Tat1-72, is an intrinsically disordered protein at pH 4.1 as previously indicated by NMR chemical shifts and coupling constants, and confirmed by 15N-relaxation parameters. The presence of SDS elicits a conformational change to α-helicity in Tat1-72. In the presence of the non-ionic DDM detergent and zinc, Tat was found to be soluble at pH 4 when bound to TAR RNA; TAR binding also elicits a conformational shift to α-helicity in Tat1-72. The β-sheet content of Tat1-72 is increased in the presence of NaCl. In similar conditions, Tat1-72 aggregates stained with Congo Red displayed a yellow-green birefringence and a red-shift in the Congo Red absorbance that is typical of β-amyloid fibril. The web-based algorithm “WALTZ” identifies the majority of the Tat1-72 hydrophobic core region as amyloidogenic. The helical propensity of Tat1-72 in TFE was determined by two-dimensional NMR spectroscopy.
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/4594 |
| Date | 20 April 2011 |
| Creators | Babiak, Taras |
| Contributors | O'Neil, Joe (Chemistry), Stetefeld, Jorg (Chemistry) Mark, Brian (Microbiology) |
| Source Sets | University of Manitoba Canada |
| Language | en_US |
| Detected Language | English |
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