Engineering oxidative stability in human hemoglobin based on the Hb providence (βK82D) mutation and genetic cross-linking
| Autor: | Michael Brad Strader, Rachel E. Bangle, Eileen W. Singleton, Andres S. Benitez Cardenas, Premila P. Samuel, Abdu I. Alayash, Alvin L. Crumbliss, Cornelius L. Varnado, John S. Olson, Claire J. Parker Siburt, Jayashree Soman |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Mutant Mutation Missense medicine.disease_cause Protein Engineering Biochemistry 03 medical and health sciences chemistry.chemical_compound Hemoglobins Tetramer medicine Humans Molecular Biology Heme Mutation 030102 biochemistry & molecular biology Autoxidation Cell Biology Hydrogen Peroxide 030104 developmental biology Cross-Linking Reagents chemistry Hemoglobin Dimerization Oxidation-Reduction Hemin Cysteine |
| Zdroj: | The Biochemical journal. 474(24) |
| ISSN: | 1470-8728 |
| Popis: | Previous work suggested that hemoglobin (Hb) tetramer formation slows autoxidation and hemin loss and that the naturally occurring mutant, Hb Providence (HbProv; βK82D), is much more resistant to degradation by H2O2. We have examined systematically the effects of genetic cross-linking of Hb tetramers with and without the HbProv mutation on autoxidation, hemin loss, and reactions with H2O2, using native HbA and various wild-type recombinant Hbs as controls. Genetically cross-linked Hb Presbyterian (βN108K) was also examined as an example of a low oxygen affinity tetramer. Our conclusions are: (a) at low concentrations, all the cross-linked tetramers show smaller rates of autoxidation and hemin loss than HbA, which can dissociate into much less stable dimers and (b) the HbProv βK82D mutation confers more resistance to degradation by H2O2, by markedly inhibiting oxidation of the β93 cysteine side chain, particularly in cross-linked tetramers and even in the presence of the destabilizing Hb Presbyterian mutation. These results show that cross-linking and the βK82D mutation do enhance the resistance of Hb to oxidative degradation, a critical element in the design of a safe and effective oxygen therapeutic. |
| Databáze: | OpenAIRE |
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