Hypothesis Article: Food Proteins are a Potential Resource for Mining
Cathepsin L Inhibitory Drugs to Combat SARS-CoV-2
The entry of SARS-CoV-2 into host cells proceeds by a two-step
proteolysis process, which involves the lysosomal peptidase cathepsin L.
Inhibition of cathepsin L is therefore considered an effective method to
prevent the virus internalization. Analysis from the perspective of
structure-functionality elucidates that cathepsin L inhibitory
proteins/peptides found in food share specific features: multiple
disulfide crosslinks (buried in protein core), lack or low contents of
α-helix structures (small helices), and high surface hydrophobicity.
Lactoferrin can inhibit cathepsin L, but not cathepsins B and H. This
selective inhibition might be useful in fine targeting of cathepsin L.
Molecular docking indicated that only the carboxyl-terminal lobe of
lactoferrin interacts with cathepsin L and that the active site cleft of
cathepsin L is heavily superposed by lactoferrin. Food protein-derived
peptides might also show cathepsin L inhibitory activity.