Plant Peptidoglucans Affecting the Phenotypic Expression of Rhizobial Nitrogenase

1980 ◽  
Vol 7 (3) ◽  
pp. 251 ◽  
Author(s):  
R Storey ◽  
M Reporter
Keyword(s):  
Nitrogenase Activity ◽  
Phenotypic Expression ◽  
Deae Cellulose ◽  
H2 Production ◽  
Rhizobium Japonicum ◽  
Small Peptide ◽  
Root Cells ◽  
Rhizobium Strains ◽  
Hydrolysis Of

Dialysable substances capable of influencing rhizobial nitrogenase activity in vitro were obtained from Glycine max root cells during transfilter coculture with Rhizobium japonicum. These substances from the liquid plant-conditioned medium were chromatographed on Sephadex G-25, DEAE- cellulose and carboxymethylcellulose and on a concanavalin A-Sepharose column. The separated active column fractions initiated the phenotypic expression of nitrogenase activity (C2H2 reduction, H2 production) in different Rhizobium strains. Hydrolysis of these column fractions showed them to contain a small peptide and a glucan. Analysis of active fractions also showed the presence of bound copper. It was concluded that the plant fractions involved in stimulating rhizobial nitrogenase activity were peptidoglucans; at least one active fraction may also be a copper metallothionein.

In vitro nitrogenase activity of Rhizobium japonicum affected by conditioned medium from cultured plant cells

1979 ◽  
Vol 14 (3) ◽  
pp. 253-258 ◽  
Author(s):  
Richard Storey ◽  
Kathy Rainey ◽  
Leslie Pope ◽  
Minocher Reporter
Keyword(s):  
Conditioned Medium ◽  
Nitrogenase Activity ◽  
Plant Cells ◽  
Rhizobium Japonicum

scholarly journals Role of Plant Cell Conditioned Medium in the Phenotypic Expression of Nitrogenase Activity of Rhizobium trifolii Strain T1

1980 ◽  
Vol 33 (5) ◽  
pp. 613 ◽  
Author(s):  
Minocher Reporter ◽  
Mary L Skotnicki ◽  
Barry G Rolfe
Keyword(s):  
Oxidative Phosphorylation ◽  
Conditioned Medium ◽  
Plant Cell ◽  
Nitrogenase Activity ◽  
Phenotypic Expression ◽  
Atp Synthesis ◽  
Atp Production ◽  
Cell Conditioned Medium

The influence of substances from a conditioned medium of cultured plant cells on nitrogenase activity, respiration and ATP synthesis was investigated in R. tri/olii strain Tl. Nitrogenase activity in strain Tl was dependent on the addition of the plant cell conditioned medium. Studies showed that the initial effects of the plant substances on rhizobial cells was to increase their respiration rate and ATP production. Mutants of strain Tl which were uncoupled in their oxidative phosphorylation, were also tested. However, the plant factors had no effect on respiration and ATP synthesis and also failed to elicit in vitro nitrogenase activity in these mutants. It is proposed that these plant factors act by increasing the efficiency of oxidative phosphorylation, making more ATP available, and thus stimulating nitrogenase activity of R. tri/olii cells.

Total Synthesis and Antibacterial Screening of (±)-6,8-Dihydroxy-3- undecyl-3,4-dihydroisochromen-1-one: A Structural Analogue of Metabolites from Ononis natrix

2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Structural Analog ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Antibacterial Screening ◽  
Maximum Inhibition ◽  
Bacillus Subtilus ◽  
Hydrolysis Of ◽  
Direct Condensation

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.

Studies on the mechanism of acute inhibition of thyroglobulin hydrolysis by iodine

1985 ◽  
Vol 108 (4) ◽  
pp. 511-517 ◽  
Author(s):  
Nandalal Bagchi ◽  
Birdie Shivers ◽  
Thomas R. Brown
Keyword(s):  
Time Course ◽  
Period 2 ◽  
Iodotyrosine Deiodinase ◽  
Rate Of Hydrolysis ◽  
Underlying Mechanisms ◽  
Excess Iodide ◽  
Sites Of Action ◽  
Hydrolysis Of

Abstract. Iodine in excess is known to acutely inhibit thyroidal secretion. In the present study we have characterized the time course of the iodine effect in vitro and investigated the underlying mechanisms. Labelled thyroid glands were cultured in vitro in medium containing mononitrotyrosine, an inhibitor of iodotyrosine deiodinase. The rate of hydrolysis of labelled thyroglobulin was measured as the proportion of labelled iodotyrosines and iodothyronines recovered at the end of culture and was used as an index of thyroidal secretion. Thyrotrophin (TSH) administered in vivo acutely stimulated the rate of thyroglobulin hydrolysis. Addition of Nal to the culture medium acutely inhibited both basal and TSH-stimulated thyroglobulin hydrolysis. The effect of iodide was demonstrable after 2 h, maximal after 6 h and was not reversible upon removal of iodide. Iodide abolished the dibutyryl cAMP induced stimulation of thyroglobulin hydrolysis. Iodide required organic binding of iodine for its effect but new protein or RNA synthesis was not necessary. The inhibitory effects of iodide and lysosomotrophic agents such as NH4C1 and chloroquin on thyroglobulin hydrolysis were additive suggesting different sites of action. Iodide added in vitro altered the distribution of label in prelabelled thyroglobulin in a way that suggested increased coupling in the thyroglobulin molecule. These data indicate that 1) the iodide effect occurs progressively over a 6 h period, 2) continued presence of iodide is not necessary once the inhibition is established, 3) iodide exerts its action primarily at a post cAMP, prelysosomal site and 4) the effect requires organic binding of iodine, but not new RNA or protein synthesis. Our data are consistent with the hypothesis that excess iodide acutely inhibits thyroglobulin hydrolysis by increasing the resistance of thyroglobulin to proteolytic degradation through increased iodination and coupling.

Nephrotoxicity Testing In Vitro: The Current Situation

1997 ◽  
Vol 25 (5) ◽  
pp. 497-503
Author(s):  
Jean-Paul Morin ◽  
Marc E. De Broe ◽  
Walter Pfaller ◽  
Gabriele Schmuck
Keyword(s):  
Proximal Tubule ◽  
Culture Media ◽  
Task Force ◽  
Primary Cultures ◽  
Phenotypic Expression ◽  
Transepithelial Transport ◽  
Specific Cell ◽  
Proximal Tubule Cells ◽  
Tubule Cells

An ECVAM task force on nephrotoxicity has been established to advise, in particular, on the follow-up to recommendations made in the ECVAM workshop report on nephrotoxicity testing in vitro. Since this workshop was held, in 1994, there have been several improvements in the techniques used. For example, the duration of renal slice viability, and the maintenance of functional activities in slices, have been improved by using dynamic incubation systems with higher oxygen tensions and more-appropriate cell culture media. Highly differentiated primary cultures of pig, human and rabbit proximal tubule cells have been established by using specific cell isolation procedures and/or selective culture media. To date, the most comparable phenotypic expression and transepithelial transport capacities to proximal tubules in vivo have been obtained with primary cultures of rabbit proximal tubule cells which are grown on bicompartmental supports; in this system, transepithelial substrate gradients are generated and the transepithelial transport of both organic anions and cations is highly active. This in vitro system has been selected by ECVAM for further evaluation and prevalidation. Industrial needs in the area of nephrotoxicity testing have been identified, and recommendations are made at the end of this report concerning possible future initiatives.

scholarly journals PenA, a penicillin-binding protein-type thioesterase specialized for small peptide cyclization

2021 ◽  
Author(s):  
Kenichi Matsuda ◽  
Kei Fujita ◽  
Toshiyuki Wakimoto
Keyword(s):  
Enzymatic Activity ◽  
Computational Model ◽  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Small Peptide ◽  
Peptide Cyclization ◽  
Chain Lengths ◽  
Non Ribosomal Peptides

Abstract Penicillin binding protein-type thioesterases (PBP-type TEs) are a recently identified group of peptide cyclases that catalyze head-to-tail macrolactamization of non-ribosomal peptides. PenA, a new member of this group, is involved in the biosyntheses of cyclic pentapeptides. In this study, we demonstrated the enzymatic activity of PenA in vitro, and analyzed its substrate scope with a series of synthetic substrates. A comparison of the reaction profiles between PenA and SurE, a representative PBP-type TE, showed that PenA is more specialized for small peptide cyclization. A computational model provided a possible structural rationale for the altered specificity for substrate chain lengths.

scholarly journals Antimicrobial Activity of Chitosan Oligosaccharides with Special Attention to Antiparasitic Potential

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 110
Author(s):  
Nayara Sousa da Silva ◽  
Nathália Kelly Araújo ◽  
Alessandra Daniele-Silva ◽  
Johny Wysllas de Freitas Oliveira ◽  
Júlia Maria de Medeiros ◽  
...  
Keyword(s):  
Disease Outbreaks ◽  
Biological Properties ◽  
Enzymatic Production ◽  
Infectious Disease Outbreaks ◽  
Chitosan Oligosaccharides ◽  
Lower Viscosity ◽  
Biomedical Industry ◽  
Parasite Aggregation ◽  
Hydrolysis Of

The global rise of infectious disease outbreaks and the progression of microbial resistance reinforce the importance of researching new biomolecules. Obtained from the hydrolysis of chitosan, chitooligosaccharides (COSs) have demonstrated several biological properties, including antimicrobial, and greater advantage over chitosan due to their higher solubility and lower viscosity. Despite the evidence of the biotechnological potential of COSs, their effects on trypanosomatids are still scarce. The objectives of this study were the enzymatic production, characterization, and in vitro evaluation of the cytotoxic, antibacterial, antifungal, and antiparasitic effects of COSs. NMR and mass spectrometry analyses indicated the presence of a mixture with 81% deacetylated COS and acetylated hexamers. COSs demonstrated no evidence of cytotoxicity upon 2 mg/mL. In addition, COSs showed interesting activity against bacteria and yeasts and a time-dependent parasitic inhibition. Scanning electron microscopy images indicated a parasite aggregation ability of COSs. Thus, the broad biological effect of COSs makes them a promising molecule for the biomedical industry.

scholarly journals Synthesis, Structure and In Vitro Anticancer Activity of Pd(II) Complex of Pyrazolyl-s-Triazine Ligand; A New Example of Metal-Mediated Hydrolysis of s-Triazine Pincer Ligand

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 119
Author(s):  
Jamal Lasri ◽  
Matti Haukka ◽  
Hessa H. Al-Rasheed ◽  
Nael Abutaha ◽  
Ayman El-Faham ◽  
...  
Keyword(s):  
Thermal Conditions ◽  
Molar Ratio ◽  
Chloride Salt ◽  
Pincer Ligand ◽  
Hydrogen Bonding Interactions ◽  
Square Planar ◽  
Hirshfeld Analysis ◽  
Hydrolysis Of ◽  
Mcf 7

The square planar complex [Pd(PT)Cl(H2O)]*H2O (HPT: 6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4(1H,3H)-dione) was obtained by the reaction of 2-methoxy-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine (MBPT) pincer ligand with PdCl2 in a molar ratio (1:1) under thermal conditions and using acetone as a solvent. The reaction proceeded via C-N cleavage of one C-N moiety that connects the pyrazole and s-triazine combined with the hydrolysis of the O-CH3 group. The reaction of the chloride salt of its higher congener (PtCl2) gave [Pt(3,5-dimethyl-1H-pyrazole)2Cl2]. The crystal structure of [Pd(PT)Cl(H2O)]*H2O complex is stabilized by inter- and intra-molecular hydrogen bonding interactions. Hirshfeld analysis revealed that the H...H (34.6%), O...H (23.6%), and Cl...H (7.8%) interactions are the major contacts in the crystal. The charges at Pd, H2O, Cl and PT are changed to 0.4995, 0.2216, −0.4294 and −0.2917 instead of +2, 0, −1 and −1, respectively, using the MPW1PW91 method. [Pd(PT)Cl(H2O)]*H2O complex has almost equal activities against MDA-MB-231 and MCF-7 cell lines with IC50 of 38.3 µg/mL.

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