Abstract
We previously reported that poly(N-isopropylacrylamide) grafted with Peptide 1 (-GLRRASLG) and poly(ethylene glycol) changed its physical properties in response to an intracellular protein phosphorylation signal, protein kinase A (PKA) (Katayama, Y. et al. (2001) Macromolecules 34, 905). In this study, we investigated the effect of changing peptide structure on the lower critical solution temperature (LCST) of peptide-polymer conjugates, before and after phosphorylation with PKA. For Peptide 2 (Ac-LRRASL-), which has a formal net charge of +2 at physiological pH, the LCST of the conjugate decreased on phosphorylation. In contrast, the LCSTs of the conjugates with Peptide 3 (-ALRRASLE) and Peptide 4 (Ac-DWDALRRASL-), which have neutral net charges, were greatly increased. This suggests that the LCST of the polymer was mainly governed by two factors: the change in hydration around the polymer chain and the interpeptide electrostatic repulsion, resulting from phosphorylation. These polymers have potential for use as drug capsules that respond to cellular conditions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
