Description:
<jats:p>Polyglutamine tract‐binding protein 1 (PQBP1) is an intrinsically disordered protein abundantly expressed in the brain. Mutations in the <jats:italic>PQBP1</jats:italic> gene are causative for X‐linked mental retardation disorders. Here, we investigated the structure of the C‐terminal segment within the context of full‐length PQBP1. We produced a segmentally isotope‐labeled PQBP1 composed of a non‐labeled segment (residues 1–219; N‐segment) and a <jats:sup>13</jats:sup>C/<jats:sup>15</jats:sup>N‐labeled segment (residues 220–265; C‐segment). Our results demonstrate that the segmental isotope‐labeling combined with NMR spectroscopy is useful for detecting a very weak intra‐molecular interaction in an intrinsically disordered protein.</jats:p>