Targeting Inhibition of SmpB by Peptide Aptamer Attenuates the Virulence to Protect Zebrafish against Aeromonas veronii Infection

Abstract

Aeromonas veronii is an important pathogen of aquatic animals, wherein Small protein B (SmpB) is required for pathogenesis by functioning as both a component in stalled-ribosome rescue and a transcription factor in upregulation of virulence gene bvgS expression. Here a specific peptide aptamer PA-1 was selected from peptide aptamer library by bacterial two-hybrid system employing pBT-SmpB as bait. The binding affinity between SmpB and PA-1 was evaluated using enzyme-linked immunosorbent assay. The key amino acids of SmpB that interact with PA-1 were identified. After PA-1 was introduced into A. veronii, the engineered strain designated as A. veronii (pN-PA-1) was more sensitive and grew slower under salt stress in comparison with wild type, as the disruption of SmpB by PA-1 resulted in significant transcription reductions of virulence-related genes. Consistent with these observations, A. veronii (pN-PA-1) was severely attenuated in model organism zebrafish, and vaccination of zebrafish with A. veronii (pN-PA-1) induced a strong antibody response. The vaccinated zebrafish were well protected against subsequent lethal challenges with virulent parental strain. Collectively, we propose that targeting inhibition of SmpB by peptide aptamer PA-1 possesses the desired qualities for a live attenuated vaccine against pathogenic A. veronii.

First-in-class matrix anti-assembly peptide prevents staphylococcal biofilmin vitroandin vivo

“…Briefly, we monitored the real-time molecular self-assembly reaction by measuring the optical density at 600 nm (OD 600 ) as a function of time with or without capsicumicine. As a negative control, we used PA-1, a similarly sized peptide ( 40, 41 ). OD increases when capsicumicine is present, which shows that the molecular self-assembly process is quicker overall (Fig.…”

Capsicumicine, a New Bioinspired Peptide from Red Peppers Prevents Staphylococcal Biofilm In Vitro and In Vivo via a Matrix Anti-Assembly Mechanism of Action

“…Acetic acid and NaOH were used to adjust pH, and the reaction temperature was about 30°C. As a negative control, a similarly sized peptide was used, PA-1 ( 62 ).…”

Screening and application of peptamers

“…肽适体筛可以通过多种方式进行(表2), 其中有较 为传统的酵母双杂交技术, 噬菌体展示技术 [24] , 核糖 体展示技术 [25] , mRNA展示技术 [26] 等以及新兴的基于 生物信息学的分子对接模拟方法 [27] . (prey)之间是否存在相互作用(图1) [28] . 酵母双杂交技 术只能筛选以蛋白或多肽为靶标的肽适体, 且不太适 用于分子量较小的靶标.…”

“…通过肽适体限制初级神经元上的TRPV1 也是非常有效的止痛手段 [72] . 依据肽适体调控转录因 子活性的思路, 肽适体可对气单胞菌的生命活动起到 抑制作用, 进而具有水产抗生素替代前景 [87] , 接种肽 适体疫苗后的斑马鱼在致病条件下也得到了存活 [28] . ; 不同的肿瘤可能具有一致的癌症靶标例如分化 或DNA结合蛋白抑制剂(ID)在卵巢癌和乳腺癌中均不 正常表达 [76,77] , 因此也可筛选出较广泛的抗肿瘤药物; 研究表明, 肽适体可以通过使肿瘤细胞增强对抗肿瘤 药物的敏感性, 从而在与抗肿瘤药物的协同作用下提 高癌细胞辐射敏感度, 这使得肽适体和射线联合疗法 成为肿瘤治疗手段 [75] .…”