Ligand Binding Properties of Bacterial Hemoglobins and Flavohemoglobins
| Autor: | and Alexander D. Frey, Markus P. Rechsteiner, Pauli Kallio, Susanna Herold, Judith Farrés |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Hemeproteins
Clostridium perfringens Molecular Sequence Data Plasma protein binding Bacillus subtilis Ligands Biochemistry Campylobacter jejuni Hemoglobins chemistry.chemical_compound Bacterial Proteins Dihydropteridine Reductase NADH NADPH Oxidoreductases Amino Acid Sequence Photolysis Autoxidation biology Chemistry Nitric oxide binding Escherichia coli Proteins Salmonella enterica biology.organism_classification Globin fold Kinetics Myoglobin Spectrophotometry Carbon monoxide binding Protein Binding |
| Zdroj: | Biochemistry. 44:4125-4134 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi047389d |
| Popis: | Bacterial hemoglobins and flavohemoglobins share a common globin fold but differ otherwise in structural and functional aspects. The bases of these differences were investigated through kinetic studies on oxygen, carbon monoxide, and nitric oxide binding. The novel bacterial hemoglobins from Clostridium perfringens and Campylobacter jejuni and the flavohemoglobins from Bacillus subtilis and Salmonella enterica serovar Typhi have been analyzed. Examination of the biochemical and ligand binding properties of these proteins shows a clear distinction between the two groups. Flavohemoglobins show a much greater tendency to autoxidation compared to bacterial hemoglobins. The differences in affinity for oxygen, carbon monoxide, and nitric oxide between bacterial hemoglobins and flavohemoglobins are mainly due to differences in the association rate constants. The second-order rate constants for oxygen and carbon monoxide binding to bacterial hemoglobins are severalfold higher than those for flavohemoglobins. A similar trend is observed for NO association with the oxidized iron(III) form of the proteins. No major differences are observed among the values obtained for the dissociation rate constants for the two groups of bacterial proteins studied, and these constants are all rather similar to those for myoglobin. Taken together, our data suggest that differences exist between the mechanisms of ligand binding to bacterial hemoglobins and flavohemoglobins, suggesting different functions in the cell. |
| Databáze: | OpenAIRE |
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