Does protein-protein interaction only happens when one of them is basic and the other acidic? Do protein interactions also depend on the protein structure? Are there more factors?

  • $\begingroup$ Proteins are not acidic or basic per se. It depends on the environment - if this is acidic, than some aminoacids can be protonated, while others cannot. But in a given environment proteins are either acidic or basic, but not both. $\endgroup$
    – Chris
    Apr 21, 2015 at 7:29
  • $\begingroup$ so two acidic proteins can interact in an environment? $\endgroup$
    – girl101
    Apr 21, 2015 at 7:37
  • $\begingroup$ Yes. Acidity or basicity of a protein is an overall property. What's important is the charge of residues at the interface where the proteins interact (amongst other things). $\endgroup$
    – canadianer
    Apr 21, 2015 at 8:15
  • $\begingroup$ what are the other things? $\endgroup$
    – girl101
    Apr 21, 2015 at 8:17
  • $\begingroup$ Your question seems too broad and dupllcates these: biology.stackexchange.com/questions/2965/…, biology.stackexchange.com/questions/1404/… $\endgroup$
    – Mithoron
    Apr 22, 2015 at 11:08

1 Answer 1


It depends both on structure and charge. Binding sites of proteins are essentially formed by amino acids placed in a particular conformations such that it will match the binding site of their counterpart protein or substrate. This is commonly referred to as the lock and key model of protein binding. This is similar to how two puzzle pieces fit together, the pieces are exactly the same shape at the point at which the puzzle pieces connect. At a protein binding site amino acids are clustered together to form the matching shape to the appropriate binding partner. This however is not just dictated by 'physical shape' of each amino acid but also their charges. This is important because negatively charged amino acids will repel other negatively charged amino acids, and attract to positive amino acids, thereby modulating the exact 'shape' of the protein binding site.

  • $\begingroup$ so negative;y charged amino acid will bind to positively charged amino acid. Similarly cant we say the same for proteins as a whole? $\endgroup$
    – girl101
    Apr 22, 2015 at 4:05
  • $\begingroup$ apart from charge and structure, is there any other feature on which the binding depends?? $\endgroup$
    – girl101
    Apr 22, 2015 at 4:19
  • $\begingroup$ so the charge in the binding site of protein is being considered for binding and not the entire charge of the entire protein. Am I right? $\endgroup$
    – girl101
    Apr 22, 2015 at 4:29
  • $\begingroup$ Yes you are correct. $\endgroup$ Apr 22, 2015 at 14:53

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