ISSN:
1432-1327
Keywords:
Key words Myoglobin
;
Carbonmonoxyheme
;
Density functional theory
;
Tilting/bending energetics
;
CO/O2 discrimination
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract High-quality nonlocal density functional calculations have been carried out on the deformability of Fe(II)CO and Fe(III)CN units in model compounds of heme proteins. The results confirm our previous finding with a local functional that the Fe(II)CO unit is significantly deformable with respect to tilting and bending. This deformability stems in large part from a large, negative interaction constant between the FeC tilt and FeCO bend coordinates. The Fe(III)CN unit is also significantly deformable, but in this case the deformability results from a very small Fe(III)CN bend force constant and the ability of the cyano nitrogen to act as a hydrogen bond acceptor. The prediction that the energetic penalty associated with deforming the Fe(II)CO unit is relatively modest indicates that such deformations are unlikely to be the dominant contributor to myoglobin's discrimation against CO in favor of O2.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750050166
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