Calculation of atom-centered partial charges for heme
Atom-centered partial charges are calculated for the Fe-heme in cytochrome P450cam for use in molecular dynamics simulations of polar substrates bound in the active site of the enzyme. Charges are fit to the electrostatic potential produced by ab initio UHF wavefunctions for an Fe-porphine model. Basis set dependence of these charges is observed using the LANL1DZ, LANL2DZ and augmented 6-31G levels of theory. Upon geometry optimization of the enzyme, these charge sets cause varying degrees of distortion of the porphyrin from its crystallographically observed conformation. Scaling the charges calculated from the augmented 6-31G basis by 75% reduces the heme distortion while preserving reasonable interactions with a polar substrate. A comparison of the calculated charges with other published values is presented.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 10165548
- Report Number(s):
- PNL-SA-24303; CONF-9405196-1; ON: DE94014447; CNN: Grant KP0402
- Resource Relation:
- Conference: 27. Jerusalem symposium in quantum chemistry and biochemistry,Jerusalem (Israel),23-26 May 1994; Other Information: PBD: May 1994
- Country of Publication:
- United States
- Language:
- English
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