Fig. 2: Experimental characterization of designed single-helix heterotrimers.
From: De novo design of obligate ABC-type heterotrimeric proteins
a, Colored cross-sections across the coiled coil heterotrimer (DHT01) show core packing across the inner five heptads making up the shared ABC interface, with hydrogen bond networks and hydrophobic packing highlighted. b, Design models of DHT01 and two four-arm fusions, colored by chain (dark gray for chain A, blue for chain B and magenta for chain C) and shown in cartoon representation. c, Superose 200 chromatograms and SDS-PAGE gels (inset, with the locations of molecular weight markers) for DHT01 (top), DHT01-4arm-01 (middle) and DHT01-4arm-02 (bottom), showing three chains eluting at a monodisperse peak. d, nMS results for DHT01 (top), DHT01-4arm-01 (middle) and DHT01-4arm-02 (bottom), showing only the ABC heterotrimer forming. MW, molecular weight. e, SAXS profiles for DHT01 (top), DHT01-4arm-01 (middle) and DHT01-4arm-02 (bottom), indicating a good quality of fit (χ) between the respective design models (red lines) and experimental data collected (black dots). f, Circular dichroism spectra for DHT01 (top), DHT01-4arm-01 (middle) and DHT01-4arm-02 (bottom) at 25 °C (black), 75 °C (blue) and 95 °C (pink) before cooling and after cooling to 25 °C (gray), with thermal melting curves (inset) measured at 222 nm. MRE, mean residue ellipticity. Uncropped gel images for c are available as source data.
