POLY 251 |
| Hinge motion binding proteins, like the periplasmic binding proteins of bacteria, undergo substantial conformational changes upon binding to their ligands. Therefore these proteins behave as stimuli-responsive molecular machines, and can be utilized for the development of stimuli-responsive hydrogels. The protein calmodulin (CaM), was selected as a model hinge motion binding protein, and was integrated along with a low-affinity ligand (phenothiazine) in the bulk of a porous hydrogel network. CaM binds to phenothiazine creating chemical crosslinks and causing the hydrogel to adopt a constricted (shrunken) configuration. Upon the addition of a high-affinity ligand, like chlorpromazine, the protein prefers to release phenothiazine breaking the chemical crosslinks, and bind to the free chlorpromazine. As a result the hydrogel undergoes a phase transition adopting a higher volume (swollen) configuration. We have taken advantage of this mechanism of actuation to incorporate it in high throughput screening systems, as well as in responsive drug delivery devices and smart microlenses. |
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Polymers in Biosensors and Biochips
8:30 AM-11:50 AM, Monday, 11 September 2006 San Francisco Marriott -- Salon 12/13, Oral
Division of Polymer Chemistry |