Design and Synthesis of a Transition Metal Responsive Semisynthetic Myoglobin-Bearing Iminodiacetic Acid Moiety
Design and Synthesis of a Transition Metal Responsive Semisynthetic Myoglobin-Bearing Iminodiacetic Acid Moiety
复制标题
过渡金属响应半合成肌红蛋白承载亚氨基二乙酸部分的设计与合成
DOI：
10.1021/ic961474v
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发表时间：
1998
影响因子：
4.6
通讯作者：
S. Shinkai
中科院分区：
文献类型：
--
作者：
I. Hamachi;T. Matsugi;Kengo Wakigawa;S. Shinkai
附加亚氨基二乙酸的肌红蛋白（IDAn-Mb，n = 1, 2）是通过用脱辅基肌红蛋白常规重构化学修饰的血红素来合成的。通过金属离子滴定、pH滴定、圆二色性(CD)和1H NMR光谱以及抗坏血酸还原研究了所得IDAn-Mb的金属响应性质。 IDAn-Mb 定量结合各种过渡金属阳离子（Co2+、Ni2+、Zn2+、Cd2+ 和 Cu2+），但不结合 Mg2+。 IDA2-Mb 的 Co2+、Ni2+、Zn2+ 和 Cd2+ 的结合化学计量为 1:1，Cu2+ 的结合化学计量为 1:2，而 IDA1-Mb 与所有过渡金属（Co2+、Ni2+、Zn2+、Cd2+ 和 Cu2+）的化学计量为 1:1。在过渡金属结合时，可以清楚地观察到与血红素铁 (III) 配位的 H2O 的酸性 pKa 变化，表明血红素缝隙的微环境发生变化。 IDAn-Mb 的 CD 和 1H NMR 谱证实了这一点。过渡金属诱导的 IDAn-Mb 结构变化反映在其氧化还原行为上，即...
Iminodiacetic acid appended myoglobins (IDAn-Mb, n = 1, 2) were synthesized by conventional reconstitution of chemically modified hemes with apomyoglobin. The metal responsive property of the obtained IDAn-Mb was studied by metal ion titration, pH titration, circular dichroism (CD) and 1H NMR spectroscopies, and reduction with ascorbate. IDAn-Mb quantitatively bound various transition metal cations (Co2+, Ni2+, Zn2+, Cd2+, and Cu2+) but not Mg2+. The binding stoichiometry of IDA2-Mb was 1:1 for Co2+, Ni2+, Zn2+, and Cd2+ and 1:2 for Cu2+, whereas the stoichiometry of 1:1 was shown for IDA1-Mb to all transition metals (Co2+, Ni2+, Zn2+, Cd2+, and Cu2+). The acidic pKa shift of the H2O coordinated to the heme iron(III) was clearly observed upon the binding of transition metals, suggesting the microenvironmental change of the heme crevice. This was supported by the CD and 1H NMR spectra of IDAn-Mb. The transition metal induced structural changes of IDAn-Mb were reflected in their redox behavior, i.e., the re...