William M. Westler

1H NMR of intact muscle at 11 T

1H NMR spectra of intact frog, and chicken skeletal muscles, were recorded at 470 MHz with the Plateau and Guéron pulse sequence for the suppression of water [(1982) J. Am. Chem. Soc. 104, 7310]. Only a few transients were required to resolve the resonances from the protons of muscle metabolites. The previously unobserved exchangeable protons of muscles were also recorded and thereby phosphocreatine and creatine could be measured simultaneously. During aging of dissected frog muscle, changes in levels of phosphocreatine, creatine and lactic acid, and the decrease in the intracellular pH were followed by 1H NMR.

Reassignments in the 1H NMR spectrum of flavin adenine dinucleotide by two-dimensional homonuclear chemical shift correlation

Abstract The ribitol 1 H NMR proton reasonances for flavin adenine dinucleotide have been assigned using homonuclear two dimensional NMR spectroscopy.

Iron-Sulfur Proteins: Investigations of Hyperfine-Shifted Hydrogen, Carbon, and Nitrogen Resonances

Iron-sulfur proteins are present in almost all living organisms. They are characterized by one or more iron ions ligated to inorganic sulfur and/or cysteine sulfur. Rubredoxin-type clusters contain a single iron ligated to four cysteines and have no inorganic sulfur. All other types of iron-sulfur protein contain two or more irons plus inorganic sulfur. Four types of iron-sulfur centers with cysteine ligands to the protein have been characterized by x-ray crystallography; they can be distinguished by the number of iron and inorganic sulfur atoms as: [lFe], [2Fe-2S], [4Fe-4S], and [3Fe-4S. An additional type of iron-sulfur center has been shown to have one carboxylic acid ligand, and Rieske centers are believed to contain a [2Fe-2S] cluster ligated to two cysteines and two histidines. Some iron-sulfur proteins contain more than one Fe-S center, and these may be of the same or mixed types. Rubredoxins and all ferredoxins display electron- carrier activity but no classical enzyme function. Some iron-sulfur proteins, such as endonuclease III and aconitase, have been shown to play roles in enzymatic catalysis rather than in redox chemistry (Hentze & Argos, 1991). Other Fe-S proteins are involved in the regulation of transcription (Roualt et al., 1991).