Effects of cross-linking and zero-link polymerization on oxygen transport and redox chemistry of bovine hemoglobin.
Effects of cross-linking and zero-link polymerization on oxygen transport and redox chemistry of bovine hemoglobin.
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交联和零键聚合对牛血红蛋白氧传输和氧化还原化学的影响。
DOI：
10.1016/j.bbapap.2009.04.008
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
A. Alayash
中科院分区：
文献类型：
--
作者：
Yiping Jia;A. Alayash
交联血红蛋白（Hbs）被发现具有增强的氧化反应，这损害了无细胞血红蛋白携带氧气的能力。零连接牛血红蛋白（ZL-HbBv），也称为OxyVita™，是一种通过相邻四聚体表面上的假肽键结合在一起的大聚合物，提供了一种可以评估这些反应的模型。ZL-HbBv的氧亲和力大大增加，而氧结合协同性（n50）以及对pH和氯离子的调节反应减弱。快速混合动力学研究表明，更快的一氧化碳（CO）和一氧化氮（NO）结合ZL-HbBv，符合更容易血红素口袋构象。亚铁ZL-HbBv的自氧化速率比未修饰的HbBv（对照）快3倍，但仅被超氧化物歧化酶和过氧化氢酶的存在轻微抑制。铁ZL-HbBv的过氧化氢（H2 O2）反应速率及其降解与对照相当。从ZL-HbBv到突变体脱辅基肌红蛋白（H64 Y/V68 F）的血红素损失速率也非常接近于对照。两者合计，该蛋白质的变构和氧化还原反应由于血红素对溶剂的可及性而改变，然而，ZL-HbBv聚合物的紧凑四聚体与四聚体的相互作用似乎限制血红素损失，即使在过量H2 O2的存在下也是如此。
Cross-linked hemoglobins (Hbs) were found to have enhanced oxidative reactions which compromise the ability of cell-free Hb to carry oxygen. Zero-link bovine Hb (ZL-HbBv), also known as OxyVita™, a large polymer held together by pseudopeptide bonds on the surface of adjacent tetramers, provides a model in which these reactions can be evaluated. The oxygen affinity of ZL-HbBv was greatly increased, whereas the oxygen binding cooperativity (n50) as well as the regulatory responses to pH and chloride ions was diminished. Rapid mixing kinetic studies revealed faster carbon monoxide (CO) and nitric oxide (NO) binding to ZL-HbBv, consistent with a more accessible heme pocket conformation. The rate of autoxidation of ferrous ZL-HbBv was 3 folds faster than the unmodified HbBv (control) but only slightly suppressed by the presence of superoxide dismutase and catalase enzymes. The peroxide (H2O2) reaction rates of ferric ZL-HbBv and its degradation were comparable to that of the control. The rate of heme loss from ZL-HbBv to a mutant apomyoglobin (H64Y/V68F) was also very close to that of the control. Taken together, allosteric and redox reactions of this protein are altered due to heme accessibility to solvent, however, the compact tetramer to tetramer interaction of the ZL-HbBv polymer appears to restrict heme loss even in the presence of excess H2O2.
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影响因子：
2.9
作者：
E. Nagababu;S. Ramasamy;J. Rifkind;Yiping Jia;A. Alayash
通讯作者：
E. Nagababu;S. Ramasamy;J. Rifkind;Yiping Jia;A. Alayash
影响因子：
2.9
作者：
Eich, RF;Li, TS;Olson, JS
通讯作者：
Olson, JS
影响因子：
2.9
作者：
V. Sharma;T. Traylor;Robert T. Gardiner;H. Mizukami
通讯作者：
V. Sharma;T. Traylor;Robert T. Gardiner;H. Mizukami
DOI：
10.1016/j.bbapap.2008.04.032
发表时间：
2008-10
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
R. Winslow
通讯作者：
R. Winslow
影响因子：
4.1
作者：
Vandegriff, Kim D.;Malavalli, Ashok;Winslow, Robert M.
通讯作者：
Winslow, Robert M.