Fig. 1: B-zyme enzymatically removed B-Ag from type B RBCs in kidney perfusate solutions.

a A schematic representation illustrating the enzymatic conversion of type B RBCs to type O RBCs (ECO) using B-zyme (α-galactosidase). The B allele encodes an α-1,3-galactosaminyltransferase (GTB), which transfers a galactose residue to the third position of the galactose in H-antigen, resulting in the formation of B-antigen. Accordingly, B-zyme hydrolyzes the α-1,3-galactose in the structure of B-Ag will result in exposure of the H-Ag. b Histograms illustrating B-Ag expression on RBCs treated with different doses of B-zyme in kidney perfusate solutions (UW, HTK, Celsior, and KPS-1) with 250 mM glycine at RT or 4 °C for 60 min. Positive control represents untreated type B RBCs, and negative control represents type O RBCs. c Heat map summary comparing the rate of B-Ag removal in different kidney perfusate solutions at RT or 4 °C for B-zyme-treated RBCs (n = 3). d Histograms showing B-Ag expression on RBCs treated with different doses of B-zyme in HD-40 solution (mixture of HTK, Glycine, and Dextran-40) at RT or 4 °C for 60 min. Positive control is untreated type B RBCs, and negative control is type O RBCs. e Heat map summary comparing the rate of B-Ag removal in HD-40 solution at RT or 4 °C for B-zyme-treated RBCs (n = 3). Data are presented as mean ± SEM, analyzed using two-way analysis of variance (ANOVA) followed by Bonferroni’s multiple comparisons test. ns, no significance. Source data are provided as a Source Data file. H-Ag H antigen, B-Ag B antigen, RBCs red blood cells, ECO enzyme converted O, UW University of Wisconsin, HTK histidine-tryptophan-ketoglutarate, KPS-1 kidney perfusion solution, Ctrl control, RT room temperature.