pH-dependent compaction of intrinsically disordered poly-E motif in titin

Intrinsically disordered proteins and regions (IDPs/IDRs) have been found to play a role in a variety of cellular processes. Unlike ordered proteins, many IDPs become more structured under extreme pH conditions as a result of neutralization of the charged amino acids in the IDP. This occurs because a higher net charge per residue (NCPR) results in increased pH-dependent conformational change. However, the correlation between increased NCPR and increased pH sensitivity is variable between IDPs, suggesting that NCPR alone cannot explain the observed variation in pH sensitivity.