SEARCH · Search PubMed

Results for “HISTIDINE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMed2000

Importance of histidine residues for the function of the human liver UDP-glucuronosyltransferase UGT1A6: evidence for the catalytic role of histidine 370.

The human UDP-glucuronosyltransferase isoform UGT1A6 catalyzes the nucleophilic attack of phenolic xenobiotics on glucuronic acid, leading to the formation of water-soluble glucuronides. Based on the irreversible inhibition of the enzyme activity by the histidyl-selective reagent diethyl pyrocarbonate (DEPC), histidine was suggested to play a key role in the glucuronidation reaction. Therefore, the role of four strictly conserved histidine residues (His38, His361, His370, and His485) in the glucuronidation of 4-methylumbelliferone, as reporter substrate, was examined using site-directed mutagenesis. For this purpose, stable heterologous expression of wild-type and mutant UGT1A6 was achieved in the yeast Pichia pastoris. Replacement of histidine residues by alanine or glutamine led to fully inactive H38A, H38Q, and H485A mutants. Substitution of His361 by alanine affected the interaction of the enzyme with the cosubstrate, as indicated by a 4-fold increase in the K(m) value toward UDP-glucuronic acid. Interestingly, H370A mutant presented a severely impaired catalytic efficiency (with a V(max) value approximately 5% that of the wild-type), whereas conservative substitution of His370 by glutamine (H370Q) led to a significant restoration of activity. Whereas H361A was inactivated by DEPC as the wild-type enzyme, this chemical reagent only produced a minor effect on either H370Q or H370A mutant, providing evidence that His370 is probably the reactive histidine residue targeted by DEPC. The dramatic changes in catalytic efficiency on substitution of His370 by alanine and the ability of glutamine to function in place of histidine along with a weak sensitivity of these mutants to DEPC strongly suggest that His370 plays a catalytic role in the glucuronidation reaction.

Alanine↗

PubMed1974

Cross-pathway regulation: histidine-mediated control of histidine, tryptophan, and arginine biosynthetic enzymes in Neurospora crassa.

In Neurospora crassa, histidine starvation of histidine mutants resulted in derepression of histidine, tryptophan, and arginine biosynthetic enzymes. The same tripartite derepression occurred in wild-type strain 74A when it was grown in medium supplemented with 3-amino-1,2,4-triazole, an inhibitor of histidine biosynthesis. Histidine-mediated derepression of tryptophan and arginine biosynthetic enzymes was not due to a lowered intracellular concentration of tryptophan or arginine, respectively. A discussion of possible mechanisms and of similar studies in prokaryotic and eukaryotic organisms is presented.

Amitrole↗

PubMed1985

The histidine-rich glycoprotein of serum has a domain rich in histidine, proline, and glycine that binds heme and metals.

Histidine-rich glycoprotein (HRG) from rabbit serum was digested with plasmin, reduced, and carboxymethylated, and the fragments produced were resolved by reverse-phase high-performance liquid chromatography. Several peptide fractions were obtained that contain unusually high contents of histidine, proline, and glycine. One His-Pro-Gly-rich peptide (apparent Mr 30 000) was obtained in sufficient yield and purity for further study. This peptide is 29 mol % histidine, 37% proline, and 16% glycine, indicating that most of these three amino acids are located in one region of HRG. The peptide contains 9% by weight carbohydrate and is devoid of tyrosine or tryptophan. The far-ultraviolet circular dichroism spectrum of the peptide has a minimum at 203 nm, indicating that the peptide contains polyproline II helical sections. The peptide represents a binding domain of HRG since it retains much of the ability of intact HRG to bind heme and metals including Zn2+, Ni2+, and Cu2+. As with the parent HRG molecule, interaction of the peptide with heme and metals is dependent on pH and intact histidine residues.

Animals↗

PubMed1990

[Histidine decarboxylase activity and free histidine and histamine levels in fish meat].

The activity of histidine decarboxylase was determined in the meat of fresh fish (mackerel, herring, sprat) and in fish stored for 48 hours at +4 degrees C and +18 degrees C. The activity was determined measuring the increase of histamine released from a controlled amount of histidine. A rise was demonstrated in the activity of these enzymes in the meat of fish stored for 48 hours at +18 degrees C. As a result of this activity the histamine level increased considerably, particularly in the meat of these fish species in which the free histidine content exceeds 100 mg/100 g of tissue. The mean activity of histidine decarboxylase obtained in the meat of frozen and fresh fish expressed in nmol of histamine/min/mg of protein was 0.11 +/- 0.06 for mackerel meat, 0.10 +/- 0.04 for herring, and 0.08 +/- 0.04 for sprat.

Animals↗

PubMed2006

Two conserved non-canonical histidines are essential for activity of the cbb (3)-type oxidase in Rhodobacter capsulatus: non-canonical histidines are essential for cbb (3)-type oxidase activity in R. capsulatus.

Cytochrome cbb (3) oxidase, a member of the heme-copper oxidase superfamily, catalyses the reduction of oxygen to water and generates a proton gradient. Cytochrome c oxidases are characterized by a catalytic subunit (subunit I) containing two hemes and one copper ion ligated by six invariant histidine residues, which are diagnostic of heme-copper oxidases in all type of the heme-copper oxidase superfamily. Alignments of the amino acid sequences of subunit I (FixN or CcoN) of the cbb (3)-type oxidases show that catalytic subunit also contains six non-canonical histidine residues that are conserved in all CcoN subunits of the cbb (3) oxidase, but not the catalytic subunits of other members of heme-copper oxidases superfamily. The function of these six CcoN-specific conserved histidines of cbb (3)-type oxidase in R. capsulatus is unknown. To analyze the contribution of the two invariant histidines of CcoN, H300 and H394, in activity and assembly of the Rhodobacter capsulatus cbb (3)-type oxidase, they were substituted for valine and alanine, respectively by site-directed mutagenesis. H300V and H394A mutations were analyzed with respect to their activity and assembly. It was found that H394A mutation led to a defect in the assembly of both CcoP and CcoO in the membrane, which results in almost complete loss of activity and that although the H300V mutant is normally assembled in the membrane and retain their stability, its catalytic activity is significantly reduced when compared with wild-type oxidase.

Amino Acid Sequence↗

PubMed1989

Formation of intermolecular and intramolecular hydrogen bonds in histidine-binding protein J of Salmonella typhimurium upon binding L-histidine. A proton nuclear magnetic resonance study.

Histidine-binding protein J of Salmonella typhimurium has been chosen as a model system for a proton nuclear magnetic resonance spectroscopic investigation of binding protein-ligand interaction. This interaction is involved in the recognition step of the osmotic shock-sensitive active transport systems. When J protein binds L-histidine, four new, low-field, exchangeable proton resonances appear in the region +7 to +12 parts per million downfield from the water proton resonance (or +11.7 to +16.7 parts per million downfield from the methyl proton resonance of 2,2-dimethyl-2-silapentane-5-sulfonate). Due to their chemical shift range and other properties, they indicate the formation of both intra- and intermolecular hydrogen bonds. Experiments with 15N-labeled compounds confirm this conclusion. The specificity of the hydrogen-bond formation is demonstrated by observing the effects of substrate analogs, temperature, pH, and mutations on the exchangeable proton resonances. Proton-proton nuclear Overhauser effect measurements suggest that two of these exchangeable proton resonances (at +7.2 and +10.6 parts per million from H2O) are most likely from intramolecular hydrogen-bonded protons, while the other two (at +7.1 and +9.5 parts per million from H2O) are intermolecular hydrogen bonds. Our finding of L-histidine-induced hydrogen-bond formation in histidine-binding protein J in the solution state is an excellent demonstration of the production of specific conformational changes in a periplasmic binding protein upon binding of ligand.

Carrier Proteins↗

PubMed2006

Flow-injection determination of L-histidine with an immobilized histidine oxidase from Brevibacillus borstelensis KAIT-B-022 and chemiluminescence detection.

A chemiluminometric flow injection analytical system for the quantitation of L-histidine is described. Histidine oxidase (EC 1.4.3.-) from Brevibacillus borstelensis KAIT-B-022 was immobilized on tresylated poly(vinyl alcohol) beads and packed into a stainless-steel column. The hydrogen peroxide produced was detected chemiluminometrically by a flowthrough sensor containing immobilized peroxidase (EC 1.1 1.1.7). The maximum sample throughput was 10 h(-1). The calibration graph was linear from 0.05 to 5 mM; the detection limit (signal to noise ratio = 3) was 0.01 mM. The activity of immobilized histidine oxidase reduced to 65% of the initial value after 350 injections. The system was applied to the determination of L-histidine in fish meat, such as salmon, tunny, bonito, and mackerel.

Bacillus↗

PubMed1982

Effect of alpha-monofluoromethyl histidine, an irreversible inhibitor of histidine decarboxylase, on gestation in mice.

Chronic administration of alpha-monofluoromethyl histidine, a specific inhibitor of histidine decarboxylase, to pregnant mice blocked histidine decarboxylase activity and markedly depleted histamine levels in 18-day-old foetuses and in newborn mice. Such treatment had no effect on implantation or embryonic development or parturition suggesting that de novo synthesis of histamine is not a significant factor in these processes in the mouse.

Animals↗

PubMed1977

Potential histidine decarboxylase inhibitors. 1. alpha- and beta-substituted histidine analogues.

Histidine analogues with alkyl substitution at Calpha and Cbeta were prepared as potential inhibitors of specific histidine decarboxylase. Activity was assessed in vitro using extracts of rat pyloric stomach and a radioisotopic assay of 14CO2 evolved from carboxyl-14C-labeled histidine. alpha-Substituted analogues (C2-C4) including 2-hydroxyethyl were less potent than alpha-methylhistidine; the alpha-n-butyl analogue was completely inactive at 10(-3) M. Similarly, beta,beta-dimethylhistidine and homohistidine failed to exhibit activity at 10(-3) M.

Animals↗

PubMed2004

The C-terminus of rat L-histidine decarboxylase specifically inhibits enzymic activity and disrupts pyridoxal phosphate-dependent interactions with L-histidine substrate analogues.

Full-length rat HDC (L-histidine decarboxylase) translated in reticulocyte cell lysate reactions is inactive, whereas C-terminally truncated isoforms are capable of histamine biosynthesis. C-terminal processing of the approximately 74 kDa full-length protein occurs naturally in vivo, with the production of multiple truncated isoforms. The minimal C-terminal truncation required for the acquisition of catalytic competence has yet to be defined, however, and it remains unclear as to why truncation is needed. Here we show that approximately 74 kDa HDC monomers can form dimers, which is the conformation in which the enzyme is thought to be catalytically active. Nevertheless, the resulting dimer is unable to establish pyridoxal phosphate-dependent interactions with an L-histidine substrate analogue. Protein sequences localized to between amino acids 617 and 633 specifically mediate this inhibition. Removing this region or replacing the entire C-terminus with non-HDC protein sequences permitted interactions with the substrate analogue to be re-established. This corresponded exactly with the acquisition of catalytic competence, and the ability to decarboxylate natural L-histidine substrate. These studies suggested that the approximately 74 kDa full-length isoform is deficient in substrate binding, and demonstrated that C-terminally truncated isoforms with molecular masses between approximately 70 kDa and approximately 58 kDa have gradually increasing specific activities. The physiological relevance of our results is discussed in the context of differential expression of HDC isoforms in vivo.

Alternative Splicing↗

PubMedDate not supplied

[Effect of histidine analogs and histidyl-containing dipeptides on the decarboxylase activity of Micrococcus sp. n. histidine decarboxylase].

L-Histidinol and L-histidine hydroxamate were shown to inhibit competitively histidine decarboxylase from Micrococcus sp. n responsible for histamine biosynthesis. Constants of their inhibitory effect were found. Histidyl-containing dipeptides did not exhibit the pronounced inhibitory effect. The rate of inhibition was increased after esterification of histidyl dipeptide. Kinetics of the histidine decarboxylase inhibition by L-histidyl-L-leucine methyl ester was studied.

Carboxy-Lyases↗

PubMed1979

Histidine sensitive variant of the blue-green alga Nostoc muscorum: response to corepressors of histidine biosynthesis.

A model has been proposed to account for growth inhibition by L-histidine in a variant strain of Nostoc muscorum. This strain has been characterized for its response to 3-amino-1,2,4-triazole and 1,2,4-triazole-3-alanine known to act as false core-pressors of the histidine biosynthesis genes. The histidine sensitive strain retained its sensitivity to triazole alanine while the inhibitory effects of aminotriazole were much reduced indicating a change in regulation of his genes. The probable interactions between nif and his genes in cyanobacteria (blue-green algae) have been discussed.

Cyanobacteria↗

PubMed1983

Mammalian histidine decarboxylase: effect by protein kinase on mouse mastocytoma histidine decarboxylase.

Mouse mastocytoma histidine decarboxylase is decreased in activity when, in crude preparations, incubated with a cAMP-dependent protein kinase. This effect was not seen with purified preparations of the histidine decarboxylase (specific activity 7-13 mumol X mg-1 X h-1). Further, no incorporation of 32P from AT32P during incubation of this enzyme with the protein kinase could be demonstrated. Therefore, if protein phosphorylation operates in the regulation of the histidine decarboxylase, factors removed during the purification must be involved.

Animals↗

PubMed2005

pH-dependent redox and CO binding properties of chelated protoheme-L-histidine and protoheme-glycyl-L-histidine complexes.

The pH dependence of redox properties, spectroscopic features and CO binding kinetics for the chelated protohemin-6(7)-L-histidine methyl ester (heme-H) and the chelated protohemin-6(7)-glycyl-L-histidine methyl ester (heme-GH) systems has been investigated between pH 2.0 and 12.0. The two heme systems appear to be modulated by four protonating groups, tentatively identified as coordinated H(2)O, one of heme's propionates, N(epsilon) of the coordinating imidazole, and the carboxylate of the histidine residue upon hydrolysis of the methyl ester group (in acid medium). The pK (a) values are different for the two hemes, thus reflecting structural differences. In particular, the different strain at the Fe-N(epsilon) bond, related to the different length of the coordinating arm, results in a dramatic alteration of the bond strength, which is much smaller in heme-H than in heme-GH. It leads to a variation in the variation of the pKa for the protonation of the N(epsilon) of the axial imidazole as well as in the proton-linked behavior of the other protonating groups, envisaging a cross-talk communication mechanism among different groups of the heme, which can be operative and relevant also in the presence of the protein matrix.

Carbon Monoxide↗

PubMed1985

Formation of N tau-ribosylhistidine, a novel histidine derivative found in the urine in histidinemia, from histidine and NAD(P)+ catalyzed by an NAD(P)+ glycohydrolase system.

The formation of N tau-ribosylhistidine (His-R), a novel histidine derivative found in the urine of histidinemic patients, was studied. A most possible synthetic pathway catalyzed by imidazole acetic acid (ImAA) phosphoribosyltransferase was not substantiated, because p.o. administration to humans and rats of aspirin, an inhibitor of the enzyme, did not change the urinary excretion of His-R, whereas aspirin decreased the excretion of ImAA-R with concomitant increase in that of ImAA. His-R was produced on incubation of a rat liver homogenate or its membrane fraction with histidine, NAD(P)+ and MgCl2, but not with only histidine or NAD(P)+. Nicotinamide inhibited the formation of His-R. Thus the enzymes responsible for the formation of His-R were suggested to be NAD(P)+ nucleosidase, nucleotide pyrophosphatase and 5'-nucleotidase.

5'-Nucleotidase↗

PubMed1991

Effects of cyanogen bromide modification of the distal histidine on the spectroscopic and ligand binding properties of myoglobin: magnetic circular dichroism spectroscopy as a probe of distal water ligation in ferric high-spin histidine-bound heme proteins.

Magnetic circular dichroism (MCD) spectroscopy has been utilized to characterize the change in coordination structure in native ferric sperm whale myoglobin upon cyanogen bromide-modification. Comparison of the MCD properties of the ferric high-spin state of cyanogen bromide-modified myoglobin (BrCN-Mb) with those of native ferric horseradish peroxidase and Aplysia myoglobin suggests that ferric BrCN-Mb is a potential MCD model for the pentacoordinate state of ferric high-spin histidine-ligated heme proteins. These five-coordinate heme proteins afford a relatively weak and unsymmetric signal in the Soret region of the MCD spectrum. In contrast, native ferric myoglobin and the benzohydroxamic acid adduct of ferric horseradish peroxidase show a strong and symmetric derivative-shaped Soret MCD signal which is indicative of hexacoordination with water and histidine axial ligands. Therefore it seems that MCD spectroscopy could be used to probe the presence of water ligated to the distal side of ferric high-spin heme proteins. The MCD spectra of the ferric-azide, ferrous-deoxy and ferrous-CO forms of BrCN-Mb have also been measured and compared to those of analogous native myoglobin complexes. The present MCD study has been extended to include new ligands, NO, thiocyanate and cyanate, which bind to ferric BrCN-Mb. With exogenous ligands such as CO, NO and thiocyanate, the coordination structures of the BrCN-Mb complexes are similar to those of the respective native myoglobin adducts. In the case of ferrous-deoxy and ferric-cyanate BrCN-Mb, however, the altered MCD spectra (and EPR for the latter) reveal changes in electronic structure which likely correlate with alterations of the coordination environment of these BrCN-Mb derivatives. Data are also presented which support the proposed tetrazole-bound structure for azide-treated BrCN-Mb (Hori, H., Fujii, M., Shiro, Y., Iizuka, T., Adachi, S. and Morishima, I. (1989) J. Biol. Chem. 264, 5715-5719) and the inability of the distal histidine of BrCN-Mb to stabilize the ferric ligand-bound state.

Animals↗

PubMed2006

Chiral resolution of histidine using an anti-D-histidine L-RNA aptamer microbore column.

In this paper, we report a new anti-amino acid aptamer chiral stationary phase (CSP). The enantiomers of histidine were separated using an immobilized histidine-specific L-RNA aptamer (40-mer) and an aqueous buffer as mobile phase. The effects of the variation of different operating parameters, including the mobile phase pH and the MgCl2 concentration as well as the column temperature, on the solute retention were assessed. The results suggested that (i) the protonated form of histidine was involved in the stereospecific RNA binding and (ii) Mg2+ was essential for the target enantiomer binding to the specific aptamer sites. From a practical point of view, it appeared that the baseline resolution in a minimum analysis time can be achieved at a column temperature of 35 degrees C for an eluent containing 10 mM of MgCl2, pH 5.5.

Aptamers, Nucleotide↗

PubMed2006

High-throughput screening for the asymmetric transformation reaction of L-histidine to D-histidine by capillary array electrophoresis.

Asymmetric transformation reaction of L-histidine to D-histidine was studied by homemade capillary array electrophoresis for the first time. The enantiomeric excess value of asymmetric histidine products can be directly determined from the electrophoretogram of capillary array electrophoresis. The experiment results showed that the optimized asymmetric transformation reaction condition was in the presence of salicylaldehyde as catalyst and acetic acid as solvent.

Aldehydes↗