Determination of Phosphorylation and Deprotonation Induced Higher Order Structural Transitions in αs‑Caseins

Ettah, Ilokugbe and Ashton, Lorna (2019) Determination of Phosphorylation and Deprotonation Induced Higher Order Structural Transitions in αs‑Caseins. Analytical Chemistry, 91 (21). pp. 13940-13946. ISSN 0003-2700

[img]
Text (Ashton_Casein_final manuscript)
Ashton_Casein_final_manuscript.pdf - Accepted Version
Restricted to Repository staff only until 16 October 2020.
Available under License Creative Commons Attribution-NonCommercial.

Download (1MB)

Abstract

One extremely sensitive and highly successful application of Raman spectroscopy is the structural characterization of proteins. Understanding higher order structure and its effect on protein stability is essential not only for biopharmaceutical and food manufacturing but also for the understanding of diseases that result from the misfolding of proteins including diabetes type II, Alzheimer's, and Parkinson's disease. Due to the large amount of structural information available in Raman spectra, even small alterations in protein conformations including increased exposure of binding regions or changes in geometry of secondary structural elements can be identified. In this study, we demonstrate the unique sensitivity of Raman spectroscopy to subtle structural transitions in an intrinsically open, flexible protein, α s-casein, in response to phosphorylation and deprotonation. Through the application of 2D correlation analysis two separate transition phases have been identified from pH 6-9 and pH 10-12 for both phosphorylated and dephosphorylated α s-casein. However, the actual structural changes observed in each pH range differed considerably between the phosphorylated and dephosphorylated α s-casein. Furthermore, the presence of the phosphorylated serine residues is demonstrated to have a shielding effect during deprotonation of the protein.

Item Type:
Journal Article
Journal or Publication Title:
Analytical Chemistry
Additional Information:
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/full/10.1021/acs.analchem.9b03457
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1600/1602
Subjects:
ID Code:
138383
Deposited By:
Deposited On:
30 Oct 2019 08:55
Refereed?:
Yes
Published?:
Published
Last Modified:
30 Sep 2020 09:23