Abstract:While the COVID-19 pandemic and COVID-19-related mortality in China have been under control, SARSCoV-2 remains infectious and transmissible. Inhibiting the activity of SARS-CoV-2 main protease (SARS-CoV-2 Mpro) can reduce viral infectivity. A screen for peptides from Porphyra haitanensis proteins with inhibitory potency toward SARSCoV-2 Mpro was performed, and twenty-nine P. haitanensis proteins identified through a literature search. Ten representative proteins were selected from among them based on predicted physicochemical properties and potential allergenicity. These representative proteins were subsequently subjected to simulated gastrointestinal hydrolysis to screen out the peptides with lengths in the range of 2~5 amino acids. These were subjected to predictive screening based on the physicochemical properties of the peptides of Porphyra haitanensis. Twenty-one hydrophilic and non-toxic peptides with no potential allergenicity were identified and assessed as ligands for the receptor SARS-CoV-2 Mpro. Bioactive peptides with high affinity for the target protein were identified by molecular docking, and the binding modes and interactions between the bioactive peptides and the target protein were analyzed by 2D and 3D visualization. Some of the active peptides entered the active center of the target protein and bound to SARS-CoV-2 Mpro forming hydrogen bonds, π-bonds, and alkyl bonds. The peptide that exhibited the highest bound fraction was DDGSF (145.441), followed by DQF (143.819), and then DGPW (141.446). These studies suggest that peptides have the potential to inhibit SARS-CoV-2 Mpro, and that P. haitanensis proteins thus have potential as nutritional supplements with possible protective efficacy against SARS-CoV-2.
