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1

It is not theoretically impossible for protein to self-replicate. It just did not evolve to be a common mechanism. Lee et al. 1996 reports finding of a protein that can catalyze its own synthesis.


0

It is possible indirectly in case of prion.See this link


12

Proteins can move around the membrane. The protein does move: the membrane is a liquid crystal and has fluid behaviour. Specifically this is due to the membrane being in a gel-state. This gel state allows phase behaviour which means that the protein is able to move around on the surface by a similar process. This is often referred to as the fluid mosaic ...


0

Like other forms of amyloid, aggregated prions form a beta-sheet structure, where individual beta-strands are linked together by hydrogen bonds between their extended peoptide backbones, and hydrophobic interactions between the side chains on either side of the peptide backbone. The beta-strand at each end of the beta-sheet has unpaired hydrogen bonds and ...


0

It is thought that infectious prions exist as clusters forming a crystalline structure. When a protein with the same primary structure is encountered but with a different tertiary structure, the normal protein undergoes a conformational change in order to integrate into the cluster. Presumably there are molecular forces involved that induce the ...


3

Yes. The 'order' of amino acids is the protein sequence, also known as the primary structure. A peptide (short protein) with sequence XYXYXYXYX is very different from XXXXXXXYYYYYYY. Your example is a bit trickier, since it seems like AB should be roughly equal to BA. However, each amino acid has two ends - the amino and carboxyl - and so a dipeptide like ...


0

if you sequence deep enough and add single-cell sequencing you will also find cell to cell differences in the DNA which will add an other layer of heterogeneity in protein expression between cells.


1

Remember that the concentrations you report are in mass units rather than mole units. If the protein has a mass of 40,000 Da, reasonable for many proteins, then 20 mg/liter means $0.5$ x $10^{-6}$ mol/liter. A typical small-mass product of an enzyme reaction might have a mass about 200, so its apparently lower mass concentration of 2 mg/liter is $10$ x ...



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