Conformational changes of human neuronal tau during thermal and guanidine-hcl denatura tion

Title:Conformational changes of human neuronal tau during thermal and guanidine-hcl denatura tion

Volume: 7 Issue: 2

Author(s): Jian-Ying Luo, Yang Liu, Qian Bua and Rong-Qiao Be*

Affiliation:

• Lab of Visual If/formation Processing, Institute of Biophysics, The Chinese Academy of Sciences, Beijing I 00I01, China

Abstract: Unfolding of human neuronal tau was studied during incubation with guanidine hydrochloride (GuBCI) and under thermal denaturation conditions. The intensity of the intrinsic fluorescence at 305 nm increased markedly in GuBCI solutions. Fluorescence quenching by potassium iodide showed that Tyr residues approached to the interior of the molecule during GuBCI denaturation. The difference ultraviolet absorbance at 215 nm showed a marked increase above 45°C. Light scattering of tau solution · intensity decreased when temperature increased. Kinetics of the increase in the absorbance was a biphasic procedure. The first order rate of the fast phase was 1.84 x 10-1s-1 and that of the slow phase was 2.68 x 10-2s-1• The difference absorbance of tau was reversible. Kinetics of a decrease in the difference absorbance was a fast procedure during tau refolding. The first order rate of the fast phase was much greater than that of the unfolding procedure. This suggests that tau is not completely at a random conformation at room temperature.

Cite this article as:

Luo Jian-Ying, Liu Yang, Bua Qian and Be Rong-Qiao*, Conformational changes of human neuronal tau during thermal and guanidine-hcl denatura tion, Protein & Peptide Letters 2000; 7 (2) . https://dx.doi.org/10.2174/092986650702221206115838