Characterization and bioactivity of self-assembled anti-angiogenic chondroitin sulfate-ES2-AF nanoparticle conjugate

Xing, Liang; Sun, Feng; Wang, Zhendong; Li, Yan; Yang, Zhifang; Wang, Fengshan; Zhai, Guangxi; Tan, Haining

CS-ES2-AF flowed through the CM5 chip to generate dynamic sensing fitting plots. The affinity kinetic parameters K a (L/(mol × s)) and K d (1/s) of the interaction of CD44 protein with CS-ES2-AF and ES2-AF were 6,846, 6.863×10 -5 and 0, 0, respectively. Here, K a is the binding constant between the sample and CD44, K d is the dissociation constant of the sample and CD44, and KD (K d /K a ) is the equilibrium dissociation constant, which was used to measure the ability of CD44 to interact with the sample; the smaller the KD value, the stronger the affinity of CD44 to the sample. The KD value of ES2-AF and CD44 was 3.011×10 -4 ( Figure 5C ), while the KD value of CS-ES2-AF and CD44 was much smaller, 9.985×10 -9 ( Figure 5B ). This indicated that the binding affinity of the CS-modified glycosylated polypeptide ES2-AF to the CD44 receptor was better than the affinity of the unmodified polypeptide ES2-AF.