Paul E. Fagerness

13 C n.m.r. evidence for a new intermediate, pre-uroporphyrinogen, in the enzymic transformation of porphobilinogen into uroporphyrinogens I and III

Evidence is presented from 13C n.m.r. spectroscopic studies which indicates that the enzymic transformation of porphobilinogen into uroporphyrinogens I and III occurs through a transient free intermediate, pre-uroporphyrinogen, produced by porphobilinogen deaminase (uroporphyrinogen I synthetase).

Inhibition of trypsin by carbobenzyloxylysyl chloromethyl ketone: 13C NMR and x-ray diffraction analyses of the enzyme-inhibitor complex

Abstract Comparison of the X-ray diffraction data and both solution and solid (CPMAS) NMR spectra for the covalent adduct of trypsin and carbobenzyloxylysyl chloromethyl ketone provides unequivocal evidence that the serine-195 hydroxyl group of the enzyme forms a covalent bond with the carbonyl group of the bound inhibitor. This result provides important correlation of solution and solid-state geometry in such adducts.

Uniformly 13C-enriched substrates as n.m.r probes for metabolic events in vivo. Application of double quantum coherence to a biochemical problem

Glycolysis in Escherichia coli has been monitored in vivo by 13C n.m.r. spectroscopy and the biochemical pathways involved in succinate biosynthesis have been evaluated by analysis of the complex resonance signals, using double quantum coherence.

The carbon-13 and nitrogen-15 nuclear magnetic resonance spectra of uroporphyrinogens I and III

Abstract Due to their sensitivity to light and air, porphyrinogens are not normally isolated, but are routinely analyzed by oxidation to the corresponding porphyrin. We report herein the 13 C- and 15 N-NMR spectra of uroporphyrinogens I and III in their “native state”, multiply labelled with 13 C and 15 N, and at natural abundance ( 13 C only).

N.m.r. studies of enzyme mechanism. Comparison of the crystal structure and solid state 13C and 15N n.m.r. spectra of a carboxypeptidase A complex with glycyl tyrosine

It is shown that solid state n.m.r. spectroscopy can be used to determine the extent of cleavage of the scissile amide bond in glycyl tyrosine, a slow substrate for the enzyme carboxypeptidase A in the crystalline enzyme substrate complex.

Direct observation of porphyrinogen biosynthesis in living cells by 13C n.m.r. spectroscopy

The metabolism of 13C-labelled substrates and of glucose has been observed directly in live cells by proton-decoupled 13C-Fourier transform n.m.r. spectroscopy.