Peritrophic membrane (PM) refers to a vital physical barrier enabling shrimp to resist pathogen invasion. It primarily consists of chitin and proteins, mostly chitin-binding protein (CBP). CBPs have been identified from microorganisms to higher organisms. In the present study, a CBP, designated MjCBP, was reported from Marsupenaeus japonicus. The open reading frame of MjCBP was 1854 bp, encoding a protein with 618 amino acids (MH544098). To be specific, the theoretical pI and molecular mass of mature MjCBP reached 5.43 and 66064.00 Da, respectively. MjCBP consisted of seven type Ⅱ chitin-binding domains (ChtB D2), which was up-regulated after being challenged with Vibrio anguillarum and then agglutinating several bacteria. In addition, MjCBP and the first chitin-binding domain (CBD1) could bind to several Gram-positive and Gram-negative bacteria via the binding process to lipopolysaccharides and peptidoglycans, whereas CBD1 was not capable of agglutinating bacteria. Moreover, the anterior and posterior segments of CBD1 were synthesized in vitro, and the posterior segment could bind to lipopolysaccharides. However, both segments fail to agglutinate bacteria. Furthermore, MjCBP and CBD1 facilitated the clearance of V. anguillarum in vivo, and the silencing of MjCBP via RNA interference reduced the ability of bacterial clearance. As revealed from the mentioned results, MjCBP acts as an opsonin or pattern recognition receptor to achieve antibacterial immune response in shrimp.

围营养膜 (PM) 是指使虾能够抵抗病原体入侵的重要物理屏障。它主要由几丁质和蛋白质组成，主要是几丁质结合蛋白（CBP）。已从微生物到高等生物中鉴定出 CBP。在本研究中，一种 CBP，命名为Mj CBP，是从Marsupenaeus japonicus中报道的。MjCBP的开放阅读框为1854 bp，编码618个氨基酸的蛋白质（MH544098）。具体而言，成熟MjCBP的理论pI和分子量分别达到5.43和66064.00 Da。MjCBP由7个Ⅱ型几丁质结合域（ChtB D2）组成，受到鳗弧菌攻击后上调然后凝集几种细菌。此外，MjCBP 和第一个几丁质结合域 (CBD1) 可以通过与脂多糖和肽聚糖的结合过程与几种革兰氏阳性和革兰氏阴性细菌结合，而 CBD1 不能凝集细菌。此外，CBD1的前段和后段是在体外合成的，后段可以与脂多糖结合。然而，这两个部分都不能凝集细菌。此外，MjCBP 和 CBD1 促进了体内V. anguillarum的清除，以及MjCBP的沉默通过 RNA 干扰降低了细菌清除能力。正如上述结果所揭示的，MjCBP 作为调理素或模式识别受体在虾中实现抗菌免疫反应。