Polypeptide drugs: gatekeepers that block entry and exit of viruses into and out of cells

Current drug development against novel coronaviruses involves many directions in traditional Chinese medicine (TCM), chemotherapeutic small molecules, antibody drugs, and so on, while peptide drugs, due to their small molecular weight and easy synthesis, are also widely used in medicine, and today the small series continues to introduce IP innovation win and win "" anti disease series "" peptide antiviral drugs.

Polypeptides, which are biological small molecules composed of a variety of amino acids, have high activity and fewer side effects, and are good drug candidates, which have a wide range of applications in immune regulation, anti viral infection, and so on.

Turning to the mechanism of peptide drugs against viral infection, it also has to start with the process of viral infection.The virus can cause disease in humans and two conditions need to be met: first to enter human cells and then to reach a certain number.

Viruses generally contain an outer shell and genetic material.These genetic materials (ribonucleic acid RNA or deoxyribonucleic acid DNA) can be understood as instructions that prompt continued replication of the virus inside the cell.

Schematic representation of the structures of the various viruses

(the outer layer is the outer shell, and the portion of its inner curvature represents the gene)

Therefore, the key steps of virus infection are: 1. To penetrate the human cell membrane with an outer shell, 2. To release the genetic material into the cell, 3. To utilize the material and nutrients inside the human cell, to continuously replicate the virus according to the virus assembly manual, and 4. To release the replicated virus from the cell again, to infect more cells.(see [1] below.)

If left unchecked, the above processes continue to circulate, normal cells of the body are massively destroyed, leading to dysfunctional or lost organs, or the immune system produces an excessive response, which in turn triggers disease.

Understanding the principles of viral infection, can you still not generalize about such an idea of combating the virus?All together is a sentence: either let the virus "" go in "" or "" come out ""!

First say how is a polypeptide drug made "" inaccessible "" to viruses?

In the case of the SARS virus, there is a special protein structure on its surface - the S protein (bulge on the top), which, when brought into contact with a human target cell, enables viral polypeptide 1 and viral polypeptide 2 in the S protein to form "" six helices "" that act like a "" key "" to open the cell membrane (Fig. [2]).

So, if, through the synthesis of polypeptides similar to viral peptide 1 or viral peptide 2, the viral own polypeptides are disguised, competitively participate in the formation of the "" six helix bundle "", deforming it, the virus is unable to generate the correct "" key "".

Reported: there is a protein called "" ACE2 "" in human cells that misleads and destroys the limited "" key "" of the SARS virus as long as it is synthesized as a polypeptide fragment, which is equal to adding a "" lock "" to human cells, which inhibits the infection of the SARS virus.[3]

According to the results presented in the preprint of the biorxiv Life Sciences paper at MIT in March [4]: ACE2 protein was also used to enter human cells.Progress in the development of peptide drugs that inhibit the new corona virus is also reported here.The invasion of new coronaviruses will pose a potential threat to us.

In fact, leaky viruses always enter cells.So how can one leave the virus' out 'after replication?That's the second role a peptide drug can play.

Previously we have stated that viral genetic material (RNA or deoxyribonucleic acid DNA) is a "" guide "" for the virus to continuously replicate inside the cell.According to this "" guide, "" the completion of viral replication needs to go through the steps of gene transcription, translation (translation of the genetic "" code "" into protein), clipping, assembly, stabilization of the protein.

So, as long as at least one of these steps is broken, the replication of the virus can be interrupted, making it "" undruggable "".In each of the above steps, scientists have strived to develop corresponding polypeptide drugs in order to achieve defense against viruses.We believe that, in the near future, peptides against novel coronaviruses will emerge and that peptides will also play a greater role in the control of various viruses in the future.

For any requests of Peptide for research purpose, welcome to contact us. www.gtpeptide.com , sales1@gotopbio.com.