Straight-Chain Alkyl Isocyanides Open the Distal Histidine Gate in Crystal Structures of Myoglobin,

Coordination structure of the ferric heme iron in engineered distal histidine myoglobin mutants.

Recombinant human myoglobin mutants with the distal His residue (E7, His64) replaced by Leu, Val, or Gln residues were prepared by site-directed mutagenesis and expression in Escherichia coli. Electronic and coordination structures of the ferric heme iron in the recombinant myoglobin proteins were examined by optical absorption, EPR, 1H NMR, magnetic circular dichroism, and x-ray spectroscopy. ...

Nucleophilicity parameters for alkyl and aryl isocyanides.

Ultrafast dynamics of myoglobin without the distal histidine: stimulated vibrational echo experiments and molecular dynamics simulations.

Ultrafast protein dynamics of the CO adduct of a myoglobin mutant with the polar distal histidine replaced by a nonpolar valine (H64V) have been investigated by spectrally resolved infrared stimulated vibrational echo experiments and molecular dynamics (MD) simulations. In aqueous solution at room temperature, the vibrational dephasing rate of CO in the mutant is reduced by approximately 50% re...

Effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying evaluated using a non-invasive breath test in conscious rats

AIM Some amino acids been known to influence gastric emptying. Thus we have evaluated the effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying. MATERIALS AND METHODS Gastric emptying was evaluated in rats after feeding with Racol (nutrient formulae) containing [1-(13)C] acetic acid. Using a breath test, the content of (13)CO2 in th...

Equilibrium binding of alkyl isocyanides to human hemoglobin.

The reactions of human hemoglobin with a series of 13 alkyl isocyanides have been examined in equilibrium titration experiments at pH 7, 20 degrees C. The ligands include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, (+)- and (-)-sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, and benzyl isocyanides. All of these compounds exhibit sigmoidal binding curves; however, the amount of...