BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Polymer switch shows B-protein G size-selective blockade of streptavidin binding pocket B-BSA a:: Figure 1 sheldig of binny ated proten bndng D BIN118K-PDENmc bindng of biotinylated BSA ( B-BSA b the E51KN118K-PDEAAm-12 E51NNl18K-PDEAAm-12 8k conjugate (open circles ef cient over the who terperature range estimated, while the binding of the lage proten B-lgg to the rature range Uhor he bindng conditons used (see Meto), the E51KN118K- PDEAm- 12. 8k corium has an LaST df C fopen triangles Also the basis for triggered release switches o Expose biotin-loaded conjugates to successive cycles of T TLcsT through T> TLCST 4 cycles kick out all bound biotin All bound biotin released by 4 temperature cycles 37ic E116C.pP 图E16c ST 24i c 374374374374 4i c Figure 8. Cumulative release of bound bi duplicate experiments. Magnetic beac mobilized with 5.4 x 10-10 mol of E116C assay. Sodium phosphate buffer, PH 7.4 (Ding et al., 1999) Mechanisms for controlling access by large or small ligands o Small ligands have access to binding pocket next to immobilized chain blocked when chain is collapsed but can access the pocket when the chain is hydrated Conversely, if biotin binds in the pocket, collapse of the chain can eject the bound small ligand Lecture 13-Hybrid macromolecules 3 of 13BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 size-selective blockade of streptavidin binding Polymer switch shows pocket: ƒ Also the basis for triggered release switches o Expose biotin-loaded conjugates to successive cycles of T < TLCST through T > TLCST ƒ 4 cycles ‘kick out’ all bound biotin All bound biotin released by 4 temperature cycles: (Ding et al., 1999) TLCST 37¡C 4¡C = 24¡C ƒ Mechanisms for controlling access by large or small ligands o Small ligands have access to binding pocket next to immobilized chain blocked when chain is collapsed, but can access the pocket when the chain is hydrated ƒ Conversely, if biotin binds in the pocket, collapse of the chain can eject the bound small ligand Lecture 13 – Hybrid macromolecules 3 of 13