When they dissolved samples of the peptide (RSAIEDLLFDK) in acidic solution (PH 3) they didn’t see the fibrillar structures (top left). Instead, they saw what they referred to as ‘globular structures’ that are consistent with disordered (peptide) monomers in solution. When they increased the pH just by 1 to pH = 4, they saw amyloid structures or fibrils. They refer to these structures as extended amyloid structures or nanotapes. When they increased the pH to 5, they saw the peptide self-assemble ‘into wide nanotapes, up to 100 nm thick, which in some areas unbundle into ∼20 nm thick nanotapes’, as shown in the top right square. In a nutshell, they kept increasing the pH incrementally to see what effect it had on the formation of these fibrils or nanotape structures and saw clearly that there was a sweet spot for nanotape formation at pH = 4-5.
So let’s back-up. They claim in the very first sentence of the paper that:
The sequence RSAIEDLLFDKV is found in many coronaviruses including the human common cold coronavirus spike protein as well as other coronavirus spike proteins from other animals.
I thought a little about the implications of this. Again, this is a materials science paper and they really care about the potential applications for ‘pH-triggered gels and/or for slow release applications’. But, what I still don’t know is: does the modified mRNA in the Pfizer and Moderna injections encode amyloidogenic peptides that result in the formation of nanotapes and amyloids under certain chemical/physiological conditions? And this brings me back to one of the most important question I posed well over a year ago and that is: ‘What are the resultant peptides of the modified mRNA following translation?’ (I Substacked about this (of course) and you can read that here.)
If the modified spike mRNA is not translated into its complete product by the host cells, and rather into incomplete ‘bits’ or peptides, then are any of these peptides amyloidogenic? Is it possible that one of these peptides is the analog peptide discussed here? Does that analog peptide (the conserved coronavirus SARS-nCoV-2 spike protein peptide) form amyloid nano-structures and hydrogels under pH-dependent (pH = 4) conditions? If so, where in the body could this happen? Could it happen? Stomach acid (pH = ~4)? Lysosomes (pH = ~4.5)8?
Just to be clear, it has been shown repeatedly in the literature that prion-like domains or peptides exist in the spike protein of SARS-nCoV-2 and these are specific to SARS-2.9 So again, what of our modified spike?