CD STUDY OF UREA INDUCED UNFOLDING OF GAL REPRESSOR OF E COLI

E. Coli（GalR）调节转录， 半乳糖操纵子 它是一种二聚体蛋白， 诱导物，D-半乳糖，每个亚基。 该蛋白质是从一种 细菌表达系统，并且通常在包涵体中发现。 在研究包涵体中GalR的复性时， 对它的展开特性产生了兴趣。 内在色氨酸 荧光基本上被猝灭，并且其发射峰是红色的 当蛋白质在尿素中展开时发生了变化。 D-半乳糖的结合 对尿素诱导的变性产生显著的稳定性。 CD测量将提供独立的 GalR在尿素中展开的测量，其可以与我们的 荧光数据。

The gal repressor of E. Coli (GalR) regulates transcription from the gal operon. It is a dimeric protein that binds one molecule of inducer, D-galactose, per subunit. The protein is obtained from a bacterial expression system and is often found in inclusion bodies. While investigating renaturation of GalR from inclusion bodies, we became interested in its unfolding properties. Intrinsic tryptophan fluorescence is substantially quenched and its emission peak is red shifted when the protein unfolds in urea. Binding of D-galactose causes significant stabilization against urea induced denaturation. CD measurements will provide an independent measure of GalR unfolding in urea which can be correlated with our fluorescence data.