Elucidating binding capacities of different sialic acid-carrying polymer substrates with Siglec-9 by Optical Tweezers - Studies of the importance of mucin glycosylation for cancer progression

Abstract

The experimental data regarding interaction studies and energy landscape presented in this master thesis were obtained using a dual-beam Optical Tweezers. The main objective of this study was to investigate the binding of Siglec-9 to MUC1-ST and to PAA-ST to determine the differences in affinity. Results obtained indicated that MUC1-ST interacts with Siglec-9 with a rupture force of 7.2-22.2 pN for loading rates ranging from 53-174 pN. Estimates of parameters characteristic for the energy landscape resulted in k_off between 0.92-2.2 s-1, and x_β from 0.35-1.40 nm. For PAA-ST interacting with Siglec-9 the rupture force was 10.2-34.2 pN for a loading rate ranging from 50-189 pN, k_off between 1.0-1.9 s-1, and x_β from 0.33-1.30 nm. MUC1-ST was found to interact with Siglec-9 at a higher frequency compared to PAA-ST.