Time-resolved analysis of oxygen-binding saturation and structural changes in the crystal of the giant hemoglobin

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K20971
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural biochemistry; Biophysics
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: Numoto Nobutaka 東京医科歯科大学, 難治疾患研究所, 助教 (20378582)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: ヘモグロビン / 協同性 / 構造変化 / X線結晶構造解析 / 顕微分光

Outline of Final Research Achievements

The oxygenated crystals of the giant hemoglobin (molecular mass of about 400 kDa) from an annelid Oligobrachia mashikoi were prepared and then the crystals were shifted to various intermediate rates of oxygen-binding saturation with the soaking method. The crystals were processed by the laser crystal processing machine and these optimally processed crystals permitted us to observe the simultaneous transition in both oxygen dissociation and three-dimensional structure by microspectrophotometry and X-ray diffraction method in a time-resolved manner. The results suggest that while the giant hemoglobin changes from the oxygenated to the deoxygenated state, the local tertiary structural changes occur from a relatively early stage of oxygen dissociation, whereas the quaternary structural change across the molecule occurs a late stage of oxygen dissociation.

Free Research Field

構造生物化学