Heme reactivity is uncoupled from quaternary structure in gel-encapsulated hemoglobin: a resonance Raman spectroscopic study.

ABSTRACT: Encapsulation of hemoglobin (Hb) in silica gel preserves structure and function but greatly slows protein motion, thereby providing access to intermediates along the allosteric pathway that are inaccessible in solution. Resonance Raman (RR) spectroscopy with visible and ultraviolet laser excitation provides probes of heme reactivity and of key tertiary and quaternary contacts. These probes were monitored in gels after deoxygenation of oxyHb and after CO binding to deoxyHb, which initiate conformational change in the R-T and T-R directions, respectively. The spectra establish that quaternary structure change in the gel takes a week or more but that the evolution of heme reactivity, as monitored by the Fe-histidine stretching vibration, ν(FeHis), is completed within two days, and is therefor

SUBMITTER: Jones EM 

PROVIDER: S-EPMC3307588 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature