<span  title="" class="an ">&ensp;</span><span  title="ProteinName" class="an ProteinName">Glu</span><span  title="" class="an ">&ensp;</span>and <span  title="" class="an ">&ensp;</span><span  title="ProteinName" class="an ProteinName">aspartate</span><span  title="" class="an ">&ensp;</span>Asp <span  title="" class="an ">&ensp;</span>have <span  title="" class="an ">&ensp;</span>been <span  title="" class="an ">&ensp;</span>investigated <span  title="" class="an ">&ensp;</span>using <span  title="" class