701606219.
Cathelicidins represent a diverse family of endogenous cationic antibiotic peptide present in all mammalian species. In the present study, a novel cathelicidin cDNA was identified and characterized from bone marrow cells of buffalo (Bubalus bubalis) using RT-PCR based approach. The cDNA encodes a propeptide of 1.18 kDa with net positive charge at neutral pH. The precursor peptide possesses a signal peptide of 29 amino acids and a biologically active peptide of 34 residues. Comparison of sequences indicates only 66.1 and 64.1% identity at nucleotides and amino acids level respectively, with the already reported cathelicidin congener from the same species. However, high degree of similarity (92.8% nucleotides and 81.9% amino acids) was noticed with cathelicidin 7 sequence of Bos taurus suggesting interspecies conservation of cathelicidin peptides rather than intra-species within bovidae family. Phylogenetic trees analyses also support these data. Our findings, further justify the cloned cDNA as a unique cathelicidin member of B. bubalis, and may reasonably considered to be another example of structural diversity exhibited by cathelicidin-derived peptides as reported from other mammals.
杀菌肽是所有哺乳动物物种中存在的多种内源性阳离子抗菌肽家族。在本研究中,使用基于RT-PCR的方法从水牛(Bubalus bubalis)的骨髓细胞中鉴定并表征了一种新型杀菌肽cDNA。该cDNA编码一个1.18 kDa的前肽,在中性pH下带净正电荷。前体肽具有一个29个氨基酸的信号肽和一个34个残基的生物活性肽。序列比较表明,与同一物种中已报道的杀菌肽同源物相比,核苷酸和氨基酸水平的同一性分别仅为66.1%和64.1%。然而,与牛(Bos taurus)的杀菌肽7序列具有高度相似性(92.8%的核苷酸和81.9%的氨基酸),这表明杀菌肽在不同物种间具有保守性,而非在牛科动物的种内保守。系统发育树分析也支持这些数据。我们的研究结果进一步证明克隆的cDNA是水牛独特的杀菌肽成员,并且可以合理地认为是其他哺乳动物报道的杀菌肽衍生肽所表现出的结构多样性的另一个例子。