A role of heme side-chains of human hemoglobin in its function revealed by circular dichroism and resonance Raman spectroscopy
| Autor: | Masako Nagai, Teizo Kitagawa, Naoki Mizusawa, Shigenori Nagatomo |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Circular dichroism Resonance Raman spectroscopy Biophysics Review 010402 general chemistry 01 natural sciences Dissociation (chemistry) 0104 chemical sciences 03 medical and health sciences Crystallography chemistry.chemical_compound symbols.namesake 030104 developmental biology chemistry Structural Biology symbols Side chain Hemoglobin Raman spectroscopy Molecular Biology Heme Homotetramer |
| Zdroj: | Biophysical Reviews. 10:271-284 |
| ISSN: | 1867-2469 1867-2450 |
| DOI: | 10.1007/s12551-017-0364-5 |
| Popis: | Structural changes of heme side-chains of human adult hemoglobin (Hb A) upon ligand (O2 or CO) dissociation have been studied by circular dichroism (CD) and resonance Raman (RR) spectroscopies. We point out the occurrence of appreciable deformation of heme side-chains like vinyl and propionate groups prior to the out-of-plane displacement of heme iron. Referring to the recent fine resolved crystal structure of Hb A, the deformations of heme side-chains take place only in the β subunits. However, these changes are not observed in the isolated β chain (β4 homotetramer) and, therefore, are associated with the α–β inter-subunit interactions. For the communications between α and β subunits in Hb A regarding signals of ligand dissociation, possible routes are proposed on the basis of the time-resolved absorption, CD, MCD (magnetic CD), and RR spectroscopies. Our finding of the movements of heme side-chains would serve as one of the clues to solve the cooperative O2 binding mechanism of Hb A. |
| Databáze: | OpenAIRE |
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