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https://hdl.handle.net/11147/5062
Title: | Conformational and Aggregation Properties of a Pegylated Alanine-Rich Polypeptide | Authors: | Top, Ayben Roberts, Christopher J. Kiick, Kristi L. |
Keywords: | Acidic conditions Sheet formation Elevated temperature Polypeptides Amino acids |
Publisher: | American Chemical Society | Source: | Top, A., Roberts, C.J., and Kiick, K.L. (2011). Conformational and aggregation properties of a pegylated alanine-rich polypeptide. Biomacromolecules, 12(6), 2184-2192. doi:10.1021/bm200272w | Abstract: | The conformational and aggregation behavior of PEG conjugates of an alanine-rich polypeptide (PEG-c17H6) were investigated and compared to that of the polypeptide equipped with a deca-histidine tag (17H6). These polypeptides serve as simple and stimuli-responsive models for the aggregation behavior of helix-rich proteins, as our previous studies have shown that the helical 17H6 self-associates at acidic pH and converts to β-sheet structures at elevated temperature under acidic conditions. In the work here, we show that PEG-c17H6 also adopts a helical structure at ambient/subambient temperatures, at both neutral and acidic pH. The thermal denaturation behavior of 17H6 and PEG-c17H6 is similar at neutral pH, where the alanine-rich domain has no self-association tendency. At acidic pH and elevated temperature, however, PEGylation slows β-sheet formation of c17H6, and reduces the apparent cooperativity of thermally induced unfolding. Transmission electron microscopy of PEG-c17H6 conjugates incubated at elevated temperatures showed fibrils with widths of ∼20-30 nm, wider than those observed for fibrils of 17H6. These results suggest that PEGylation reduces β-sheet aggregation in these polypeptides by interfering, only after unfolding of the native helical structure, with interprotein conformational changes needed to form β-sheet aggregates. | URI: | https://doi.org/10.1021/bm200272w http://hdl.handle.net/11147/5062 |
ISSN: | 1526-4602 1525-7797 |
Appears in Collections: | Chemical Engineering / Kimya Mühendisliği PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection |
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