Biomedical Research Center, KIST, Republic of Korea.
Biochem Biophys Res Commun. 2010 Apr 9;394(3):515-21. doi: 10.1016/j.bbrc.2010.03.002. Epub 2010 Mar 4.
This study reports the crystal structures of Bcl-xl wild type and three Bcl-xl mutants (Y101A, F105A, and R139A) with amino acid substitutions in the hydrophobic groove of the Bcl-xl BH3 domain. An additional 12 ordered residues were observed in a highly flexible loop between the alpha1 and alpha2 helices, and were recognized as an important deamidation site for the regulation of apoptosis. The autophagy-effector protein, Beclin 1, contains a novel BH3 domain (residues 101-125), which binds to the surface cleft of Bcl-xl, as confirmed by nuclear magnetic resonance (NMR) spectroscopy and analytical gel-filtration results. Gossypol, a potent inhibitor of Bcl-xl, had a K(d) value of 0.9 microM. In addition, the structural and biochemical analysis of five Bcl-xl substitution mutants will provide structural insights into the design and development of anti-cancer drugs.
本研究报告了 Bcl-xl 野生型和三个 Bcl-xl 突变体（Y101A、F105A 和 R139A）的晶体结构，这些突变体在 Bcl-xl BH3 结构域的疏水性凹槽中发生了氨基酸取代。在α1 和α2 螺旋之间的高度灵活的环中观察到另外 12 个有序残基，被认为是调节细胞凋亡的重要脱酰胺化位点。自噬效应蛋白 Beclin 1 含有一个新的 BH3 结构域（残基 101-125），通过核磁共振（NMR）光谱和分析凝胶过滤结果证实，它与 Bcl-xl 的表面裂缝结合。棉酚是 Bcl-xl 的有效抑制剂，其 K(d) 值为 0.9 μM。此外，对五个 Bcl-xl 取代突变体的结构和生化分析将为抗癌药物的设计和开发提供结构见解。
