Extended Data Fig. 4: Identification of a tyrosine-based cyclic peptide as a substrate for FIKK13.
From: The fast-evolving FIKK kinase family of Plasmodium falciparum can be inhibited by a single compound
a, Scheme of the FIKK13 RaPID selection. b, Sequences and binding affinities of the different peptides recovered after 6 rounds of selection and different variants of the parent peptides. Peptides were initialised with d-Tyr and cyclised via a thioether bond between the N-terminus and the cysteine side chain. Binding affinities were measured by SPR (Supplementary Table 9) and show average ± standard deviation of at least 2 independent replicates. c, FIKK13 kinase domain phosphorylating activity on cyclic peptide identified in panel b. The results are represented as the mean ± SEM fold change compared to the no substrate luminescent signal obtained using the ADP-Glo assay. Statistical significance was determined using a one-way ANOVA followed by Dunnett’s multiple comparison post-test (FIKK13_2 versus no substrate, p = 0.0421; FIKK13_3 versus no substrate, p = 0.9997; FIKK13_4 versus no substrate, p < 0.0001; FIKK13_5 versus no substrate, p = 0.9807). n = 3 biological independent replicates. d, FIKK13 kinase domain phosphorylating activity on FIKK13_4 mutant peptides. The results are represented as the mean ± SEM fold change compared to the no substrate luminescent signal obtained using the ADP-Glo assay. Statistical significance was determined using a one-way ANOVA followed by Šidák’s’s multiple comparison post-test (FIKK13_4 versus no substrate, p < 0.0001; FIKK13_4_Y10A versus no substrate, p = 0.0760; FIKK13_4_S7A_Y10A versus no substrate, p = 0.9982; FIKK13_4_Y10A versus FIKK13_4, p < 0.0001; FIKK13_4_S7A versus FIKK13_4_Y10A, p < 0.0001). n = 3 biological independent replicates.
