The genetic recombination of the SARs-CoV-2 virus in bats may result in behaviors comparable to those of certain RNA viruses. This cross-activity helps explain SARs-CoV-2's strange respiratory symptoms and immune evasion abilities. In this present study, the biological roles of SARs-CoV-2 proteins were investigated utilizing bioinformatic techniques involving the search for conserved domains. According to the study, the S and ORF3a proteins of SARs-CoV-2 possess picornavirus/calicivirus capsid domains, can bind hemoglobin, heme, and porphyrin. Both Arg134 of ORF3a and Cys44 of E are iron-binding sites for heme. The ORF3a protein has a region that converts heme into iron and porphyrin. In addition to chitin and polyphenol binding domains, the S protein also contains hemocyanin and phenoloxidase-like domains. The S protein constructs Fe-polyphenol complexes to link the red blood cell membrane, allowing SARs-CoV-2 to hitch a ride on red blood cells for fast delivery to target organs. This type of capsid-like vector delays the immune system but does not significantly alter the function of red blood cells to transport oxygen. Due to the distortion of the cell membrane, red blood cells with an excess of viral particles release hemoglobin to harm the virus. The wbl domains of the S protein respond to nitration, and then phenoloxidase domains oxidize polyphenols, allowing the virus to shed from the red blood cell membrane. ORF3a also attack 1-beta chain of hemoglobin; however, the majority of hemoglobin may retain its native structure. Patients will have variable degrees of respiratory distress and coagulation symptoms, but the hemocyanin domains of the S protein can improve a patient's respiratory status by transporting oxygen.
1. Supplemented evidence literature and calculation results according to reviewers' comments. 2. Rewrote the abstract and conclusion and supplemented the content of the background, results, and discussion. 3. The basic conclusion remains unchanged: the viral protein will attack the 1-beta chain of hemoglobin; combine with heme, and decompose heme. 4. New discovery: The way viral proteins attack hemoglobin is to protect the virus's capsid-like vector. This "free-rider" strategy on red blood cells enables rapid delivery to organs of interest, and finishes immune delay and escape.