1994 Fiscal Year Final Research Report Summary
Relationship between structural changes of protein and function of abnormal hemoglobin.
| Project/Area Number |
05670116
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
General medical chemistry
|
|---|
| Research Institution | Kanazawa University |
|---|
Principal Investigator |
NAGAI Masako Kanazawa University, School of Allied Medical Professions, Professor, 医療技術短期大学, 教授 (60019578)
|
|---|
| Project Period (FY) |
1993 – 1994
|
| Keywords | Hemoglobin / Ultraviolet Resonance Raman / Circular Dichroism / Protein Structure / Function of Hemoglobin / Aromatic Amino Acids |
|---|
| Research Abstract |
X-ray crystallographic studies have shown that the deoxy and liganded forms of hemoglobin (Hb) poseesee two distinct quaternary structures named T-and R-states, respectively. Cooperative oxygenation to Hb has been explained in terms of a reversible transition between the two quaternary structures upon partial ligation to the four hemes. Environmental changes of tyrosine (Tyr) and tryptophan (Trp) residues of Hb upon its T-to-R transition of quaternary structure was ivestigated with ultraviolet resonance Raman (UVRR) spectroscopy and circular dichroism (CD) . To characterize the spectral change of Trp beta37 at alpha_1beta_2 interface due to the quaternary structure transition, the UVRR spectra of Hb A were compared with the corresponding spectra of Hb Hirose in which Trp beta37 is replaced by serine (Ser) . Difference spectrum between deoxyHb A and deoxyHb Hirose gave rise to only Trp RR bands, which were reasonably ascribed to Trp beta37 in deoxyHb A.Comparison of the Hb A-Hb Hirose difference spectra in the oxy and deoxy states revealed that the oxygenation-induced changes of Trp RR bands arose mostly from Trp beta37 and the remaining minor part from Trp beta15, demonstrating that Trp beta37 plays a pivotal role in the quaternary structural change in Hb A.
|
