TY - JOUR
T1 - Hydration of DNA bases and compounds containing small rings - A model for interactions of the ricin toxin A-chain. A theoretical ab initio study
AU - Zhanpeisov, Nurbosyn U.
AU - Leszczynski, Jerzy
N1 - Funding Information:
This work is sponsored in part by the Army High Performance Computing Research Center under the auspices of the Department of the Army, Army Research Laboratory cooperative agreement number DAAH04-95- 2-0003/ contract number DAAH04-95-C-0008, the con- tent of which does not necessarily reflect the position or policy of the government, and no official endorsement should be inferred and by NSF-EPSCOR Grant OSR-9452857. The Mississippi Center for Supercomput- ing Research is acknowledged for a generous allotment of computer time.
PY - 2001
Y1 - 2001
N2 - Ab initio quantum chemical calculations were performed for four neutral gas phase adenine and four pterin tautomers along with guanine and formycin bases. The water complexes of the lowest energy tautomers of these bases have been studied to mimic their interaction with the ricin toxin A chain (RTA). The water molecules create a full first hydration shell around the bases. Full geometry optimizations without any constraints on the planarity of these hydrated complexes were carried out at the HF/6-31G(d,p) level. Single point calculations were also performed at the correlated MP2/6-31G(d,p)//HF/6-31G(d,p) level of theory. Hydration energies were corrected for the basis set superposition error. Hydration energies of adenine and formycin are predicted to be lower (in magnitude) than those for the pterin and guanine. Due to these properties, two pterin tautomers can be considered as potentially useful inhibitors of RTA.
AB - Ab initio quantum chemical calculations were performed for four neutral gas phase adenine and four pterin tautomers along with guanine and formycin bases. The water complexes of the lowest energy tautomers of these bases have been studied to mimic their interaction with the ricin toxin A chain (RTA). The water molecules create a full first hydration shell around the bases. Full geometry optimizations without any constraints on the planarity of these hydrated complexes were carried out at the HF/6-31G(d,p) level. Single point calculations were also performed at the correlated MP2/6-31G(d,p)//HF/6-31G(d,p) level of theory. Hydration energies were corrected for the basis set superposition error. Hydration energies of adenine and formycin are predicted to be lower (in magnitude) than those for the pterin and guanine. Due to these properties, two pterin tautomers can be considered as potentially useful inhibitors of RTA.
KW - Ab initio calculations
KW - DNA bases
KW - Hydration
KW - Molecular interactions
KW - Ricin
UR - http://www.scopus.com/inward/record.url?scp=0000749244&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0000749244&partnerID=8YFLogxK
U2 - 10.1023/A:1016644509369
DO - 10.1023/A:1016644509369
M3 - Article
AN - SCOPUS:0000749244
VL - 12
SP - 121
EP - 126
JO - Structural Chemistry
JF - Structural Chemistry
SN - 1040-0400
IS - 2
ER -