<story><title>Deadly animal prion disease appears in Europe</title><url>http://www.nature.com/news/deadly-animal-prion-disease-appears-in-europe-1.19759</url></story><parent_chain><item><author>shmageggy</author><text>Prions are a crazy, crazy phenomenon. From wikipedia:&lt;p&gt;&amp;gt; &lt;i&gt;A protein as a standalone infectious agent stands in contrast to all other known infectious agents such as viruses, bacteria, fungi, and parasites, all of which contain nucleic acids (DNA, RNA, or both)&lt;/i&gt;&lt;p&gt;In my layman&amp;#x27;s understanding, they&amp;#x27;re like this bizarre edge case in the way proteins interact. Of all the myriad way a protien can fold, it happens to find one that &lt;i&gt;induces the same malformation&lt;/i&gt; when it interacts with another protein. To me, it almost seems like as much of a mathematical&amp;#x2F;geometrical problem as a biological one. In any case, very interesting from the perspective of emergent behavior in complex systems.</text></item></parent_chain><comment><author>matthewmcg</author><text>Right--as I understand it, it&amp;#x27;s not that different than Google&amp;#x27;s &amp;quot;Meeting Room Hardware Virus&amp;quot;:&lt;p&gt;&amp;quot;I imagine it started with all of the adapters which were thrown around in every meeting room. Everyone with a Macbook of some flavor needed a DVI to VGA adaptor in order to use the projectors, so they were plentiful. Somehow, someone probably damaged one of them and smooshed a couple of pins into places where they should not have gone.&lt;p&gt;&amp;quot;Then, someone else forced this into their Mac. Perhaps two pins tried to go into just the one socket. At any rate, it would now break the socket and get it all out of whack. That socket, used with another adapter in another room, would then break that adapter. This new broken adapter would then go on to break even more Macbook DVI connectors.&lt;p&gt;Thus, we had a hardware virus.&amp;quot; [1]&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;rachelbythebay.com&amp;#x2F;w&amp;#x2F;2012&amp;#x2F;09&amp;#x2F;24&amp;#x2F;dvi&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;rachelbythebay.com&amp;#x2F;w&amp;#x2F;2012&amp;#x2F;09&amp;#x2F;24&amp;#x2F;dvi&amp;#x2F;&lt;/a&gt;</text></comment>
<story><title>Deadly animal prion disease appears in Europe</title><url>http://www.nature.com/news/deadly-animal-prion-disease-appears-in-europe-1.19759</url></story><parent_chain><item><author>shmageggy</author><text>Prions are a crazy, crazy phenomenon. From wikipedia:&lt;p&gt;&amp;gt; &lt;i&gt;A protein as a standalone infectious agent stands in contrast to all other known infectious agents such as viruses, bacteria, fungi, and parasites, all of which contain nucleic acids (DNA, RNA, or both)&lt;/i&gt;&lt;p&gt;In my layman&amp;#x27;s understanding, they&amp;#x27;re like this bizarre edge case in the way proteins interact. Of all the myriad way a protien can fold, it happens to find one that &lt;i&gt;induces the same malformation&lt;/i&gt; when it interacts with another protein. To me, it almost seems like as much of a mathematical&amp;#x2F;geometrical problem as a biological one. In any case, very interesting from the perspective of emergent behavior in complex systems.</text></item></parent_chain><comment><author>nonbel</author><text>&amp;gt;&amp;quot;Of all the myriad way a protien can fold, it happens to find one that induces the same malformation when it interacts with another protein.&amp;quot;&lt;p&gt;It doesn&amp;#x27;t really &amp;quot;just happen&amp;quot;, amyloids consist of peptides folded into beta-sheets and aggregates of these seem to be the most thermodynamically stable structures it is possible for polypeptide chains (regardless of sequence) to form:&lt;p&gt;&amp;quot;From a wide range of in vitro experiments on peptides and proteins we now know that the formation of amyloid structures is not a rare phenomenon associated with a small number of diseases but rather that it reflects a well-defined structural form of the protein that is an alternative to the native state — a form that may in principle be adopted by many, if not all, polypeptide sequences&lt;p&gt;[...]&lt;p&gt;These observations, therefore, have led to the remarkable conclusion that, at the concentrations present in living systems, the native states may not always represent the absolute free energy minima of the corresponding polypeptide chains — the native form of a protein could in some cases simply be a metastable monomeric (or functionally oligomeric) state that is separated from its polymeric amyloid form by high kinetic barriers&amp;quot;
&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.ncbi.nlm.nih.gov&amp;#x2F;pubmed&amp;#x2F;24854788&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.ncbi.nlm.nih.gov&amp;#x2F;pubmed&amp;#x2F;24854788&lt;/a&gt;&lt;p&gt;Edit:&lt;p&gt;I realized some people might not be aware of the connection to prions. Here it is from the same wikipedia page as cited by the parent:&lt;p&gt;&amp;quot;All known prions induce the formation of an amyloid fold, in which the protein polymerises into an aggregate consisting of tightly packed beta sheets.&amp;quot;
&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Prion&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Prion&lt;/a&gt;</text></comment>