The components of the 720 kDa complex were identified using mass spectrometry. Proteins are arranged according to the values of the exclusive spectrum count (Spec.)/exclusive unique peptide count (Pep.). This ratio reflects the relative molar ratio of each peptide. The top seven proteins are listed because the seventh protein, the GABAAR α6 subunit, is a major component of the 500 kDa, but not 720 kDa, GABAAR complex. Detailed peptide information is provided in the Table S1.