Rebinding Dynamics of CO Following Photodissociation of 4.0 M Guanidine HCl-Denatured Carbonmonoxyhemoglobin

Bulletin of the Korean chemical society

Jooyoung Kim¹  Jaeheung Park¹  Manho Lim¹  Taegon Lee¹  Salina A Chowdhurry¹ 

关键词: CO rebinding;    Hemoglobin;    Guanidine HCl;    Femtosecond vibrational spectroscopy;    Denaturation;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Femtosecond vibrational spectroscopy was used to probe the dynamics of CO rebinding to hemoglobin (Hb), denatured by 4.0 M GdnHCl in D2O at 283 K, after photolysis of HbCO. The stretching mode of 13CO bound to the denatured Hb13CO showed a single band centered at 1922 cm-1, indistinguishable from that of denatured Mb13CO. Geminate rebinding of CO to the denatured Hb was accelerated more than 1000 times, suggesting that the native structure of the Hb is required to suppress efficient geminate rebinding of CO, as is the case in Mb. The geminate yield and rate for CO rebinding are almost the same in both the denatured Hb and Mb. Similarity in the equilibrium spectrum and rebinding dynamics of CO indicates that the state of the denatured Hb is very similar to that of the denatured Mb. In the denatured Hb, quaternary contact of the protein is likely severed, with the denatured protein existing as an independent subunit much like Mb.

【 授权许可】

Unknown