Intrinsically Disordered Proteins as an Instrument for Research-Integrating Teaching

Abstract

2,2,2-trifluoroethanol (TFE) as well as SAXS and 1-anilino-8-naphthalene sulphonate (ANS) binding supports a molten globule character. (b) The homology block 1 (HB1) domain of VAR2CSA (VAR2CSA 818–859 ) shows heterogeneity and oligomerization, as seen from the very few peaks in the NMR spectrum and the diversity of peaks originating from the single tryptophan (see figure insert). Addition of crowding agents as polyethylene glycol led to disappearance of the signals and fluorescence quenching, without visible precipitation. (c) A region of the intracellular domain of interleukin 22 receptor A1 (IL22RA1 L447–L532 ) was confirmed to be disordered by NMR and circular dichroism, with distinct cis - trans isomerism. (d) A lipidated, disordered C-terminal tail of KRAS form oligomers leading to broad peaks in the 1 H-NMR spectrum, that can be partly resolved by sodium dodecyl sulfate addition, but with an increasing SAXS Kratky plot indicating the presence of remaining disorder. (e) The N-terminal domain of galectin 3 is disordered as evidenced by the low dispersion in the 15N-HSQC and the increasing SAXS Kratky plot. NMR data indicate that it binds lactose and galactose very weakly at low pH. (f) The NMR signals of dehydrin Rab16c shows a low dispersion in the 15 N-HSQC spectrum, indicative of disorder, and elutes in two populations on a Sephadex S75 column, corresponding in sizes to the presence of a monomer–dimer equilibrium. The results presented in this figure are all preliminary data and would need repetition and validation.