molecular modeling analysis of charge density and heat of fornation by pm3 method as well as c, h nmr and 2d-nmr measurements of histidine (substrate) and some of its derivatives as histidine decarboxylase inhibitors were performed. it was established that the atom, usually nitrogen, which forms internal aldimine with pyridoxal5 -phosphate (plp), (coenzyme), has negative and almost equal charge...

The urinary excretion, the intestinal absorption, and the elimination of histidine from blood were studied in two patients with Hartnup disease. On standard diet the patients lost a great proportion of the dietary histidine in the urine, whereas the fecal loss was negligible. A high oral dose of L-histidine gave only a slight increase in plasma histidine and no increase in fecal histidine, but ...

The objective of this research was to develop a kinetic-spectrophotometric method for the determination microquantities L-histidine in pure form and dietary supplements. based on kinetics ampicillin degradation by Ni(II) ion as catalyst presence strongly alkaline medium. rate reaction monitored spectrophotometrically measuring increase absorbance at 265 nm function time. same approach used inve...

in the present work, an extensive theoretical calculation study on histidine-histidine dipeptide in gas phase is done by using dft method with gaussian 98 program. through investigations on the molecular geometries of this molecule it is found that there is six rings in the molecules not two rings. the presence of four intramolecular hydrogen bonds is responsible for the formation of additional...

in this paper, the ultrasonic absorption of amino acids was measured using a small cylindrical resonator at physiological ph and 25°c and a concentration of 0.1. m. the absorption of mixtures of some amino acids was also measured. in the case of cysteine-histidine, the absorption of mixtures is much larger (more than twice) than the summation of absorption of the individual amino acid. this may...

Complexes of histidine with Co( 11) in aqueous solution have been examined by proton magnetic resonance spectroscopy. Coordinate interaction of histidine with paramagnetic Co( 11) produces large contact interaction shifts in the histidine proton resonance spectra. Four histidine-Co( 11) complexes have been distinguished : a weak 1: 1 histidine-Co(I1) complex a t low pH ( < 4 ) in which only the...

Molecular modeling analysis of charge density and heat of fornation by PM3 method as well as C, H NMR and 2D-NMR measurements of histidine (substrate) and some of its derivatives as histidine decarboxylase inhibitors were performed. It was established that the atom, usually nitrogen, which forms internal aldimine with pyridoxal5 -phosphate (PLP), (coenzyme), has negative and almost equal ...

the calcium binding sites of bakers&apos; yeast transketolase (tk) was elucidated by estimating the pka values of the functional groups that bind to calcium. these pka&apos;s were found to be 6.25 and 7.2 relating to the pka&apos;s of the two immidazol moieties of histidine residues on the enzyme. the rate of the binding of calcium to the enzyme was obtained separately as a function of ph. maxi...

In the present study, we investigated the effects of histidine and vitamin C (alone or in combination) treatments against isoproterenol (a β-adrenergic receptor agonist)-induced acute myocardial infarction in rats. We used propranolol (a β-adrenergic receptor blocker) to compare the results. Rats were given intraperitoneal injections of histidine (40 mg kg-1) and vitamin C (40 mg kg<...