Month: September 2022

PRIONS, INFECTIOUS PARTICLES. "The term "prion" is derived from proteinacious infectious particle and refers to the pathogen that causes transmissible spongiform encephalopathies (TSEs). This small infectious particle is a disease-causing form of a protein called cellular prion protein (PrPc). PrPc is mainly found on the surface of cells in the central nervous system, but it is also located in other bodily tissues." https://lnkd.in/e6wAxB5 View in LinkedIn

PRIONS, ABNORMALLY FOLDED PROTEINS. "A prion is composed of abnormally folded protein that causes progressive neurodegenerative conditions. These mis-folded proteins do not multiply in the host organism that they infect. Instead, they affect the brain structure by acting as a template, inducing proteins with normal folding to convert to the abnormal prion form." https://lnkd.in/e6wAxB5 View in LinkedIn

PRIONS TEMPLATE NORMAL PROTEINS. "These newly formed mis-folded proteins, in turn, act as further templates for the conversion of more normal proteins, leading to an exponential accumulation of prions in the tissue of the central nervous system. These abnormally folded proteins form plaques which are thought to cause "entanglement" of neurofibrils and interfere with synapse function." https://lnkd.in/e6wAxB5 View in LinkedIn

ROGUE PROTEIN ISOFORMS. "The best-known attribute of the prion protein (PrP) is its tendency to misfold into a rogue isoform. Neurodegeneration in prion disease is often seen as a consequence of abnormal PrP function yet, amazingly little is known about the normal, physiological role of PrP. In particular, the absence of obvious phenotypes in PrP knockout mice has prevented scientists from answering this important question." https://lnkd.in/eBQR5Bd View in LinkedIn

DNA INDEPENDENT. "Prion diseases are caused by conversion of a normal cell-surface glycoprotein (PrPC) into a conformationally altered isoform (PrPSc) that is infectious in the absence of nucleic acid." https://lnkd.in/eJBJ5gT View in LinkedIn

"THE TWO ISOFORMS of the PrP protein are technically designated PrPC and PrPSc. The "C" stands for cellular; the "Sc" stands for scrapie. PrPSc is believed to be the main, and probably the only, component of the prion (a term derived from "proteinaceous infectious particle")." https://lnkd.in/ekPJGXx View in LinkedIn

NORMAL PRION PROTEIN ISOFORMS. "PrP is a perfectly normal protein produced by nerve cells. When the cell needs more PrP protein, the gene that codes for PrP gets "turned on" and a new PrP molecule is synthesized. Inside the cell, PrP gets folded into its normal three-dimensional configuration. It's then excreted and anchored to the outside of the nerve cell, where it is believed to play a role in synaptic function." http://www.strangehorizons.com/2004/20040216/killer.shtml View in LinkedIn

SAFE NORMAL PRION PROTEIN ISOFORM. "If you happen to eat some PrP, it will be denatured by the cooking heat, then chopped up by enzymes in your digestive system. Tomorrow, its leftover bits will be flushed away -- literally. No harm done." http://www.strangehorizons.com/2004/20040216/killer.shtml View in LinkedIn

TOXIC ISOFORM (PRION). "Now: don't change the gene that codes for PrP. Don't even change the sequence of amino acids that make up the protein. Just take that perfectly normal PrP protein and tweak the 3-D structure a bit -- uncoil some of the helices and re-fold them into flat sheets. Chemically and genetically, this new PrP is identical to the old one. It's simply shaped differently, like a person who has changed from a sitting to a standing position. It's a new "isoform": different in physical appearance but not in genetic or chemical makeup. Don't eat this one." http://www.strangehorizons.com/2004/20040216/killer.shtml View in LinkedIn

INFECTIOUS PRION. "If you ingest a prion, it may not be "flushed away" the next morning. It's capable of crossing some species barriers. It's resistant to food-preparation treatments such as high heat and ultraviolet irradiation. It's stubbornly insoluble. And it knows how to find its way from your digestive system into your nervous system." http://www.strangehorizons.com/2004/20040216/killer.shtml View in LinkedIn