Antimicrobial peptides, which are crucial effectors of innate immunity, are a promising substitute for antibiotics. The piscidin family is a group of fish-derived antimicrobial peptides that have potent antimicrobial activity and participate in the innate immune response. Here we describe a novel piscidin-like peptide called cerocin from the black sea bass (Centropristis striata), which is a highly valued marine teleost in both commercial and recreational fisheries worldwide. The full-length cDNA of cerocin consists of 567 base pairs, including 5′ and 3′ untranslated regions of 61 and 209 base pairs, respectively. The active peptide consists of 20 amino acids that form an amphipathic α-helix structure. Cerocin showed highest identity with the cardinalfish (Ostorhinchus fasciatus) piscidin (52%). Phylogenetic tree demonstrated that the cerocin clustered with dicentracin of Liparis tanakae and Perca flavescens. It showed tissue-specific distribution patterns and was predominantly expressed in the gill. After challenge with Vibrio harveyi, C. striata showed time- and tissue-dependent expression of the cerocin gene. Finally, a cerocin peptide was synthesized, and it exerted broad-spectrum antimicrobial activity against a number of bacterial strains, especially Gram-positive pathogens. Analysis of the killing kinetics revealed that the cerocin peptide had a rapid bactericidal effect on the bacteria. Collectively, these data suggest that the piscidin-like cerocin might play a vital role in the immune response of C. striata, and further studies of this gene may provide insight into the innate immune system of this species.

抗菌肽是先天免疫的关键效应物，是抗生素的有前途的替代品。piscidin家族是一组鱼类衍生的抗菌肽，具有强大的抗菌活性并参与先天免疫反应。在这里，我们描述了一种来自黑鲈（Centropristis striata）的名为cerocin的新型piscidin样肽，它是全球商业和休闲渔业中极受重视的海洋硬骨鱼。cerocin的全长cDNA由567个碱基对组成，分别包括61和209个碱基对的5'和3'非翻译区。活性肽由20个氨基酸组成，形成两亲性α-螺旋结构。Cerocin与红衣鱼的身份最高（Ostorhinchus fasciatus piscidin（52％）。系统发育树表明，cererocin与Liparis tanakae和Perca flavescens的dicentracin聚集在一起。它显示了组织特异性的分布模式，并主要在g中表达。用哈维氏弧菌攻击后，纹状体梭状芽胞杆菌显示出时间依赖性和组织依赖性的黄霉素表达基因。最后，合成了一种cerocin肽，它对多种细菌菌株，特别是革兰氏阳性病原体具有广谱抗菌活性。杀灭动力学的分析表明，塞罗霉素肽对细菌具有快速的杀菌作用。总的来说，这些数据表明，类似piscidin的cerocin可能在C. striata的免疫应答中起着至关重要的作用，对该基因的进一步研究可能提供对该物种固有免疫系统的洞察力。