The Atlantic reports:

Twenty-nine. That’s the number of proteins the new coronavirus has, at most, in its arsenal to attack human cells. That’s 29 proteins to go up against upwards of tens of thousands of proteins comprising the vastly more complex and sophisticated human body. Twenty-nine proteins that have taken over enough cells in enough bodies to kill more than 80,000 people and grind the world to a halt.

If there is a way—a vaccine, therapy, or drug—to stop the coronavirus, it will be by blocking these proteins from hijacking, suppressing, and evading humans’ cellular machinery. The coronavirus may sound small and simple with its mere 29 proteins, but that is also what makes it hard to fight. It has so few weak spots to exploit. Bacteria, in comparison, might have hundreds of their own proteins.

Scientists have been furiously looking for a weakness in SARS-CoV-2, as the coronavirus that causes COVID-19 is formally known, ever since it was identified as the culprit behind mysterious pneumonia cases in Wuhan, China, in January. In just three months, labs around the globe have homed in on individual proteins, mapping some of their structures atom by atom at a record pace. Others are screening molecular libraries and the blood of COVID-19 survivors for compounds that can tightly bind and inhibit these viral proteins. More than 100 existing and experimental drugs are being tested against COVID-19. A vaccine candidate from Moderna was first injected into the arm of the first volunteer in mid-March.

Yet other researchers are focusing on how these 29 proteins interact with parts of the human cell—with the goal of finding drugs that target the host instead of the virus. While this seems indirect, it follows with the replication cycle of viruses. Unlike bacteria, viruses cannot copy themselves. “Viruses use the machinery of the host,” says Adolfo García-Sastre, a microbiologist at the Icahn School of Medicine at Mount Sinai. They trick host cells into copying their viral genomes and making their viral proteins. [Continue reading…]