"Module" substitution in hemoglobin subunits. Preparation and characterization of a "chimera beta alpha-subunit".
"Module" substitution in hemoglobin subunits. Preparation and characterization of a "chimera beta alpha-subunit".
复制标题
血红蛋白亚基中的“模块”替换。
DOI：
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发表时间：
1994
影响因子：
4.8
通讯作者：
I. Morishima
中科院分区：
文献类型：
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作者：
K. Wakasugi;K. Ishimori;K. Imai;Y. Wada;I. Morishima
在血红蛋白的α亚基和β亚基的基因中，Go显示模块F1、F2 + F3和F4分别对应于外显子1、2和3（Go，M.（1981）Nature 291，90）。功能与其外显子模式的相关性分析显示，与限定功能相关的残基集中在编码“模块”的特定外显子中（Eaton，W.A.（1980）Nature 284，183）。为了研究“模块结构”的功能和结构意义，我们设计了“嵌合体”亚基，其中通过使用诱变将β亚基的模块F4替换为α亚基的模块F4。分离的“嵌合体β α-亚基”的NMR和共振拉曼光谱揭示了它具有β-亚基样血红素环境结构。然而，嵌合体和天然亚基混合物的凝胶色谱和核磁共振光谱清楚地表明，嵌合体β α亚基与β亚基特异性结合以形成异四聚体，而不是与α亚基结合。这些结果使我们得出结论，模块F4的主要作用是亚基协会，并建议模块的结构和功能单位，具有优势，在生产稳定的功能蛋白质。
In the genes of alpha- and beta-subunits of hemoglobin, Go showed that modules F1, F2 + F3, and F4 correspond to exons 1, 2, and 3, respectively (Go, M. (1981) Nature 291, 90). The analysis of the correlation of function with its exon pattern showed that the residues associated with the defined function are concentrated in the specific exons encoding the "module" (Eaton, W.A. (1980) Nature 284, 183). To investigate the functional and structural significance of the "modular structure," we engineered a "chimera" subunit, in which module F4 of the beta-subunit was replaced by that of the alpha-subunit by use of mutagenesis. The NMR and resonance Raman spectra of the isolated "chimera beta alpha-subunit" have revealed that it has a beta-subunit-like heme environmental structure. However, the gel chromatography and NMR spectra of mixtures of the chimera and native subunits clearly showed that the chimera beta alpha-subunit binds specifically to the beta-subunit to form a heterotetramer, not to the alpha-subunit. These results led us to conclude that the predominant role of the module F4 is the subunit association and suggest that the modules are structural and functional units that have advantages in producing stable functional proteins.