Enzymes are biological molecules that speed up chemical reactions in the body. Some of the enzymes that can break down spike proteins are:
• Proteases:
These are enzymes that break down proteins into smaller fragments called peptides or amino acids. Proteases can cleave the bonds between the amino acids that make up the spike protein, and thus reduce its ability to bind to the human ACE2 receptor. Some examples of proteases are pepsin, trypsin, chymotrypsin, and furin. https://www.healthline.com/nutrition/proteolytic-enzymeshttps://www.healthline.com/health/protein-digestion
• Bromelain:
This is an enzyme that is found in pineapple stems and juice. It can also break down proteins and glycoproteins, which are proteins with sugar molecules attached to them. The spike protein is a glycoprotein, and bromelain can cleave its sugar chains and disrupt its structure. Some studies have suggested that bromelain can reduce the infectivity of the coronavirus by preventing it from binding to the ACE2 receptor. Note this study uses cell cultures and artificial membranes.
Bromelain inhibits SARS‐CoV‐2 infection via targeting ACE‐2, TMPRSS2, and spike protein
• N-acetylcysteine (NAC):
This is a compound that is derived from the amino acid cysteine. It is not an enzyme itself, but it can help other enzymes to break down proteins and mucus. NAC can also reduce the disulfide bonds that hold together the spike protein and make it more stable. Some studies have suggested that NAC can enhance the effects of bromelain and other proteases on the spike protein and reduce its infectivity. It should be noted that this study is in vitro (in a petri dish) and is not the same as a medical trial.
The Combination of Bromelain and Acetylcysteine (BromAc) Synergistically Inactivates SARS-CoV-2
• Nattokinase:
Nattokinase is an enzyme found in natto, a meal made from fermented soybeans that is popular in Japan. Some studies have suggested that nattokinase can degrade the spike protein and reduce the infectivity of the coronavirus by preventing it from binding to the human ACE2 receptor. These studies were done in vitro, meaning in a laboratory setting outside of a living organism. A limitation of nattokinase is the low bioavailability, meaning that while it performs well outside the body it does not absorb particularly well from the stomach into the bloodstream.
Degradative Effect of Nattokinase on Spike Protein of SARS-CoV-2
Supercomputer Modelling
Two examples of natural compounds which were predicted by supercomputers to be beneficial to support the normal functioning of the body are Quercetin and Thymoquine (from Black Cumin Seed.) These predictions were based on the knowledge that the spike protein would attempt to enter cells through the ACE2 receptor site, so natural compounds were sought to interfere with this process.
References:
https://chemrxiv.org/engage/chemrxiv/article-details/60c74980f96a00352b28727c
https://www.researchgate.net/publication/340429318_Identification_of_Compounds_from_Nigella_Sativa_as_New_Potential_Inhibitors_of_2019_Novel_Coronasvirus_Covid-19_Molecular_Docking_Study