Active signed subunit differences in hemoglobin revealed by resonance Raman studies of selectively labeled tetramers

摘要

We report for the first time the low frequency resonance Raman (RR) spectra for hemoglobin reconstituted with methyl deuterated heme (Hb-d_(12)) and for the hybrids bearing the labeled heme in only one type of subunit; i.e. [α_(d12)β_(h12]_2 and [ 250L羅(h12)β_(d12)])]_2. The low frequency RR spectra are also reported for hemoglobin (Hb), bearing methine deuterared hemes in all four subunits (Hb-d_4) as well as for the hybrids containing the d_4- labeled heme in only one type of subunit; i.e. [α_(d4)β_(h4)]_2 and [α_(h4)β_(d4)]_2. Both low-spin (CO or O_2 ligated) derivatives and the fully reduced, deoxy forms have been studied. The entire set of spectral data has been analyzed using an internally consistent deconvolution procedure to identify modes which are associated with the α and β subunits.