Subject Number :S-20-MS-1078
Support Type : (select) Common use (including technical support necessary for the training),
Technical support (except the training), Technical surrogate,
Collaborative research, Technical consultation
Proposal Title (English) : Interaction of protein with polymers
Username (English) :Robin Rajan1, Kazuaki Matsumura1
Affiliation (English) :1) School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan

1. Summary
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2. Experimental
I used isothermal titration calorimetry (ITC) to quantitatively study the interaction of proteins with my polymers (lysozyme). I used various types of polymers, including different functional groups and different polymer architectures and compared the difference in this mode of interaction with lysozyme using isothermal titration calorimeter (MicroCal iTC200) with the help of Haruyo Nagao.

3. Results and Discussion
We had previosuly established in our research that poly-SPB, which is a zwitterionic polymers (especially hydrophic derivatives, poly-SPB with BuMA) show great ability in protecting proteins under severe stess. For further studies, I need to find out the mechanism of protection and for this, establishing the kind of interaction existing between these polymers and proteins is very important. To this end, I titrated tested poly-SPB with and without hydrophobicity against a fixed concentration of lysozyme using ITC to quantitatively study the interaction. Preliminary studies using ITC gave an indication that hydrophobic polymers show greater affinity for proteins (Fig. 1), which is also consistent with our other results which suggested greater protection, owing to stronger interaction. In future studies, I need to optimize the conditions further and test several polymers with different concentrations, which can conclusively establish the interactions existing between proteins and these polymers.

Figure 1. ITC binding curves for polymers (1mM) and lysozyme (0.025mM).

4. Others
(Describe references, explanation of the technical terms and acknowledgements if necessary. If you have no items mentioned, describe “N/A“.)
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5. Publication/Presentation
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6. Patent
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