Fig. 3: The key residues that mediate intermolecular N-terminal domain (NTD) interactions.

a Alignment of galectin-3 amino-acid sequences from different vertebrates (human, five mammals, one bird, one amphibian, and one fish). The phylogenetic tree is plotted based on a summary of multigene and multiprotein studies⁸⁷. Residues in the carbohydrate recognition domain (CRD) are highlighted with dark, medium, or light orange depending on their level of conservation. Negatively and positively charged residues, tyrosines, and tryptophans in the NTD are colored in red, blue, yellow and purple, respectively. b Amino-acid sequences of the constructs used in this study with negatively charged residues, tryptophans, and tyrosines highlighted by solid red, purple, and yellow circles, respectively. c NMR peak intensity ratios between 40 and 400 µM samples at 10, 20, and 30 °C for the four NTD constructs. The average peak intensity ratios at each temperature are shown in the right-most panel. Red dashed lines indicate the intensity ratio expected from the molar ratio (0.1). d Transverse relaxation rate constants for the 40 (black) and 400 (red) µM wild-type and WY/G mutants at 10 °C. e Micrographs of samples of wild-type galectin-3 and the WY/G construct under conditions corresponding to the two-phase regime in the wild-type phase diagram (Fig. 2e; scale bar: 50 µm). Experiments were performed at least three times for each protein sample.