<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bergfeld, Anne K.</style></author><author><style face="normal" font="default" size="100%">Lawrence, Roger</style></author><author><style face="normal" font="default" size="100%">Diaz, Sandra L.</style></author><author><style face="normal" font="default" size="100%">Pearce, Oliver M. T.</style></author><author><style face="normal" font="default" size="100%">Ghaderi, Darius</style></author><author><style face="normal" font="default" size="100%">Gagneux, Pascal</style></author><author><style face="normal" font="default" size="100%">Leakey, Meave G.</style></author><author><style face="normal" font="default" size="100%">Ajit Varki</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">N-glycolyl groups of nonhuman chondroitin sulfates survive in ancient fossils</style></title><secondary-title><style face="normal" font="default" size="100%">PNAS</style></secondary-title><short-title><style face="normal" font="default" size="100%">Proceedings of the National Academy of Sciences</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2017</style></year><pub-dates><date><style  face="normal" font="default" size="100%">09/2017</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.pnas.org/content/early/2017/09/05/1706306114</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;Biosynthesis of the common mammalian sialic acid&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;N&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;-glycolylneuraminic&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt; acid (Neu5Gc) was lost during human evolution due to inactivation of the&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;CMAH&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;&amp;nbsp;gene, possibly expediting divergence of the&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;Homo&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;&amp;nbsp;lineage, due to a partial fertility barrier. Neu5Gc catabolism generates&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;N&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;-glycolylhexosamines&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;, which are potential precursors for glycoconjugate biosynthesis. We carried out metabolic labeling experiments and studies of mice with human-like Neu5Gc deficiency to show that Neu5Gc degradation is the metabolic source of UDP-GlcNGc and UDP-GalNGc and the latter allows an unexpectedly selective incorporation of&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;N&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;-glycolyl&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt; groups into chondroitin sulfate (CS) over other potential glycoconjugate products. Partially&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;N&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;-glycolylated-CS&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt; was chemically synthesized as a standard for mass spectrometry to confirm its natural occurrence. Much lower amounts of GalNGc in human CS can apparently be derived from Neu5Gc-containing foods, a finding confirmed by feeding Neu5Gc-rich chow to human-like Neu5Gc-deficient mice. Unlike the case with Neu5Gc,&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;N&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;-glycolyl-CS&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt; was also stable enough to be detectable in animal fossils as old as 4 My. This work opens the door for investigating the biological and immunological significance of this glycosaminoglycan modification and for an “ancient glycans” approach to dating of Neu5Gc loss during the evolution of&amp;nbsp;&lt;/span&gt;&lt;em style=&quot;margin: 0px; padding: 0px; border: 0px; outline-style: none; font-size: 14px; font-family: Arial, sans-serif; line-height: inherit; text-align: justify; vertical-align: baseline; color: rgb(51, 51, 51);&quot;&gt;Homo&lt;/em&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: Arial, sans-serif; font-size: 14px; text-align: justify;&quot;&gt;.&lt;/span&gt;&lt;/p&gt;
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