Directorate of Coldwater Fisheries Research, Bhimtal, Nainital, 263136, Uttarakhand, India.
Protein J. 2014 Feb;33(1):1-10. doi: 10.1007/s10930-013-9530-1.
Innate immune system is a primary line of defense in fish that protects it from the invading pathogens. Antimicrobial peptides (AMPs) are widely distributed in nature and are essential components of innate immunity. These molecules enable the host's innate immune system to fight against a variety of infectious agents. One such AMP, hepcidin, is a cysteine rich amphipathic peptide. We have amplified, cloned and characterized hepcidin like AMP from Schizothorax richardsonii that inhabits one of the most difficult aquatic ecosystems in the Indian Himalayas. The cDNA encoding hepcidin like peptide was amplified as a 371 bp fragment with an open reading frame (ORF) of 279 nucleotides flanked by 5' and 3' UTRs of 70 and 22 bases respectively. This ORF encodes a peptide of 93 amino acids with a signal peptide of 24 amino acids and a mature peptide of 25 amino acids. The mature hepcidin like peptide of S. richardsonii has eight cystine residues that participate in the formation of four disulfide bonds, a unique feature of hepcidin like AMPs. A 3D model of hepcidin like mature peptide was generated using Modeller 9.10 which was validated using PROCHECK and ERRAT. Phylogenetic analysis of hepcidin like AMP from S. richardsonii revealed that it was closely related to hepcidin from olive barb (Puntius sarana).
先天免疫系统是鱼类的第一道防线，可保护其免受入侵病原体的侵害。抗菌肽（AMPs）广泛存在于自然界中，是先天免疫系统的重要组成部分。这些分子使宿主的先天免疫系统能够抵御各种感染因子。其中一种 AMP 是富含半胱氨酸的两亲肽——hepcidin。我们从栖息于印度喜马拉雅山脉最恶劣水生生态系统之一的齐口裂腹鱼（Schizothorax richardsonii）中扩增、克隆并鉴定了类似 hepcidin 的 AMP。编码类似 hepcidin 的肽的 cDNA 被扩增为 371bp 片段，其开放阅读框（ORF）为 279 个核苷酸，侧翼为 5'和 3'UTR 分别为 70 和 22 个碱基。该 ORF 编码一个由 93 个氨基酸组成的肽，其中包括 24 个氨基酸的信号肽和 25 个氨基酸的成熟肽。齐口裂腹鱼的类似 hepcidin 的成熟肽有 8 个半胱氨酸残基参与形成四个二硫键，这是 hepcidin 样 AMP 的一个独特特征。使用 Modeller 9.10 生成了类似 hepcidin 的成熟肽的 3D 模型，并使用 PROCHECK 和 ERRAT 进行了验证。齐口裂腹鱼类似 hepcidin 的 AMP 的系统发育分析表明，它与橄榄巴鱼（Puntius sarana）的 hepcidin 密切相关。
