ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Nitrosyl hemoglobin (Hb) from carp shows a resonance Raman spectrum characteristic of 6-coordinate (NO) heme. Switching the quaternary structure from R to T by addition of insitol hexaphosphate (IHP) at pH 5.8 does not produce a 5-coordinate spectrum, as it does for human Hb. Only intensity changes are seen for bands at ∼490, 387 and 357 cm-1, indicating a subtle alteration in the porphyrin-protein interaction. In carp deoxy Hb, IHP addition produced a shift of the Fe-ImH (ImH = imidazole) stretching mode, from 223 to 214 cm-1. The band remained symmetrical, indicating essential equivalence of the subunits. This is in contrast to human deoxy Hb for which the R-T shift in the Fe-ImH frequency is much greater in the α than the β chains. In carp Hb all the Fe-ImH bonds appear to be weakened in the T state, but to an extent insufficient to induce rupture upon binding NO.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250140307
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