Enhancing the T R Transition of Insulin by Helix-Promoting Sequence Modifications at the N-Terminal B-Chain

2000 ◽  
Vol 381 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Jewad Shneine ◽  
Marc Voswinkel ◽  
Matthias Federwisch ◽  
Axel Wollmer
Keyword(s):  
Phenolic Compounds ◽  
Metal Ions ◽  
Inorganic Anions ◽  
Phenol Concentration ◽  
Stoichiometric Ratio ◽  
Wild Type ◽  
Full Transformation ◽  
Chain Sequence ◽  
The Subject

Abstract Structurally, the T→R transition of insulin mainly consists of a rearrangement of the N-terminal B-chain (residues B1–B8) from extended to helical in one or both of the trimers of the hexamer. The dependence of the transition on the nature of the ligands inducing it, such as inorganic anions or phenolic compounds, as well as of the metal ions complexing the hexamer, has been the subject of extensive investigations. This study explores the effect of helix-enhancing modifications of the N-terminal B-chain sequence where the transition actually occurs, with special emphasis on N-capping. In total 15 different analogues were prepared by semisynthesis. 80% of the hexamers of the most successful analogues with zinc were found to adopt the T3R3 state in the absence of any transforming ligands, as compared to only 4% of wild-type insulin. Transformation with SCN− ions can exceed the T3R3 state where it stops in the case of wild-type insulin. Full transformation to the R6 state can be achieved by only one-tenth the phenol concentration required for wild-type insulin, i. e. almost at the stoichiometric ratio of 6 phenols per hexamer.

Synthesis of N2, N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide fluoroscent sensor for detection of Cu2+ and Ni2+ Ions

Drug Research ◽  
2021 ◽  
Author(s):  
Anuroop Kumar ◽  
Netrapal Singh ◽  
Mordhwaj Kumar ◽  
Uma Agarwal
Keyword(s):  
Spectral Analysis ◽  
Detection Limit ◽  
Metal Ions ◽  
1H Nmr Spectroscopy ◽  
Stoichiometric Ratio ◽  
Selective Detection ◽  
Ft Ir ◽  
Uv Visible ◽  
Complexes With Metal Ions ◽  
Competitive Ions

AbstractThis article reports an amide based Chemosensor used for selective detection of divalent Cu+2 and Ni+2 ions via Fluorescence turn off. The selective sensing ability of Chemosensor was investigated in presence of different metal ions Mg2+, Ag+, Fe2+, K+, Cu2+, Ni2+, Hg2+, Pb2+, Mn2+, Pd2+, Cd2+ and Mn3+ as competitive ions. The receptor i. e. Chemosensor formed complexes with metal ions in 1:1 stoichiometric ratio. The detection limit and binding constant calculated as 1.92×10–4 and 1.4×10–4 M and 2.16×103 M−1 and 3.09×103 M−1 for Cu2+ and Ni2+ions respectively. The complexes were characterized by UV/visible, FT-IR, 13C NMR and 1H NMR spectroscopy. Further the structure and Crystallinity were calculated by P-XRD spectral analysis. The crystallinity found to be 65.27 and 67.87% respectively

scholarly journals Carotenoid-Chlorophyll Interactions in a Photosynthetic Antenna Protein: A Supramolecular QM/MM Approach

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2589 ◽  
Author(s):  
Matthew Guberman-Pfeffer ◽  
José Gascón
Keyword(s):  
Chlorophyll A ◽  
Protein A ◽  
Transition Dipole Moment ◽  
Protein Domain ◽  
Electronic Coupling ◽  
Stoichiometric Ratio ◽  
Wild Type ◽  
Transition Dipole ◽  
Energy Capture ◽  
Photosynthetic Antenna

Multichromophoric interactions control the initial events of energy capture and transfer in the light harvesting peridinin-chlorophyll a protein (PCP) from marine algae dinoflagellates. Due to the van der Waals association of the carotenoid peridinin (Per) with chlorophyll a in a unique 4:1 stoichiometric ratio, supramolecular quantum mechanical/molecular mechanical (QM/MM) calculations are essential to accurately describe structure, spectroscopy, and electronic coupling. We show that, by enabling inter-chromophore electronic coupling, substantial effects arise in the nature of the transition dipole moment and the absorption spectrum. We further hypothesize that inter-protein domain Per-Per interactions are not negligible, and are needed to explain the experimental reconstruction features of the spectrum in wild-type PCP.

Simultaneous determination of inorganic anions and metal ions by suppressed ion chromatography

1999 ◽  
Vol 382 (3) ◽  
pp. 291-299 ◽  
Author(s):  
Maria Concetta Bruzzoniti ◽  
Edoardo Mentasti ◽  
Corrado Sarzanini
Keyword(s):  
Metal Ions ◽  
Simultaneous Determination ◽  
Ion Chromatography ◽  
Inorganic Anions

Coordination of Pentacyclohexanocucurbit[5]uril with Alkali Metal Ions and Supramolecular Self-Assembly in the Absence and Presence of Inorganic Anions

2013 ◽  
Vol 2013 (21) ◽  
pp. 3632-3640 ◽  
Author(s):  
Jing-Xu Hu ◽  
Ying-Feng Hu ◽  
Xin Xiao ◽  
Yun-Qian Zhang ◽  
Zhu Tao ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Metal Ions ◽  
Self Assembly ◽  
Inorganic Anions ◽  
Alkali Metal Ions

The morphology and development of Drosophila eye

Development ◽  
1967 ◽  
Vol 17 (3) ◽  
pp. 491-499
Author(s):  
E. W. Hanly ◽  
C. William Fuller ◽  
M. S. Millam Stanley
Keyword(s):  
Drosophila Melanogaster ◽  
Metabolic Pathways ◽  
Biosynthetic Pathways ◽  
Wild Type ◽  
Specific Enzyme ◽  
Type D ◽  
Red Color ◽  
Drosophila Eye ◽  
The Subject

The development of pigment in the eye of Drosophila melanogaster and other insects has been the subject of many studies and much controversy. It has been established that the red color of eyes of wild-type D. melanogaster is due to the presence of two classes of pigments, ommochromes and pteridines (Ziegler, 1961). The relationships among the various members of each class are still obscure; the biosynthetic pathways are yet to be elucidated. No specific enzyme involved in the synthesis of any member of either group has been isolated or characterized. It has been suggested, however (Hadorn, 1955), that these metabolic pathways may involve several organs, including the eye, but that the final deposition and conversion occur only in the eye. The recent development of a satisfactory technique for the culture of Drosophila organs (Schneider, 1964) has made possible the study of pigment development in the isolated eye and in eyes associated with selected organs.

Advances in understanding the nutritional value of antioxidants in wheat

2021 ◽  
pp. 29-72
Author(s):  
Franklin Brian Apea-Bah ◽  
◽  
Trust Beta ◽  
Keyword(s):  
Heavy Metal ◽  
Free Radicals ◽  
Phenolic Compounds ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Environmental Pollutants ◽  
Physiological System ◽  
Antioxidant Protection ◽  
Oxidation Reactions ◽  
Oxidant Effect

Whole grain wheat has a diverse supply of hydrophilic and lipophilic antioxidants which include phenolic compounds (phenolic acids, flavonoids, anthocyanins which are present only in pigmented wheat, alkylresorcinols, and to a lesser extent proanthocyanidins), carotenoids (mainly lutein and zeaxanthin) and tocochromanols (α, β, γ and δ - tocopherols and tocotrienols). This diversity of antioxidants function to protect consumers from radical-induced oxidative damage caused by various free radicals produced endogenously from metabolic processes and exogenously from sunlight and other chemicals and environmental pollutants. They also chelate metal ions which could catalyze oxidation reactions in the physiological system, thereby providing antioxidant protection. However, phenolic compounds might exert pro-oxidant effect when bound to heavy metal ions. This effect could be prevented by the diverse antioxidant system in wheat.

scholarly journals Sheathless Mutant of Cyanobacterium Gloeothece sp. Strain PCC 6909 with Increased Capacity To Remove Copper Ions from Aqueous Solutions

2008 ◽  
Vol 74 (9) ◽  
pp. 2797-2804 ◽  
Author(s):  
Ernesto Micheletti ◽  
Sara Pereira ◽  
Francesca Mannelli ◽  
Pedro Moradas-Ferreira ◽  
Paula Tamagnini ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Functional Groups ◽  
Metal Removal ◽  
Copper Ions ◽  
Dry Weight ◽  
Copper Binding ◽  
Wild Type ◽  
Removal Capacity ◽  
Acidic Sugars

ABSTRACT The cyanobacterium Gloeothece sp. strain PCC 6909 and its sheathless mutant were tested for their abilities to remove copper ions from aqueous solutions, with the aim of defining the role of the various outermost polysaccharidic investments in the removal of the metal ions. Microscopy studies and chemical analyses revealed that, although the mutant does not possess a sheath, it releases large amounts of polysaccharidic material (released exocellular polysaccharides [RPS]) into the culture medium. The RPS of the wild type and the mutant are composed of the same 11 sugars, although they are present in different amounts, and the RPS of the mutant possesses a larger amount of acidic sugars and a smaller amount of deoxysugars than the wild type. Unexpectedly, whole cultures of the mutant were more effective in the removal of the heavy metal than the wild type (46.3 ± 3.1 and 26.7 ± 1.5 mg of Cu2+ removed per g of dry weight, respectively). Moreover, we demonstrated that the contribution of the sheath to the metal-removal capacity of the wild type is scarce and that the RPS of the mutant is more efficient in removing copper. This suggests that the metal ions are preferably bound to the cell wall and to RPS functional groups rather than to the sheath. Therefore, the increased copper binding efficiency observed with the sheathless mutant can be attributed to the release of a polysaccharide containing larger amounts and/or more accessible functional groups (e.g., carboxyl and amide groups).

scholarly journals Photophysical Investigation of A Benzimidazole Derivative and Its Applications In Selective Detection of Fe3+, Thermosensing and Logic gates.

2021 ◽  
Author(s):  
Aishwarya Nadgir ◽  
Ashok H Sidarai
Keyword(s):  
Metal Ions ◽  
Logic Gate ◽  
Benzimidazole Derivative ◽  
Average Particle Size ◽  
Logic Gates ◽  
Relative Sensitivity ◽  
Average Particle ◽  
Stoichiometric Ratio ◽  
Potential Candidate ◽  
Ion Temperature

Abstract The fluorescence based applications such as chemosensing of Fe3+ ion, temperature sensing, NOR-gate molecular logic operations, and fluorescent ink were achieved using an expired medicine namely Pantoprazole (sensor1) which is a derivative of benzimidazole class. The phenomenon of quenching was a basic principle used in sensing Fe3+. We found that there was a combined effect of dynamic and static processes in quenching of fluorescence of sensor1. To confirm the selectiveness of sensor1, we performed interference experiments with other metal ions. There was no interference between these metal ions and Fe3+. The low LOD value of 1.032µM suggested that the molecule is highly sensitive towards Fe3+. A high quantum yield of 8.087% increased the possibility of using sensor1 for light applications. There was a 2:1 stoichiometric ratio between sensor1 and Fe3+. The FTIR data analysis confirmed the presence of functional groups S = O, C-O-C, etc. The average particle size found with the DLS method was 130.5nm. The zeta potential of -12.7mV indicated that sensor1 is quite stable in solution form. For logic gate application EDTA (Ethylenediaminetetraaceticacid) and Fe3+ were considered as inputs and fluorescence intensity was taken as an output. In thermal sensing application, the high value of activation energy i.e 908meV and relative sensitivity of 1.2% 0C−1 affirmed that sensor1 can be used for thermal applications. The sensor1 was also apt for fluorescent ink application. Hence this investigation deduced that sensor1 can be a potential candidate for such applications over other conventional synthesized fluorescent probes.

Phytochemical potential and antioxidant activity of Phaseolus vulgaris .L (Var, Sidi Ferredj) in the face of salt stress

2019 ◽  
Vol 9 (2) ◽  
pp. 72-79
Author(s):  
Laredj-Zazou Rahma ◽  
Toumi-Benali Fawzia ◽  
Tifouri Zineb
Keyword(s):  
Antioxidant Activity ◽  
Salt Stress ◽  
Phenolic Compounds ◽  
Condensed Tannins ◽  
Total Phenols ◽  
Phaseolus Vulgaris L ◽  
Technical Institute ◽  
The Face ◽  
Coastal Soils ◽  
The Subject

Phaseolus vulgaris.L (var, Sidi Ferredj), a local fabaceae, (creation by the services of the technical institute of vegetable and industrial crops: ITCMI Algeria, after adaptation to the coastal soils), has proven its capability for tolerance to salt stress, through its phytochemical potential, allowing it to resist this abiotic constraint. The objective of our study was to highlight the metabolic capital, in particular the phenolic compounds synthesized by P. vulgaris.L (var, Sidi Ferredj), subjected to salt stress at different concentrations and to valorize this capital by antioxidant activity. Potting trials of the species, which were the subject of our study, were conducted in a greenhouse and under semi-controlled conditions, applying salt stress induced by irrigation with increasing salinity solutions. NaCl-based (0.50,100 and 200 meq.l-1) and a second one based on a combination of NaCl and CaCl2 salts (100 and 150 meq.l-1); the study was completed by the quantification of the phytochemical potential in response to this salinity stress, and which were total phenols, flavonoids and tannins . The antioxidant potential was assessed according to the DPPH test. The results obtained showed that the concentrations of NaCl (50 and 100 meq.l-1) stimulated the accumulation of phenolic compounds, with remarkable contents of total phenols, flavonoids and condensed tannins, unlike the concentration of 200 meq.l-1 NaCl, which appeared to be unfavourable and induced a reduction, particularly total phenols, while the antioxidant activity raised with the increase in salt stress.

Sign in / Sign up

Export Citation Format

Share Document