Proteomic Analysis of Vibrio parahaemolyticus-Stimulated Pinctada martensii Proteins for Antimicrobial Activity, Potential Mechanisms, and Key Components

<b>Background:</b> Bacterial infections are a major challenge in food processing and public health, and there is an urgent need to develop novel antimicrobial agents. <b>Objectives:</b> The purpose of this study is to investigate the potential mechanism and key components of <i>Pinctada martensii</i> antimicrobial proteins (Pm-Aps) to provide a theoretical basis for the development of novel antimicrobial agents. <b>Methods:</b> The researchers used <i>Vibrio parahaemolyticus</i> (VP) to stimulate <i>Pinctada martensii</i>, extracted the antimicrobial proteins, and analyzed their antimicrobial activities, potential mechanisms of action, and key components using proteomics. <b>Results:</b> The results showed that the antimicrobial activity of Pm-Aps, with broad-spectrum antimicrobial effects, was significantly enhanced after VP stimulation. This was associated with the upregulation of <i>LAAO</i>, <i>CHDH</i>, <i>TLR2</i>, <i>ATG16L1</i>, <i>BAK</i>, <i>CLCA4</i>, and <i>CASP8</i> and the downregulation of <i>MCM3</i>, <i>MCM5</i>, <i>DTYMK</i>, <i>PLK1</i>, <i>FBXO6</i>, <i>LPCAT3</i>, <i>GST</i>, <i>LAMTOR5</i>, <i>CYP17A</i>, <i>CTSA</i>, and <i>RRM1</i>. It is hypothesized that these proteins may inhibit bacterial growth and multiplication by activating immune-related signaling pathways, inhibiting DNA replication and repair, and inducing apoptosis and autophagy. Furthermore, it was found that <i>LAAO</i> may be a key component of the antimicrobial action of Pm-Aps, killing bacteria by catalyzing the oxidation of amino acids to produce hydrogen peroxide (H₂O₂). <b>Conclusions:</b> These results strongly suggest that Pm-Aps is an effective antimicrobial protein, and it is expected that new <i>LAAO</i> can be obtained from Pm-Aps.