Common signal transduction mechanisms, generally referred to as histidine-to-aspartate (His-to-Asp) phosphorelays (or two-component regulatory systems), are involyed in a wide variety of cellular responses to environmental stimuli.i} Such a His-toAsp phosphorelay system generally consists of two or more common signal transducers; a sensor with histidine (His)-kinase activity, a histidine-contai...

Urocanate but not histidine was able to induce formation of histidine-degrading enzymes in a histidine ammonia-lyase-deficient mutant of Pseudomonas aeruginosa. The results, in conjunction with others reported previously, indicate that urocanate, the first intermediate, is the physiological inducer of the pathway.

The present study was carried out to investigate whether the dietary histidine requirement to reduce cataract development is higher than that for growth in Atlantic salmon smolts (Salmo salar L.) after seawater transfer and whether dietary vegetable oils contribute to cataractogenesis. Duplicate groups of salmon smolts were fed ten experimental diets with either fish oil (FO) or a vegetable oil...

L-Histidine labeled with deuterium at the C-5' position of the imidazole ring, L-[5'-2H]histidine (His-5'-D), was used as a probe for investigating a stepwise reversible mechanism via a carbanion intermediate in the elimination of ammonia catalyzed by histidine ammonia-lyase (EC 4.3.1.3). The labeled L-histidine (His-5'-D) (2.45 mM) was incubated with histidine ammonia-lyase (200 units) from Ps...

l-Histidine and, to a lesser degree, l-phenylalanine at concentrations of 10(-4)m inhibit the growth of leaky mutants (bradytrophs) of Bacillus subtilis that are deficient in the synthesis of p-hydroxyphenylpyruvate, the first intermediate specific to tyrosine synthesis. The inhibition can be overcome by growth factor amounts of l-tyrosine and p-hydroxyphenylpyruvate. Histidine and phenylalanin...

L-histidine is one of the essential amino acids for humans, and it plays a critical role as a component of proteins. L-histidine is also important as a precursor of histamine. Brain histamine is synthesized from L-histidine in the presence of histidine decarboxylase, which is expressed in histamine neurons. In the present study, we aimed to elucidate the importance of dietary L-histidine as a p...

Caulobacter crescentus has an inducible pathway which is responsible for the degradation of histidine. Induction of this pathway occurs in the presence of both glucose and ammonia. Growth yield experiments indicate that only two of the three available nitrogens are used for growth suggesting that formamide may be produced as a waste product. However, formamide was not detected in the culture fl...

Organometallic complexes offer potential for design as anticancer drugs. A quantitativemodel that discriminates anticancer compounds from the inactive ones in a training series wasEquilibrium of the reaction of molybdenum (VI) with l-histidine have been studiedin aqueous solutions at pH range of 4-8, using spectrophotometry and optical rotationmethods at constant ionic strength of 0.15 mol.lit-...

Abstract Catalytic triads, composed of a serine or cysteine nucleophile, histidine, and third triad residue (typically Asp/Glu/Asn), are common in enzyme active sites catalyze wide variety chemical reactions. Two types triads can be distinguished: We refer to them as Nδ‐ Nϵ‐configured, depending on whether the histidine imidazole Nδ Nϵ atom is close nucleophile Oγ/Sγ. In this study, we have ana...