Author(s)

Xin Zhao, Yong Shi, Li Chen, Fenlin Sheng, Haiyan Zhou

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The wheat roots membrane separates the cell from the environment around it and encloses the cell contents. The pro-tein secondary structure and thermal stability of the plasma membrane of wheat root have been characterized in D₂O buffer from 20°C to 90°C by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Quantitative analysis of the amide I band (1700 - 1600 cm^–1) showed that the plasma membrane proteins contains 41% α-helix, 16% β-sheet, 18% turn, and 25% disorder structures at 20°C. At elevated temperatures from 25°C up to 90°C, the α-helix and the β-sheet structure unfold into turns and the disorder structure, with a major conformational transition occurring at 50°C. There is a rapid decline in H⁺-ATPase activity of plasma membrane from 35°C to 55°C and it remain very low level H⁺-ATPase activity of PM from 55°C to 90°C. Therefore the protein conformational transition was one of reasons of loses H⁺-ATPase activity of plasma membrane.

Plasma Membrane, Heat Stress, Protein Second Structure, ATR-FTIR

Zhao, X. , Shi, Y. , Chen, L. , Sheng, F. and Zhou, H. (2011) Secondary Structure Changes and Thermal Stability of Plasma Membrane Proteins of Wheat Roots in Heat Stress. American Journal of Plant Sciences, 2, 816-822. doi: 10.4236/ajps.2011.26096.