层理鞭枝藻藻红蓝蛋白裂合异构酶色氨酸环境的光谱探测

Spectral analyses on tryptophan environment in phycoerythrocyanin isomerase/lyase of Mastigocladus laminosus

应用N-溴化琥珀酰亚胺(N-bromosuccinimide)研究了层理鞭枝藻藻红蓝蛋白裂合异构酶(PecE、PecF)色氨酸的化学修饰,用紫外吸收光谱、圆二色光谱和荧光光谱探测了色氨酸化学修饰过程中蛋白质结构微观环境,发现PecE和PecF的色氨酸都处在疏水区域或带负电荷区域,PecE的色氨酸残基更靠近分子表面.由于色氨酸是藻红蓝蛋白裂合异构酶的必需氨基酸,这些分析加深了解了色氨酸在藻红蓝蛋白裂合异构酶催化过程中的作用.

Tryptophans in phycoerythrocyanin isomerase/lyase （PecE, PecF） were modified chemically. The structural changes of the enzyme and involved tryptophans were analysed with UV absorption, circular dichroism and fluorescence spectra. It is indicated that the tryptophan in PecE is near to the surface of PecE, and the tryptophans of PecE and PecF are situated at hydrophobic or negative charged motif. The results could help to know the enzymatic mechanism of PecF and PecF.