Potential of Plant Proteins Digested In Silico by Gastrointestinal Enzymes as Nutritional Supplement for COVID-19 Patients

Currently, no specific drug and vaccine are available for the new coronavirus SARS-CoV-2, and nutritional supplementation should be helpful. This study tried to provide reference for protein supplementation. Specifically, in silico method was employed to simulate protein degradation by gastrointestinal enzymes and to produce a large number of active peptides, then, the binding ability of these peptides to SARS-CoV-2 spike protein receptor-binding domain (RBD) was evaluated. The results showed that wheat-derived alpha/beta-gliadin, oat-derived avenin, and ribulose bisphosphate carboxylase small chain of different origin could be good protein source in generating potent binders to SARS-CoV-2 spike RBD. In addition, some high-affinity oligopeptides (such as PISCR, VQVVN, PQQQF, etc.) were identified as potential binders of SARS-CoV-2 spike RBD. In summary, a number of plant proteins could be helpful for COVID-19 patients when supplemented with these proteins, the identified oligopeptides could be used as lead compound to design potential entry inhibitors against SARS-CoV-2.