The protease inhibitors in soy protein, such as trypsin inhibitors and soy antigen proteins, are key endogenous hydrolytic enzymes, protease A1, and peptidases, involved in soybean germination. When the anti trypsin inhibitor is combined with pepsin and trypsin, the former has higher proteolytic enzyme activity and stronger stress resistance, and can degrade animal digestive enzymes instead of being degraded by them. The capsid proteins of various viruses are proteases. After binding to membrane protein receptors, the capsid protein degrades the membrane protein, causing damage to cell integrity and initiating the endocytosis mechanism, or make a crack in the cell membrane. The destroyed membrane protein, including the virus, is internalized to form intracellular vesicles, initiating the virus infection mechanism. A virus is a protease encapsulated by DNA/RNA, which helps DNA/ RNA enter host cells for replication and proliferation. The immune response is an enzymatic reaction that defends against internal proteases with viral proteases, and is a reaction between Ab proteases and Ag proteases, so the antibodies specificity appears to be high. Hormones like insulin works as protease too. Animal protease and virus protease are synthesized in the form of proenzymes. Animals and human beings themselves have almost no diseases. The diseases such as cancer, hypertension, stroke, diabetes and obesity may be caused by universal vaccination. Widespread vaccination leads to excessive activity of antibody proteases in the body, disrupting the normal mechanism of regulating protease levels. If vaccination is stop, as the source of infectious diseases is well controlled, humans will not have mass outbreaks of the above diseases. The article presents some insights into digestive physiology and preventive medicine.
