Figure 2.

Peptides derived from KIF13B inhibit vascular endothelial growth factor (VEGF)–induced angiogenesis. A: Schematic of the domains of KIF13B and truncated domains used in the study. Domains of unknown function (DUF) 2C1 [1202-1240 amino acids (aa)], C2 (1221-1260 aa), C3 (1241-1281 aa), C4 (1226-1251 aa), C5 (1238-1260 aa), C6 (1238-1254 aa), C7 (1261-1281 aa), C8 (1251-1268 aa), and C9 (1235-1252 aa) were expressed as recombinant proteins in bacteria and tested for binding to vascular endothelial growth factor receptor 2 (VEGFR2) by pull-down assay. O, X, and triangle indicate binding, no binding, and partial or unstable binding, respectively. Binding region is indicated as pink shadow. B and C:In vitro two-dimensional capillary network formation of human primary umbilical vein endothelial cells treated with either control virus or virus encoding truncated mutants of FLAG-KIF13B in Matrigel supplemented with VEGF. C_T (1528-1826 aa) was used as a negative control because it did not bind to VEGFR2.¹⁶D and E: Hematoxylin and eosin staining of Matrigel plug was supplemented with 4.4 nmol/L VEGF, 50 ng/mL of basic fibroblast growth factor, 60 U of heparin, and 0.8 × 10⁸ IFU lentivirus (vector control, DUF2, or DUF2C5, or C_T) and injected s.c. in C57BL6 mice. Data are expressed as means ± SEM (C and E). n = 15, 9, 6, 6, 6, 6, 6, and 3 for the groups, respectively (C); n = 4, 4, 5, and 5 for vector control, DUF2, DUF2C5, and C_T, respectively (E). ^∗P < 0.05 (one-way analysis of variance). Scale bars = 100 μm (B and D). IFU, infectious unit; KAI, kinesin-derived angiogenesis inhibitor.