Abstract

Utilizing a dinuclear iron center tyrosyl radical cofactor, ribonucleoside diphosphate reductase (RNR) from E. coli catalyzes the conversion of nucleoside diphosphates to deoxynucleoside diphosphates. 2'-(E)-Fluromethylene-2'-deoxycytidine 5'-diphosphate (FMCDP) has recently been shown to be a near stoichiometric mechanism based inhibitor for this enzyme. Loss of the essential tyrosyl radical and formation of a new nucleotide based radical accompany inactivation. In order to gain insight into the structure of this radical, [6'-13C]-FMCDP has been synthesized, and the EPR spectrum of the radical resulting from its incubation with RDPR has been resolved. Simulation of the resulting spectrum provides unambiguous evidence that this new radical is allylic in nature, and is derived from H0133'-hydrogen atom abstraction mediated by RDPR.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
3P41RR002583-13S1
Application #
6121172
Study Section
Project Start
1998-05-05
Project End
2000-04-30
Budget Start
1998-10-01
Budget End
1999-09-30
Support Year
13
Fiscal Year
1999
Total Cost
Indirect Cost

  Institution

Name
Albert Einstein College of Medicine
Department
Type
DUNS #
009095365
City
Bronx
State
NY
Country
United States
Zip Code
10461

  Publications

Colaneri, M J; Vitali, J; Peisach, J (2000) Electron spin-echo envelope modulation study of multicrystalline Cu(2+)-insulin: effects of Cd(2+) on the nuclear quadrupole interaction of the Cu(2+)-coordinated imidazole remote nitrogen. Biochemistry 39:584-91
Lee, H C; Goroncy, A K; Peisach, J et al. (2000) Demonstration of a conserved histidine and two water ligands at the Mn2+ site in Diocleinae lectins by pulsed EPR spectroscopy. Biochemistry 39:2340-6
Sam, J W; Takahashi, S; Lippai, I et al. (1998) Sequence-specific changes in the metal site of ferric bleomycin induced by the binding of DNA. J Biol Chem 273:16090-7
Magliozzo, R S; Marcinkeviciene, J A (1997) The role of Mn(II)-peroxidase activity of mycobacterial catalase-peroxidase in activation of the antibiotic isoniazid. J Biol Chem 272:8867-70
Nersissian, A M; Mehrabian, Z B; Nalbandyan, R M et al. (1996) Cloning, expression, and spectroscopic characterization of Cucumis sativus stellacyanin in its nonglycosylated form. Protein Sci 5:2184-92
Gasdaska, J R; Law, J H; Bender, C J et al. (1996) Cockroach transferrin closely resembles vertebrate transferrins in its metal ion-binding properties: a spectroscopic study. J Inorg Biochem 64:247-58
Tipton, P A; Quinn, T P; Peisach, J et al. (1996) Role of the divalent metal ion in the NAD:malic enzyme reaction: an ESEEM determination of the ground state conformation of malate in the E:Mn:malate complex. Protein Sci 5:1648-54
Coffino, A R; Peisach, J (1996) Simulation of Mn (II) EPR spectra using a full spin-Hamiltonian approach. J Magn Reson B 111:127-34
Parast, C V; Wong, K K; Lewisch, S A et al. (1995) Hydrogen exchange of the glycyl radical of pyruvate formate-lyase is catalyzed by cysteine 419. Biochemistry 34:2393-9
Theodorakis, J L; Garber, E A; McCracken, J et al. (1995) A chemical modification of cytochrome-c lysines leading to changes in heme iron ligation. Biochim Biophys Acta 1252:103-13

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