Using computer simulation, Indian scientists have found that a natural food-preservative molecule has the potential to bind strongly to the protein which the novel coronavirus uses to enter human cells and may prevent infection.
The study, published in the journal Virology, noted that a food-grade antibacterial small protein (peptide) called nisin, which is used globally as a safe and natural food-preservative, has the potential to bind to the ACE2 receptor in humans (hACE2) which the coronavirus uses to enter and infect cells.
The peptide nisin has the potential to bind to the human ACE2 receptor with higher efficiency than the spike protein of the novel coronavirus SARS-CoV-2,- study co-author Swadesh Ranjan Biswas from Visva-Bharati University in Kolkata told PTI.
Based on the findings, the scientists believe the peptide can potentially eliminate the interaction of the spike protein of the novel coronavirus with the human ACE2 receptor, and thereby control infection.
“Compared to the Receptor Binding Domain (RBD) of viral spike protein, nisin binds with the hACE2 receptor with higher affinity,” the researchers wrote in the study.
Commenting on the findings, Vigneshwar Ramakrishnan, professor of Bioinformatics at SASTRA University in Tamil Nadu, who was unrelated to the study, said “it is interesting and exciting to note that the food preservative nisin has the potential to bind to hACE2 receptor, and can competitively inhibit the binding of the RBD of the SARS-CoV-2.”
Repurposing existing drugs against diseases has garnered the attention of the scientific community for obvious reasons. However, as the authors note as well, several experimental studies need to be performed to confirm, in addition to strategizing doses and routes of administration,” Ramakrishnan told PTI.
In the research, Biswas and his team found that a unique culture of the bacterium Lactococcus lactis, widely used for cheese manufacturing, is capable of converting milk to curd and nisin.
Since nisin is a heat-stable natural food-grade peptide, Biswas believes it can be produced cost-effectively, even in large quantities using microbial fermentation.
The researchers added that the peptide can also be stored and transported without microbial contamination, since nisin has a strong antimicrobial action.
However, the scientists said more experiments are needed to determine its doses and application mechanism to check the competition of nisin and the spike protein of SARS-CoV-2 for accessing the ACE2 receptor in human cells.
The work encourages further research to take a similar approach in order to find other food peptides and food-grade natural small molecules for blocking the human ACE2 receptor,” Biswas added.