Novel Redox Active Tyrosine Mutations Enhance the Regeneration of Functional Oxyhemoglobin from Methemoglobin: Implications for Design of Blood Substitutes.
Novel Redox Active Tyrosine Mutations Enhance the Regeneration of Functional Oxyhemoglobin from Methemoglobin: Implications for Design of Blood Substitutes.
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新型氧化还原活性酪氨酸突变增强高铁血红蛋白功能性氧合血红蛋白的再生：对血液替代品设计的影响。
DOI：
10.1007/978-3-319-91287-5_35
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发表时间：
2018
影响因子：
--
通讯作者：
Silkstone GGA
中科院分区：
文献类型：
--
作者：
Silkstone GGA
血红素介导的氧化毒性与基于血红蛋白的氧载体（HBOC）中的不良副作用有关，其由活性铁基（FeIV）铁和基于球蛋白的自由基物质引发。我们最近发现，在重组血红蛋白的β亚基（β F41 Y）中添加氧化还原活性酪氨酸残基，能够通过促进血浆抗氧化剂（如抗坏血酸盐）还原FeIV铁来降低脂质过氧化作用。为了进一步探索这种功能，我们创建了一套酪氨酸突变体，其被设计为在蛋白质表面处可接近还原剂，但足够接近血红素辅因子以使电子能够有效地转移到FeIV。选择的残基是：β F41 Y; β K66 Y; β F71 Y; β T84 Y; β F85 Y;和β L96 Y。与β F41 Y一样，所有突变体均显著提高了抗坏血酸盐还原铁（FeIV）至铁（FeIII）的速率。然而，令人惊讶的是，这些突变的一个子集（β T84 Y和β F85 Y）也增强了三价铁（FeIII）进一步还原为亚铁（FeII）血红素，再生功能性氧合血红蛋白。在β T84 Y中观察到最大的增加，在100 μM抗坏血酸存在下，在60 min内由铁血红蛋白形成的氧合血红蛋白的百分比从β F41 Y中的10%增加到β T84 Y中的50%以上。这种增加伴随着抗坏血酸消耗率的增加。我们的结论是，插入新的氧化还原活性酪氨酸残基可能是一个有用的组成部分，任何重组HBOC设计的功能活性较长，没有氧化副作用。
Heme mediated oxidative toxicity has been linked to adverse side effects in Hemoglobin Based Oxygen Carriers (HBOC), initiated by reactive ferryl (FeIV) iron and globin based free radical species. We recently showed that the addition of a redox active tyrosine residue in the beta subunit (βF41Y) of recombinant hemoglobin had the capability to decrease lipid peroxidation by facilitating the reduction of FeIViron by plasma antioxidants such as ascorbate. In order to explore this functionality further we created a suite of tyrosine mutants designed to be accessible for both reductant access at the protein surface, yet close enough to the heme cofactor to enable efficient electron transfer to the FeIV. The residues chosen were: βF41Y; βK66Y; βF71Y; βT84Y; βF85Y; and βL96Y. As with βF41Y, all mutants significantly enhanced the rate of ferryl (FeIV) to ferric (FeIII) reduction by ascorbate. However, surprisingly a subset of these mutations (βT84Y, and βF85Y) also enhanced the further reduction of ferric (FeIII) to ferrous (FeII) heme, regenerating functional oxyhemoglobin. The largest increase was seen in βT84Y with the percentage of oxyhemoglobin formed from ferric hemoglobin in the presence of 100 μM ascorbate over a time period of 60 min increasing from 10% in βF41Y to over 50% in βT84Y. This increase was accompanied by an increased rate of ascorbate consumption. We conclude that the insertion of novel redox active tyrosine residues may be a useful component of any recombinant HBOC designed for longer functional activity without oxidative side effects.
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影响因子：
4.1
作者：
Vandegriff, Kim D.;Malavalli, Ashok;Winslow, Robert M.
通讯作者：
Winslow, Robert M.
人类血红蛋白的 βLys66Tyr 变体作为血液替代品的组成部分。
影响因子：
--
作者：
R. Silkstone;G. Silkstone;J. A. Bååth;B. Rajagopal;P. Nicholls;B. Reeder;L. Ronda;L. Bulow;C. Cooper
通讯作者：
C. Cooper
DOI：
10.1042/bcj20160243
发表时间：
2016-10-01
期刊：
The Biochemical journal
影响因子：
--
作者：
Silkstone GG;Silkstone RS;Wilson MT;Simons M;Bülow L;Kallberg K;Ratanasopa K;Ronda L;Mozzarelli A;Reeder BJ;Cooper CE
通讯作者：
Cooper CE
DOI：
10.1016/j.bbapap.2008.03.019
发表时间：
2008-10-01
影响因子：
3.2
作者：
Cooper, Chris E.;Silaghi-Dumitrescu, Radu;Buehler, Paul W.
通讯作者：
Buehler, Paul W.