an><span  title="ProteinName" class="an ProteinName">Glu</span><span  title="" class="an ">&ensp;</span>persisted <span  title="" class="an ">&ensp;</span>in <span  title="" class="an ">&ensp;</span>the <span  title="" class="an ">&ensp;</span>absence <span  title="" class="an ">&ensp;</span>of <span  title="" class="an ">&ensp;</span>external <span  title="" class="an ">&ensp;</span><span  title="ProteinName" class="an ProteinName">Ca</span><span  title="" class="an ">&ensp;</span>but <span  title="" class