Fig. 2

Analysis of LLPS properties of HBP-1 N- and C- terminal variants and peptides. a Amino acid sequence representation of HBP-1 protein. The repetitive region (G67–G145) is presented with modular repeats indicated with different color shades for motifs containing His (blue) or hydrophobic residues (red), and for the GHGLY motif (green). Non-repetitive N- and C-terminal regions are marked in gray. b C-terminal variants (V1-C containing the whole repetitive region, and V2-C truncated at position G98). c N- and C- variants obtained by trypsin cleavage. d Synthetic peptides. The same color marking was used for all peptides shown. Full amino acid sequences of all proteins and peptides are presented in Supplementary Figs. 1 and 7. Region of the HBP-1 sequence indicted in brackets. Variants that undergo LLPS marked with *. e Phase diagrams (protein or peptide concentration (C) on x-axis and pH on y-axis) at low (0.1 M) and high (1 M) salt concentrations, illustrating the conditions required to induce LLPS. As indicated in the upper-left panel (HBP-1), at low protein concentration only one phase is present (soluble protein). When LLPS occurs two phases co-exist, i.e. protein rich phase (coacervate microdroplets/hydrogel) and protein depleted diluted phase (the boundary lines between two phases are drawn as a guide for the eye). Black empty dots indicate pH and protein concentration at which optical micrographs presented in panel (f) were obtained. Source data are provided as a Source Data file. f Examples of optical micrographs taken after LLPS of all the variants and peptides described above and of HBP-1 (used as a control). Micrographs of V5-N, V6-N and V7-N represent hydrogels.