Examination of the effect of a Histidine tag and pH on the energy landscape of ACBP
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Document Type
Abstract
Publication Date
10-2-2019
Abstract
A polyhistidine-tag is an amino acid motif in proteins that consists of at least six histidine (His) residues, often at the N- or C-terminus of the protein. While a 6 Histidine residue tag has multiple functions, it is often attached to the end of a protein for use in protein purification. It is important to determine if the His-tag has an effect on protein folding and stability. We use ACBP as our model because ACBP is a single-domain protein that is thought to fold in a two-state process. To characterize how the His-tag affects the protein energy landscape, we study the effects of ACBP stability and folding kinetics with and without a His-tag in different buffers with varying pHs of 5.3 and 7. At a pH of 5.3 Histidine is protonated and at 7 Histidine is deprotonated. We observed that there was a significant difference in the kinetics and thermodynamics of the C- Term His tagged ACBP. In a pH of 5.3, the C-Term His tagged ACBP was less stable whereas in a pH of 7 it was more stable. There was no significant difference in the thermodynamics or the kinetics of the N-term ACBP and the wild type ACBP.
Project Mentor
Prof. E. Guinn, PhD
Recommended Citation
Cecil, Karson and Van Dyck, Papa Kobina, "Examination of the effect of a Histidine tag and pH on the energy landscape of ACBP" (2019). Annual Student Research Poster Session. 173.
https://scholarship.depauw.edu/srfposters/173
Funding and Acknowledgements
Funding: Science Research Fellows Program, Faculty Development Program