Báo cáo khoa học: The oxidation process of Antarctic fish hemoglobins

The Oxidation Process of Antarctic Fish Hemoglobins

Tác giả: Luigi Vitagliano, Giovanna Bonomi, Antonio Riccio, Guido di Prisco, Giulietta Smulevich, and Lelio Mazzarella

Lĩnh vực: Biochemistry

Nội dung tài liệu: This study investigates the oxidation process of hemoglobins from Antarctic fish (Notothenioidei) using UV-visible spectroscopy and X-ray crystallography. The research reveals a common oxidation pathway among five different Antarctic fish hemoglobins, which exhibits distinct differences compared to hemoglobins from other vertebrates. Upon exposure to air, these hemoglobins readily form a significant amount of the low-spin hexacoordinated form, known as hemichrome. This hemichrome form can be reversibly transformed into carbomonoxy or deoxygenated forms using reducing agents. Spectroscopic analysis of fully oxidized species, obtained via ferricyanide treatment, shows the simultaneous presence of peaks corresponding to different hexacoordinated states, including aquomet and hemichrome. Crystallographic analysis of air-oxidized and ferricyanide-oxidized forms of Trematomus bernacchii hemoglobin indicates an α(aquomet)-β(bishistidyl-hemichrome) state, suggesting a unique oxidation pathway for the α and β chains in Antarctic fish hemoglobins. These structures are found to be intermediate between the physiological R and T hemoglobin states, offering insights into this intermediate state.

Mục lục chi tiết:

• Experimental Procedures
• Spectroscopic analyses
• Crystallographic studies
• Results
• Spectroscopic studies of the oxidation process of AFHbs
• Chemical oxidation of AFHbs
• Crystallographic studies on the oxidized forms of HbTb
• Discussion
• Acknowledgements
• References