Identification of the lysine and histidine transporter family in Camellia sinensis and the characterizations in nitrogen utilization

In plants,the lysine and histidine transporter(LHT)family represent a class of proteins that mediate the uptake,translocation,and utilization of amino acids.The tea plant(Camellia sinensis)is a perennial evergreen with a relatively high level of amino acids.However,systematic identification and molecular characterization of the LHT gene family has rarely been reported in tea plants.In this study,22 CsLHTs were identified from the‘Shuchazao’genome and classified into two groups.The modeled three-dimensional structure and the conserved domains presented a high similarity among the LHTs proteins.Moreover,it was predicted that a few genes were conserved through the analysis of the physiochemical characters,structures and cis-elements in promoters.The expression patterns in tea plants revealed that CsLHT7 was mainly expressed in the roots,and CsLHT4 and CsLHT11 exhibited relatively high expression in both the roots and leaves.Moreover,the expression of all three genes could be induced by organic nitrogen.Additionally,heterogeneous expression of CsLHT4,CsLHT7 and CsLHT11 in Arabidopsis thaliana decreased the aerial parts biomass compared with that in WT plants while significantly increased the rosette biomass only for CsLHT11transgenic plants versus WT plants.Overall,our results provide fundamental information about CsLHTs and potential genes in N utilization for further analysis in tea plants.

Bile acid increases expression of the histamine-producing enzyme,histidine decarboxylase,in gastric cells

AIM:To investigate the effect of bile acid on the expression of histidine decarboxylase(HDC),which is a major enzyme involved in histamine production,and gene expression of gastric transcription factors upon cooperative activation.METHODS:HDC expression was examined by immunohistochemistry,reverse transcriptase polymerase chain reaction,and promoter assay in human gastric precancerous tissues,normal stomach tissue,and gastric cancer cell lines.The relationship between gastric precancerous state and HDC expression induced by bile acid was determined.The association between the expression of HDC and various specific transcription factors in gastric cells was also evaluated.MKN45 and AGS human gastric carcinoma cell lines were transfected with farnesoid X receptor(FXR),small heterodimer partner(SHP),and caudal-type homeodomain transcription factor(CDX)1 expression plasmids.The effects of various transcription factors on HDC expression were monitored by luciferase-reporter promoter assay.RESULTS:Histamine production and secretion in the stomach play critical roles in gastric acid secretion and in the pathogenesis of gastric diseases.Here,we show that bile acid increased the expression of HDC,which is a rate-limiting enzyme of the histamine production pathway.FXR was found to be a primary regulatory transcription factor for bile acid-induced HDC expression.In addition,the transcription factors CDX1 and SHP synergistically enhanced bile acid-induced elevation of HDC gene expression.We confirmed similar expression patterns for HDC,CDX1,and SHP in patient tissues.CONCLUSION:HDC production in the stomach is associated with bile acid exposure and its related transcriptional regulation network of FXR,SHP,and CDX1.

Thermokinetics of Liquid-Liquid Reaction of Dy(NO_3)_3 with Histidine

The thermokinetics of liquid liquid reaction of dysprosium nitrate with histidine were studied using a microcalorimeter. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constant, three kinetic parameters (the activation energy, the pre exponential constant and the reaction order) were obtained. On the basis of thermodynamics and kinetics, the formation reaction of the complex was discussed.

Aberrant crypt focus and fragile histidine triad protein in sporadic colorectal carcinoma

AIM:To characterize aberrant crypt focus (ACF) in adjoining mucosa in sporadic colorectal carcinoma and to evaluate fragile histidine triad (Fhit) protein and Ki67. METHODS:ACF was identified grossly and classified histologically in 75 resected specimens. ACF was typed into hyperplastic ACF (HACF) and dysplastic ACF (DACF). Sections of ACF, carcinoma and normal colonic mucosa as control were studied for Fhit and Ki67 expressions by immunohistochemistry and were grouped according to staining intensity and the number of positive stained cells observed in different histological groups. Comparison was done between the different groups by Pearson's χ 2 test and γ test for the ordinal data. P value < 0.05 was considered as significant.RESULTS:Age range was 40 to 86 years in males (mean = 43.36) and 45 to 70 years in females (mean = 56). HACF was identified in all cases studied in the non-tumorous colonic mucosa; ACF was observed as non-contiguous scattered foci, which supports the hypothesis of acquisition of single focus monoclonality by colonic epithelial cells in tumor generation. Twenty-four (32%) had DACF and were observed as closure to carcinoma foci. Intensity of Fhit expression:(1) HACF 40% exhibited strong intensity, similar to normal, moderate in 36% and weak in 24%; (2) DACF strong in 25%, moderate in 37.5% and weak in 37.5%; and (3) carcinoma negative in 16%, strong in 43% and moderate and weak in 28.5% each. Significant difference was observed in intensity of the Fhit protein expressions by HACF and DACF (P < 0.05). Tumor in older patients showed a stronger Fhit intensity compared to younger patients (P = 0.036). Vegetarian diet intake and nonsmokers showed stronger Fhit intensities. Advanced stage tumor, non-vegetarian diet and younger age was associated with loss of Fhit protein. Ki67 positivity was an extended crypt pattern in HACF and DACF showed extension up to the neck region of the crypts and surface epithelium. Carcinomas showed a marked increase in Ki67 expression (P < 0.05). Fhit protein had an inverse association with Ki67 expression. CONCLUSION:Weaker Fhit intensity was associated with smoking, non-vegetarian diet intake and increasing Ki67 expression. Loss of Fhit protein expression is possibly influenced by environmental factors like smoking and non-vegetarian diet intake.

Examination of Correlation between Histidine and Cadmium Absorption by Eleagnus angustifolia L.,Vitisvinifera L.and Nerium oleander L.Using HPLC-MS and ICP-MS

In this study,HPLC-MS and ICP-MS methods wereused for the determination of histidine and cadmiumin Eleagnusangustifolia L.,Vitisvinifera L.and Nerium oleander L.leaves taken from industrial area including Gaziantep and Bursa cities.To histidine determination by HPLC-MS,flow rate of mobile phase,fragmentor potential,injection volume and column temperature were optimized as 0.2mL·min^(-1),70V,15μL and 20℃,respectively.For extraction of histidine from plants,distilled water was used by applying on 90℃and 30min.The concentrations(as mg·kg^(-1))of histidine were found to be in range of 8~22for Eleagnusangustifolia L.,10~33for Vitisvinifera L.and 6~11for Nerium oleander L.The concentrations of cadmium were found to be in ranges of 6~21μg·kg^(-1) for Vitisvinifera L.15~110μg·kg^(-1) for Eleagnusangustifolia L.and 63~218μg·kg^(-1) for Nerium oleander L.

Enthalpies of Solution of Complexes of Rare Earth Nitrate with L-α-Histidine in Water

The enthalpies of solution in water of complexes of RE(NO 3) 3 (RE=La～Nd, Sm～Lu, Y) with L α Histidine (His) were measured at 298.15 K. The standard enthalpies of formation of RE(His) 3+ (aq) were calculated. The 'tetrad effect' regularity was observed from the curve, which is the enthalpies of solution plotted against the atomic numbers of the elements in lanthanide series.

Crystal Structure of 2,6-Dihistidine Dimethyl Ester Pyridine Acylamine Monohydrate

The crystal structure of the title compound,C21H25N7O7,has been determined in the orthorhombic space group C222（1） with a=8.993（10）,b=12.149（14）,c=22.20（2）A and Z=4.There exist intramolecular C-H…O and N-H…N hydrogen bonds in the title crystal structure.The intermolecular N-H…N and C-H…O hydrogen bonds together with π-π stacking interactions（face-to-face） link the molecules into an infinite three-dimensional supramolecular network.

Urinary Concentrations of Hydroxyproline and 3-Methyl Histidine in Postpartum Cow

The urinary concentrations of hydroxyproline (HYPRO)and 3 -methyl histidine (3 - MEHIS) were de- termined in 16 Chinese-Holstein cows. The objectives of the experiment were to find out thhe relationship between collagen and myosin ddegradation and uterine involution in the postpartum cow. The results in the experiment showed that the mean concentrations of HYPRO and 3-MEHIS were 138.32±22.99 and 37.09 ±3.90 nmol·mL-1,respectively,for the cows during the days between 60-90 postpartum,and for the cows immediately after calving the concentrations of HYPRO and 3 -MEHIS reduced from 284.30 and 65.48 nmol ·mL-1 on the day one after calving to the normal level of 109.18 and 33.51 nmol·mL^-1 on the day 50 post- partum,respectively. There was a good correlation between the urinary concentrations of both HYPRO and 3 -MEHIS and the diameters of the involuting uterus (r = 0. 79).

Peripheral Concentration of Hydroxyproline and 3-methyl-histidine in Postpartum Cow

A total of 16 Friesian cows were used in the study to determine the peripheral concentration of hydroxyproline(HYPRO) and 3 methyl histidine(3 MEHIS).The objectives of the experiment were to find out the relationship between collagen and myosin degradation and uterine involution in the postpartum cow.The results showed tht the mean concentrations of HYPRO and 3 MEHIS were 13.47±2.38 and 18.35±2.77 n mole/mL,respectively,for the cows during the days 60～90 postpartum.And for the cows immediately after calving the concentrations of HYPRO and 3 HEHIS reduced from 34.29 and 28.06 nmole/mL on the day one after calving to the normal lever of 13.23 and 17.97 n mole on the day 50 postpartum,respectively.There was a good correlation between the peripheral concentrations of both HYPRO and 3 MEHIS and the diameters of the involuting uterus(r=0.8128).

Studies on the Interactions between Potassium oxalato-oxodiperoxovanadate and Histidine by NMR and MS

Multi-nuclear NMR and ESI-MS have been applied to study the interactions between oxalato-oxodiperoxovanadate and histidine in neutral solution. Coordination between the complex and histidine was monitored by V-51 NMR. A pair of new isomers produced via vanadium atom binding separately to N1 and N3 of the imidazole ring of histidine was characterized by several spectroscopic methods. Experimental results show that the structure activity relationship of peroxovanadium complexes bearing organic ligands may be related to the specific recognition between peroxovanadium and histidine residue of tyrosine phosphatase.

Identification of a sensor histidine kinase (BfcK) controlling biofilm formation in Clostridium acetobutylicum

Clostridium acetobutylicum has been extensively exploited to produce biofuels and solvents and its biofilm could dramatically improve the productivities.However,genetic control of C.acetobutylicum biofilm has not been dissected so far.Here,to identify potential genes controlling C.acetobutylicum biofilm formation,over 40 gene candidates associated with extracellular matrix,cell surface,cell signaling or gene transcription,were tried to be disrupted to examine their individual impact.A total of 25 disruptants were finally obtained over years of attempts,for which biofilm and relevant phenotypes were characterized.Most of these disruptants formed robust biofilm still,or suffered both growth and biofilm defect.Only a strain with a disrupted histidine kinase gene(CA_C2730,designated bfcK in this study)abolished biofilm formation without impairing cell growth or solvent production.Further analysis revealed that bfcK could control flagellar biogenesis and cell motility at protein levels.The bfcK also appeared to repress the phosphorylation of a serine/threonine protein kinase(encoded by CA_C0404)that might negatively regulate biofilm formation.Based on these findings,possible bfcK-mediated mechanisms for biofilm formation were proposed.This is a big step toward understanding the biofilm formation in C.acetobutylicum and will help further engineering of its biofilm-based industrial processes.

SYNTHESIS OF α-AMINO-β-(4-IMIDAZOLYL)-ETHYLPHOSPHONIC ACID,THE PHOSPHONOISOSTERE OF HISTIDINE

A short synthesis starting from 4-imidazolylmethanol(2)was developed for the phosphonoisostere of histidine,-amino-β-(4-imidazolyl)- ethylphosphosphonic acid,His(P)(1).The synthesis features Wittig-Horner reaction of aldehyde(4)with diphosphonate(5)followed by selective detritylation with 50% formic acid.

Cellulose Beads Modified by Histidine:Preparation and Adsorption Behavior

Porous cellulose beads modified by histidine (PCBH) were prepared. The adsorption capacity of PCBH for divalent Mg(II), Cu(II), Pb(II) and Hg(II) ions were determined. The effects of the temperature, the initial pH value, the concentration of metal ion and PCBH ligand on the adsorption of Cu(II) Hg (II) were discussed. The adsorption process fitted to Freundlich adsorption isotherms for both metal ions. Adsorption rate constants were also found.

EXPRESSION OF FRAGILE HISTIDINE TRIAD AND P53 IN NON-SMALL CELL LUNG CANCER

Objective： To investigate the expression offragile histidine triad （FHIT） and p53 protein in non-small cell lung cancer （NSCLC） and explore the relationship between their expressions and the clinicopathological features. Methods： FHIT protein and p53 protein were detected by immunohistochemistry in 76 cases of NSCLCs and matched normal lung tissues. Results： Fifty-one cases （67.1%） showed negative expression of FHIT （apparent reduction or loss） and thirty-seven cases （48.7%） showed p53 positive expression （overexpression）. The difference was significant （P=0.04）. However, there was no significant difference in FHIT expression between the p53-positive group and the p53-negative group （64.9% versus 69.2%, P=0.686）. The negative rate of FHIT protein expression was higher in squamous cell carcinoma than in adenocarcinoma, in moderately and poorly differentiated carcinoma than in well-differentiated carcinoma, and in cases with smoking history than in cases without smoking history （P〈0.05）. There was no relationship between FHIT expression and clinical stage or lymph node metastasis. The negative FHIT expression was not an independent predictor of overall survival （P=0.338）. Conclusion： The frequency of negative expression of FHIT protein is higher than that of positive expression of p53 in NSCLCs. The negative expression of FHIT is independent of the expression of p53. The change of expression of FHIT may play a role in the smoking related lung tumorigenesis while it may have no relationship with the progress of NSCLC or prognosis of the patients.

Flow Injection Analysis of Histidine with Enhanced Electrogenerated Chemiluminescence of Luminol

A simple and sensitive flow injection method is presented for the determination of histidine based on its enhancement of electrogenerated chemiluminescence (ECL) of luminol. After optimization of the experimental parameters, the working range for histidine was in 1.0 x 10-6 to 1.0 x 10 -3 mol/L with a detection limit (S/N = 3) of 0.56 mmol/L. The relative standard deviation was 1.6% for 11 measurements of 5 x 10 5 mol/L histidine solution. The proposed method has been successfully applied to the determination of histidine in real pharmaceutical preparation.

Crystal Structure and Specific Rotation of a Tetrakis－HistidineOcto－Aquo Di－Erbium Perchlorate Complex

The title complex [Er_2 (His·H￣+)_4 (H_2O)_8] (ClO_4)_(10)·4H_2O was synthesized in aqueous solution and its crystal structure was determined by X ray diffraction method. The crystal is triclinic, space group P1 with a=1.1726(2) nm, b=1.2660(3) nm, c=1.3142(3) nm, a=82. 92(3)°,β=70. 86(3)°, γ=83.06(3)°, V=1. 8223(7) nm￣3, Z=1, Dc=1.977g/cm￣3. The complex was a binuclear molecule, and each erbium ion is coordinated by four carboxylic oxygen atoms from four histidine and four oxygen atoms from H_2O, forming a coordination polyhedron of square antiprism. The structure analysis and specific rotation determination shows that the crystal contains enantiomers.

Histidine decarboxylase and urinary methylimidazoleacetic acid in gastric neuroendocrine cells and tumours

AIM: To study histidine decarboxylase(HDC) expression in normal and neoplastic gastric neuroendocrine cells in relationship to the main histamine metabolite. METHODS: Control tissues from fundus(n = 3) and corpus(n = 3) mucosa of six patients undergoing operations for gastric adenocarcinoma, biopsy and/or gastric surgical specimens from 64 patients with primary gastric neuroendocrine tumours(GNETs), as well as metastases from 22 of these patients, were investigated using conventional immunohistochemistry and double immunofluorescence with commercial antibodies vs vesicular monoamine transporter 2(VMAT-2), HDC and ghrelin. The urinary excretion of the main histamine metabolite methylimidazoleacetic acid(U-Me Im AA) was determined using highperformance liquid chromatography in 27 of the 64 patients.RESULTS: In the gastric mucosa of the control tissues, co-localization studies identified neuroendocrine cells that showed immunoreactivity only to VMAT-2 and others with reactivity only to HDC. A third cellpopulation co-expressed both antigens. There was no co-expression of HDC and ghrelin. Similar results were obtained in the foci of neuroendocrine cell hyperplasia associated with chronic atrophic gastritis type A and also in the tumours. The relative incidence of the three aforementioned markers varied in the tumours that were examined using conventional immunohistochemistry. All of these GNETs revealed both VMAT-2 and HDC immunoreactivity, and their metastases showed an immunohistochemical pattern and frequency similar to that of their primary tumours. In four patients, increased U-Me Im AA excretion was detected, but only two of the patients exhibited related endocrine symptoms. CONCLUSION: Human enterochromaffin-like cells appear to partially co-express VMAT-2 and HDC. Coexpression of VMAT-2 and HDC might be required for increased histamine production in patients with GNETs.

DETERM INATION OF THE STABILITY CONSTANTS OF COMPLEXES OF HISTIDINE,SOME DIPEPTIDES AND TRIGLYCINE WITH Zn(Ⅱ)AND Cd(Ⅱ)USING SMALL-SCALE PH-METRIC TITRATIONS

A potentiometric study on the complexes of His,Gly-His,ALa-His,Gly-Gly and Gly—Gly—Gly with Zn(Ⅱ)and Cd(Ⅱ)has been reported.Small-scale potentiometric titrations were car- ried out to determine stabil ity constants of complexes at 25℃ with I=0.10 mol dm^(-3)(KNO_3).The com- puter programs SUPERQUAD were applied for data treatment with satisfactory results.

The Hydrolysis of RNA by Histidine

The cleavage activity of histidine on RNA and DNA was tested. It was found that histidine could cleave RNA, but not DNA The cleavage mechanism was proposed to be involved in the hydrolysis of the phosphodiester backbone.

RNA Cleavage by N-Phosphoryl Serine in Histidine Buffer

In the presence of histidine, N-(O,O-diisopropyl)phosphoryl serine could catalyze the cleavage of RNA in aqueous solution at neutral pH. The results were detected by sub-marine agarose gel electrophoresis and capillary zone electrophoresis. It was found that at high concentration histidine could cleave the RNA slightly. While the participation of DIPP-Ser could significantly accelerate the cleavage reaction. N-phosphodipeptide---N-(O,O-diisopropyl) Ser-His are proposed to be involved in the mechanism.