If you’ve been following our posts on nervous system function or biological electronics, as we treat this field here at MilovanInnovation, you’ve become acquainted with the fundamental processes occurring at the level of nerve cells – neurons – and between them in biological switchboards and junctions – synapses.
The “executors” of these complex processes are proteins. We can best describe them in technical terms as an army of nanobots – nanometre-sized robots meticulously designed to perform specific functions.
Molecular Machine Factories and Blueprints ππ
The factories and workshops where these nanobots are manufactured in cells are called ribosomes. The blueprint for their construction is obtained by copying information from gene DNA chains. The sequence of bases in the DNA chain (and to recall, there are four bases total: adenosine, cytosine, guanine, and thymine) determines the amino acid sequence in the protein (nanobot) synthesized in the ribosomes.
Beyond the amino acid sequence, for protein “correctness,” it is crucially important how these amino acids are spatially arranged – that is, “folded.” Just like for a robot, besides the electrical schematic that provides the basic elements and their connection methods, how the robot’s axes are positioned and oriented is essential for it to perform its intended function.
The Dual Identity of Prions β οΈ
Prions are a type of protein found in nerve cells:
The Normal “Correct” Prion (PrP^C) β present in all vertebrates, particularly in nerve cells. Its function is not fully understood, but according to conducted research, it might be:
- Protecting nerve cells from stress
- Participating in memory?
- Regulating iron transport
The Pathogenic Form (PrP^Sc) β we know very well that these lead to truly the most terrifying nervous system diseases with 100% fatality in CJD (the human equivalent of “mad cow” disease) or Kuru.
Engineering Analysis of a Fatal Flaw π οΈπ
So, if everything is fine, we have a normal, correct protein: an ISO 9001 certified product. The pathogenic “defective” prion: same specification, defective manufacturing.
The problem is that these defects multiply and become dominant. We have a spreading mechanism: Molecular “tool contamination” β one defective part ruins all others. And we get an army of defective nanobots taking the place of the correct ones.
The cell normally possesses systematic error detection and quality maintenance mechanisms (chaperones, the ubiquitin-proteasome system that serves to eliminate defective proteins). Pathogenic prions overwhelm the quality maintenance mechanisms, like a DoS attack on the molecular network.
Neurological Consequences: Control System Collapse π§ π₯
Pathogenic prions act as noise in neuronal transmission. Accumulation of amyloid plaques in the brain mass occurs, causing:
- Loss of synaptic integrity (switchboard failure)
- Information flow congestion
The clinical pictures are terrifying – the patient loses not only control over their body but the entire control system – the entire neurological system with the brain simply stops functioning and shuts down.
Levinthal’s Paradox: Nature’s Greatest Engineering Challenge πβ
Prion diseases are the most eerie reminder of the importance of proper protein folding. And the mechanism for this folding is extremely complex and still not fully understood.
What we know is that protein folding, physically speaking, is movement through a multidimensional energy landscape:
- TheΒ global minimumΒ (energy) corresponds to the correctly folded state
- Local minimaΒ lead to erroneous conformations (pathogenic prions)
Engineering challenge: How to ensure the system always finds the global minimum?
Levinthal’s paradox β why folding is a miracle:
- A protein of 100 amino acids has ~10ΒΉβ°β° possible conformations
- To randomly try them all, it would need more than the age of the universe
- Conclusion:Β There must be a “signpost” β quantum tunneling through energy barriers?
Conclusion: Between Miracle and Fragility β¨
This story reminds us simultaneously how life is a great and incomprehensible miracle, a symphony of the most complex laws of quantum mechanics and chemistry, yet on the other hand so delicate and sensitive. How fragile and wonderful our existence is. And how much we still must study and research before we reach the secrets of the processes that make us conscious beings and that keep us alive.
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