Quite often in biology, form will dictate function. That is to say, the structure of a molecule or protein will show us how it will act in the context of the human body. That is important because in science, we rely on physical structures of proteins + molecules to give us clues regarding their behavior and even more, the repercussions of those behaviors in the human body.
To get to the point, spike protein is something the SARS-CoV-2 virus uses to infect our cells which can cause many symptoms and side effects. Once infected, the body becomes a spike protein producing machine. Same thing with vaccinal spike protein-you’re inoculated then your body starts producing it. However, not all spike proteins are created equally nor do they affect the body the same way (natural spike from virus vs vaccine spike protein).
VACCINES: The goal of COVID-19 vaccines available in the USA is to get our bodies to recognize the spike protein on the outside of the SARS-CoV-2 virus (see picture above - spike protein is red). Essentially, the vaccines contain a code that enable our cells to produce spike protein and mount an immune response to it. That way in the future, if we come in contact with the virus, the immune system will be primed/trained on how to handle the infection.
NATURAL INFECTION: On the other hand, you could get exposure to the spike protein from being naturally infected. To be more specific, instead of using a code from a vaccine to produce spike protein, the invader forces the body to use its viral RNA (code) to produce the spike and all other viral parts.
💡In this medical publication, you will learn 2 things.
1️⃣ First, you will learn how the body normally produces spike protein as a result of natural SARS-CoV-2 - COVID-19 infection, and how the shape of those spike proteins determine their behaviors which ultimately delineate how they will act in the human body.
2️⃣ Second, conversely, you will learn how the body produces spike protein induced by mRNA, and viral vector vaccines like Pfizer, Moderna, and Johnson & Johnson and how their contrasting shapes change how they function in the body compared to naturally produced spike protein.
In order to understand the significance of everything previously explained, you first need to be educated on how the body becomes infected with COVID-19 then subsequently produces natural spike protein. The aforementioned will be explained using numbered bullet points and pictures. FIRST, PLEASE SEE THE ANATOMY OF A SPIKE PROTEIN IMMEDIATELY BELOW 👇🏻
▶️The anatomy of spike protein
Spike protein consists of 2️⃣ main segments S1 and S2 (see fig. 1 A)
The S1 segment is the head, the S2 segments contains the trunk (see fig. 1 A)
The entire spike is made up of 3 similar proteins together called trimer, more specifically homotrimer (see fig. 1 B - differences in color account for 3 major proteins - purple, blue, orange)
Those 3 proteins have 2 heads each (see fig 2.)
One of those heads is the RBD (RECEPTOR BINDING DOMAIN-green), the other head is the NTD (N-TERMINAL DOMAIN-blue) - both are used so the virus can attach to our cells (see fig. 2 B,C)
Also notice FURIN CLEAVAGE SITE, and S2 CLEAVAGE SITE. These are sites where our bodies use our own proteases (cellular scissors) to break apart the spike protein from the virus so it can begin infecting us. (fig. 3 C)
Now that you have seen the anatomy of spike protein, it is crucial to understand 2 important points. First, figures 1-3 are images of spike protein in a PRE-FUSION STATE. The next section will explain exactly what it means to be in a pre-fusion state. Second, further sections will explain exactly what it means when spike protein is in a POST-FUSION STATE. Continue on to read about how SARS-CoV-2 virus infects the body and makes cells produce natural spike protein.