title: The New Antimicrobial Peptide SpHyastatin from the Mud Crab Scylla paramamosain with Multiple Antimicrobial Mechanisms and High Effect on Bacterial Infection.
abstract: SpHyastatin was first identified as a new cationic antimicrobial peptide in hemocytes of the mud crab Scylla paramamosain. Based on the amino acid sequences deduced, it was predicted that this peptide was composed of two different functional domains, a proline-rich domain (PRD) and a cysteine-rich domain (CRD). The recombinant product of SpHyastatin displayed potent antimicrobial activities against the human pathogen Staphylococcus aureus and the aquatic animal pathogens Aeromonas hydrophila and Pseudomonas fluorescens. Compared with the CRD of SpHyastatin, the PRD presented better antimicrobial and chitin binding activities, but both regions were essential for allowing SpHyastatin complete antimicrobial activity. The binding properties of SpHyastatin to different microbial surface molecules suggested that this might be an initial and crucial step for performing its antimicrobial activities. Evaluated using propidium iodide uptake assays and scanning electron microscopy images, the antimicrobial mechanism of SpHyastatin was found to be prone to disrupt cell membrane integrity. Interestingly, SpHyastatin exerted its role specifically on the surface of S. aureus and Pichia pastoris whereas it directly killed P. fluorescens through simultaneous targeting the membrane and the cytoplasm, indicating that SpHyastatin could use different antimicrobial mechanisms to kill different species of microbes. As expected, the recombinant SpHyastatin increased the survival rate of crabs challenged with Vibrio parahaemolyticus. In addition, SpHyastatin could modulate some V. parahaemolyticus-responsive genes in S. paramamosain.
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Zhongguo
authors: Z
authors: Shan
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Kexin
authors: K
authors: Zhu
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen UniversityXiamen, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen UniversityXiamen, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, Xiamen UniversityXiamen, China.
authors: Hui
authors: H
authors: Peng
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Bei
authors: B
authors: Chen
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Jie
authors: J
authors: Liu
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen UniversityXiamen, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen UniversityXiamen, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, Xiamen UniversityXiamen, China.
authors: Fangyi
authors: F
authors: Chen
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Xiaowan
authors: X
authors: Ma
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Shuping
authors: S
authors: Wang
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen University Xiamen, China.
authors: Kun
authors: K
authors: Qiao
authors: State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Science, Xiamen UniversityXiamen, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen UniversityXiamen, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, Xiamen UniversityXiamen, China.
authors: Kejian
authors: K
authors: Wang
keywords: Scylla paramamosain; SpHyastatin; antimicrobial mechanism; antimicrobial peptide; immune protection; membrane permeabilization