• Title/Summary/Keyword: zinc-binding ligands

Search Result 8, Processing Time 0.021 seconds

Identifiaction and Molecular Size of Zine-Binding Ligands in Pancreatic/Biliary Fluid of Rats

  • Kwun, In-Sook;Donald Oberleas
    • Preventive Nutrition and Food Science
    • /
    • v.2 no.1
    • /
    • pp.42-48
    • /
    • 1997
  • the exocrine pancreatic secretion is an important factor in the maintenance of zinc homeostasis. The daily pancreatic secretion of zinc into the gastrointestinal tract may be two or more times the daily dietary zinc intake. The objective of this study was to examine the distribution of proteins and zinc in pancreatic/biliary fluid following intraperitoneal {TEX}${65}^Zn${/TEX} injection into dietary prepared Sprague-Dawly rats. Distribution of zinc-binding protein in Sephadex G-75 subfractions showed a peak corresponding to the high molecular weight protein standard(<66kDa) in the pancreatic/biliary fluid. Zinc also was associated with the 29~35kDa mole-cular weight proteins. These are similar in size with zinc-containing enzymes, carboxypeptidase A and car-boxypeptidase B. A more remarkable small molecular weight fraction eluted beyond the 6.5kDa standard pro-tein peak. These results show the presence of small molecular weight compound in pancreatic/biliary fluid associated with zinc . These small molecular weight compounds may serve as zinc-binding ligands for the secretion of enogenous zinc into the duodenum. These findings suggest that these lignads may dissociate zinc in the duodenum thus making it vulnerable to complexation with phytate in the upper gastrointestinal tract rendering the zinc unavailable for reabsorption.

  • PDF

Molecular Size and Distribution of Zinc-binding Ligands in Rat Pancreatic Tissue

  • Kwun, In-Sook;Donald Oberleas
    • Preventive Nutrition and Food Science
    • /
    • v.2 no.3
    • /
    • pp.219-224
    • /
    • 1997
  • The pancreas is an important organ in the maintenance of zine homeostasis. The pancreatic tissue used in this study was obtained from rats fed varying levels of dietary Ca nd phytate followed by intraperitoneal {TEX}${65}^Zn${/TEX} injection. THe objective of this study was to determine the molecular size and distribution of compounds that may represent zinc-binding complexes in pancreatic tissue homogenates. The supernatant of the homogenized pancreatic tissue was separated using a Sephadex G-75 column with Tris buffer at pH 8.1. All subfractions were assayed for zinc, protein and {TEX}${65}^Zn${/TEX} activity. The elution of subfractions from pancreatic tissue homogenates showed a prominent peak corresponding to the high molecular weight protein standard (>66kd). A sall molecular weigth protein (<6.5kd), that was absorbed at 280nm, was also present: prominently in low Ca group, however not much as in high Ca group. These small compounds may combine weakly with zinc in pancreatic tissue an serve as zinc-binding ligands in pancreatic/biliary fluid. In the duodenum, these ligands dissociate zinc into an ionic form which becomes vulnerable to phytate complexation.

  • PDF

Antibacterial and Antifungal Studies on Some Schiff Base Complexes of Zinc(II)

  • Joseyphus, R. Selwin;Nair, M. Sivasankaran
    • Mycobiology
    • /
    • v.36 no.2
    • /
    • pp.93-98
    • /
    • 2008
  • Two Schiff base ligands $L_1\;and\;L_2$ were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1:1 electrolytes. The IR data demonstrate the tetradentate binding of $L_1$ and tridentate binding of $L_2$. The XRD data show that Zn(II) complexes with $L_1\;and\;L_2$ have the crystallite sizes of 53 and 61 nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.

Virtual screening, molecular docking studies and DFT calculations on JNK3

  • Priya, dharshini;Thirumurthy, Madhavan
    • Journal of Integrative Natural Science
    • /
    • v.15 no.4
    • /
    • pp.179-186
    • /
    • 2022
  • The c-Jun N-terminal kinase (JNK3) play major role in neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, cerebral ischemia and other Central Nervous System disorders. Since JNK3 is primarily stated in the brain and stimulated by stress-stimuli, this situation is conceivable that inhibiting JNK3 could be a possible treatment for the mechanisms underlying neurodegenerative diseases. In this study drugs from Zinc15 database were screened to identify the JNK3 inhibitors by Molecular docking and Density functional theory approach. Molecular docking was done by Autodock vina and the ligands were selected based on the binding affinity. Our results identified top ten novel ligands as potential inhibitors against JNK3. Molecular docking revealed that Venetoclax, Fosaprepitant and Avapritinib exhibited better binding affinity and interacting with proposed binding site residues of JNK3. Density functional theory was used to compute the values for energy gap, lowest unoccupied molecular orbital (LUMO), and highest occupied molecular orbital (HOMO). The results of Density functional theory study showed that Venetoclax, Fosaprepitant and Avapritinib serves as a lead compound for the development of JNK3 small molecule inhibitors.

Accumulation and Elimination of Cadmium and Zinc in Littorina brevicula (총알고둥에서 카드뮴과 아연의 축적과 제거)

  • Han, Su-Jeong;Lee, In-Suk
    • The Korean Journal of Ecology
    • /
    • v.24 no.1
    • /
    • pp.35-43
    • /
    • 2001
  • Accumulation, elimination and subcellular distribution of heavy metals in Littorina brevicula exposed to cadmium and zinc separately and concurrently were investigated. When the winkles had been exposed to 400 ㎍/L CdCl₂ and 3000 ㎍/l ZnSO₄ separately for 90 days, each of the metal body burden in the whole sofl parts increased in proportion to time of exposure until 70 days. But it didn't increase after 70 days. But when the winkles had been exposed to cadmium and zinc simultaneously, cadmium body burden decreased but zinc body burden increased as compared to the winkles exposed to each of the metal. We also found that cadmium accumulated in the winkles was not depurated for 42 days, but zinc accumulated in them was depurated. Especially, zinc was depurated faster when they had been exposed to mixture of cadmium and zinc. After the winkles had been exposed to cadmium and zinc separately for 70 days, about 60% cadmium of the total body burden was associated with the soluble fraction, while about 75% zinc of the total body burden was associated with insoluble fraction. And these trends of metal partitioning did not alter when the winkles had been exposed to metal mixture. After the soluble fraction applied to gel-filtration chromatography column, the distribution patterns of cadmium and zinc associated with proteins or ligands were different each other. Most of cadmium (>90%) in the soluble fraction was bound to MBP-1 (Metal-binding protein-1), about 6.5 kDa), while zinc was distributed evenly to HMW (High molecular weight fraction, >60 kDa), MBP-1, MBP-2 (about 5 kDa), LMW (Low molecular weight fraction, <1 kDa).

  • PDF

Molecular Characterization and Expression of CuZn-superoxide Dismutase (PSOD1) from Populus alba${\times}$Populus glandulosa

  • Lee Jun-Won;In Jun-Gyo;Lee Bum-Soo;Choi Yong-Eui;Kim Jin-Ju;Yang Deok-Chun
    • Plant Resources
    • /
    • v.8 no.1
    • /
    • pp.52-59
    • /
    • 2005
  • A cDNA, PSOD1, encoding cytosolic copper/zinc superoxide dismutase (CuZn-SOD) was cloned and characterized from a full length cDNA library prepared from Populus alba${\times}$Populus glandulosa cultured in vitro. A PSOD1, is 725 nucleotides long and has an open reading frame of 459 bp with 152 amino acid residues (pI 5.43). The deduced amino acid sequence of PSOD1 perfect matched to the previously reported CuZn-SOD (CAC33845.1). Consensus amino acid residues (His-45, -47, -62, -70, -79, -119) were involved in Cu-, Cu/Zn-, and Zn- binding ligands. The deduced amino acid sequence of PSOD1 exhibited the high level of similarity from 100 to $85\%$ among previously registered SOD genes. The expression of PSOD1 in poplar increased at the 1 mM $H_{2}O_2$ and drought stress during 30 min and 60 min, but the ozone treated poplar increased at 30 min in the early time and then decreased at 60 min.

  • PDF

Characterization of Copper/Zinc-Superoxide Dismutase (Cu/Zn-SOD) Gene from an Endangered Freshwater Fish Species Hemibarbus mylodon (Teleostei; Cypriniformes)

  • Lee, Sang-Yoon;Kim, Keun-Yong;Bang, In-Chul;Nam, Yoon-Kwon
    • Fisheries and Aquatic Sciences
    • /
    • v.14 no.1
    • /
    • pp.43-54
    • /
    • 2011
  • Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.