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Quantitative evaluation for the role of β146 His and β143 His residues in the Bohr effect of human hemoglobin in the presence of 0.1 M chloride ion
http://hdl.handle.net/2297/46942
http://hdl.handle.net/2297/469425b15cea4-ea1b-479a-b2c5-4fa44b7d4f06
| 名前 / ファイル | ライセンス | アクション |
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ME-PR-MAWATARI-K-11479.pdf (993.4 kB)
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| Item type | 学術雑誌論文 / Journal Article(1) | |||||
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| 公開日 | 2017-10-03 | |||||
| タイトル | ||||||
| タイトル | Quantitative evaluation for the role of β146 His and β143 His residues in the Bohr effect of human hemoglobin in the presence of 0.1 M chloride ion | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| 著者 |
Matsukawa, Shigeru
× Matsukawa, Shigeru× Itatani, Yoshitaka× Mawatari, Kazuhiro× Shimokawa, Yakichi× Yoneyama, Yoshimasa |
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| 書誌情報 |
Journal of Biological Chemistry 巻 259, 号 18, p. 11479-11486, 発行日 1984-01-01 |
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| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0021-9258 | |||||
| NCID | ||||||
| 収録物識別子タイプ | NCID | |||||
| 収録物識別子 | AA00251083 | |||||
| DOI | ||||||
| 関連タイプ | isIdenticalTo | |||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | https://doi.org/10.1016/S0021-9258(18)90886-0 | |||||
| PMID | ||||||
| 関連タイプ | isIdenticalTo | |||||
| 識別子タイプ | PMID | |||||
| 関連識別子 | 6470009 | |||||
| 出版者 | ||||||
| 出版者 | American Society for Biochemistry and Molecular Biology Inc. | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Two different methods were used to determine the number of Bohr protons released upon oxygenation of human hemoglobin (Hb A) and Hb A lacking β146 His (des-His Hb A) at the pH ranging from pH 5.0 to 9.0 in the presence of 0.1 M Cl- at 25 °C. One is the direct differential titration method, the other is based on the measurement of oxygen affinity as a function of pH. The results obtained for Hb A or des-His Hb A with two methods were completely mutually consistent. The number of Bohr protons released from des-His Hb A upon oxygenation at pH 7.5 was about 44% less than that from Hb A, while at pH 5.5 the number of Bohr protons taken up by des-His Hb A was 20% greater than that by Hb A. The differences in the number of Bohr protons between Hb A and des-His Hb A could not be simply ascribed to the lack of β146 His from Hb A. The pK(a) values, which were determined by the deuterium exchange method using 1H NMR, were 8.0 for β146 His of deoxy-Hb A and 6.5 for that of CO Hb A, while those of β143 His were 5.2 for deoxy-Hb A and 6.0 for CO Hb A. From these pK(a) values, in addition to those of α1 Val proposed for the modified CO and deoxy-Hb A with carbamylated β chains by Van Beek and de Bruin, it became evident that almost all (about 92%) of the alkaline Bohr protons released upon oxygenation of Hb A in the presence of 0.1 M Cl- could be acountd for by the protons from these 2 residues, although the involvement of other histidine residues could not be denied. About half the acid Bohr protons from Hb A, which corresponds to the higher pH part (above pH 5.0) of the acid Bohr effect, could be explained by the involvement of β143 His residue. The residual acid Bohr effect in the more acidic pH region was presumably contributed by an amino acid residue with pK(a) values of 4.05 and 5.95 for the deoxy- and CO Hb A, respectively, although the amino acid residue was unspecified. In des-His Hb A, however, the acid and alkaline Bohr effects could not be satisfactorily explained if the pK(a) values of β143 His and α1 Val remained unchanged in comparison with those of Hb A and moreover the involvement of other residues in the Bohr effect was not taken into account. These results indicate that removal of β-carboxyl terminal histidine may cause considerably large perturbations to the tertiary structure of the subunit and/or to the deoxy-quaternary structure of des-His Hb A, so that its acid and alkaline Bohr effects may be altered more extensively than would be expected by deletion of only 1 residue. | |||||
| 著者版フラグ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
