Fourier Deconvolution Methods for Resolution Enhancement in Continuous-Wave EPR Spectroscopy.

An overview of resolution enhancement of conventional, field-swept, continuous-wave electron paramagnetic resonance spectra using Fourier transform-based deconvolution methods is presented. Basic steps that are involved in resolution enhancement of calculated spectra using an implementation based on complex discrete Fourier transform algorithms are illustrated. Advantages and limitations of the method are discussed.

Phase II studies of polymer-doxorubicin (PK1, FCE28068) in the treatment of breast, lung and colorectal cancer.

Phase I studies of [N-(2-hydroxypropyl)methacrylamide] (HPMA) copolymer-doxorubicin previously showed signs of activity coupled with 5-fold decreased anthracycline toxicity in chemotherapy-refractory patients. Here we report phase II studies using a similar material (FCE28068) in patients with breast (n=17), non-small cell lung (NSCLC, n=29) and colorectal (n=16) cancer. Up to 8 courses of PK1 (280 mg/m(2) doxorubicin-equivalent) were given i.

Reaction of AdoMet with ThiC generates a backbone free radical.

ThiC is an [4Fe-4S] cluster protein that catalyzes the formation of 4-amino-5-hydroxymethyl-2-methylpyrimidine. EPR spectroscopic studies demonstrate that, upon interaction with AdoMet, active ThiC from Salmonella enterica generates a persistent free radical on the alpha-carbon of an amino acid residue. The EPR properties of the radical are consistent with any residue other than a Gly or Ala.

Identification of the substrate radical intermediate derived from ethanolamine during catalysis by ethanolamine ammonia-lyase.

Rapid-mix freeze-quench (RMFQ) methods and electron paramagnetic resonance (EPR) spectroscopy have been used to characterize the steady-state radical in the deamination of ethanolamine catalyzed by adenosylcobalamin (AdoCbl)-dependent ethanolamine ammonia-lyase (EAL). EPR spectra of the radical intermediates formed with the substrates, [1-13C]ethanolamine, [2-13C]ethanolamine, and unlabeled ethanolamine were acquired using RMFQ trapping methods from 10 ms to completion of the reaction. Resolved 13C hyperfine splitting in EPR spectra of samples prepared with [1-13C]ethanolamine and the absence of such splitting in spectra of samples prepared with [2-13C]ethanolamine show that the unpaired electron is localized on C1 (the carbinol carbon) of the substrate.