text: user12686: What does it mean by "PC" in this article?
  
  a fast and efficient Cα-based method for accurately assigning protein secondary structure elements
  
  
  
  user73: Answer from @user438383, @matteo-ferla and @m, converted from comments [anyone, feel free to edit this answer to improve it]:
  According to the intro it means 'pseudocenter'. All measurements are relative to an assigned point because a protein doesn't have a 'centre' they assigned it as a pseudocentre.
  Note that PC normally means principal component, but that does not seem to be the case here.
  
original_text: 12686: <p>What does it mean by &quot;PC&quot; in this article?</p>
  <ul>
  <li><a href="https://pubmed.ncbi.nlm.nih.gov/24995959/" rel="nofollow noreferrer">a fast and efficient Cα-based method for accurately assigning protein secondary structure elements</a></li>
  </ul>
  <p><a href="https://i.stack.imgur.com/h7JCE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/h7JCE.png" alt="enter image description here" /></a></p>
   73: <p><em>Answer from @user438383, @matteo-ferla and @m, converted from comments [anyone, feel free to edit this answer to improve it]:</em></p>
  <p>According to the intro it means 'pseudocenter'. All measurements are relative to an assigned point because a protein doesn't have a 'centre' they assigned it as a pseudocentre.</p>
  <p>Note that PC normally means principal component, but that does not seem to be the case here.</p>
  