Chemical synthesis of disulfide surrogate peptides by using beta-carbon dimethyl modified diaminodiacids

2021 ◽  
Author(s):  
jibin cui ◽  
xiaoxiong wei ◽  
Rui Zhao ◽  
Huixia Zhu ◽  
Jing Shi ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Reducing Agents ◽  
Disulfide Bridges ◽  
Promising Strategy ◽  
The Stability

The replacement of disulfide bridges with metabolically stable isosteres is a promising strategy to improve the stability of disulfide-rich polypeptides towards reducing agents and isomerases. Diaminodiacid-based strategy is one of...

Methods for the Concentration of Bovine Ac-Globulin (Factor V)

1961 ◽  
Vol 06 (03) ◽  
pp. 435-444 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers
Keyword(s):  
Room Temperature ◽  
Barium Carbonate ◽  
Deae Cellulose ◽  
Reducing Agents ◽  
Factor V ◽  
Isoelectric Precipitation ◽  
Stabilizing Agent ◽  
Bovine Plasma ◽  
The Stability

SummaryAn attempt was made to obtain Ac-globulin from bovine plasma. The concentrates contain mostly protein, and phosphorus is also present. The stability characteristics vary from one preparation to another, but in general there was no loss before 1 month in a deep freeze or before 1 week in an icebox, or before 5 hours at room temperature. Reducing agents destroy the activity rapidly. S-acetylmercaptosuccinic anhydride is an effective stabilizing agent. Greatest stability was at pH 6.0.In the purification bovine plasma is adsorbed with barium carbonate and diluted 6-fold with water. Protein is removed at pH 6.0 and the Ac-globulin is precipitated at pH 5.0. Rivanol and alcohol fractionation is followed by chromatography on Amberlite IRC-50 or DEAE-cellulose. The final product is obtained by isoelectric precipitation.

scholarly journals Chemical Synthesis and Characterization of Maurotoxin, a Short Scorpion Toxin with four Disulfide Bridges that Acts on K+ Channels

1996 ◽  
Vol 242 (3) ◽  
pp. 491-498 ◽  
Author(s):  
Ryadh Kharrat ◽  
Kamel Mabrouk ◽  
Marcel Crest ◽  
Herve Darbon ◽  
Razika Oughideni ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Scorpion Toxin ◽  
Synthesis And Characterization ◽  
Disulfide Bridges ◽  
K Channels

Noncovalent functionalization of hole-transport materials with multi-walled carbon nanotubes for stable inverted perovskite solar cells

2019 ◽  
Vol 7 (45) ◽  
pp. 14306-14313 ◽  
Author(s):  
Yu Lu ◽  
Xueping Zong ◽  
Yilei Wang ◽  
Wenhua Zhang ◽  
Quanping Wu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Promising Strategy ◽  
Noncovalent Functionalization ◽  
Multi Walled Carbon Nanotubes ◽  
The Stability ◽  
Walled Carbon Nanotubes

A new promising strategy to improve the stability of inverted perovskite solar cells is reported.

Control of oxidation-reduction potential during Cheddar cheese ripening and its effect on the production of volatile flavour compounds

2016 ◽  
Vol 83 (4) ◽  
pp. 479-486 ◽  
Author(s):  
Veronica Caldeo ◽  
John A Hannon ◽  
Dara-Kate Hickey ◽  
Dave Waldron ◽  
Martin G Wilkinson ◽  
...  
Keyword(s):  
Redox Potential ◽  
Cheddar Cheese ◽  
Principal Component ◽  
Reducing Agents ◽  
Sulphur Compounds ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Volatile Flavour ◽  
Redox Agents ◽  
The Stability

In cheese, a negative oxidation-reduction (redox) potential is required for the stability of aroma, especially that associated with volatile sulphur compounds. To control the redox potential during ripening, redox agents were added to the salted curd of Cheddar cheese before pressing. The control cheese contained only salt, while different oxidising or reducing agents were added with the NaCl to the experimental cheeses. KIO3 (at 0·05, 0·1 and 1%, w/w) was used as the oxidising agent while cysteine (at 2%, w/w) and Na2S2O4 (at 0·05 and 0·1%, w/w) were used as reducing agents. During ripening the redox potential of the cheeses made with the reducing agents did not differ significantly from the control cheese (Eh ≈ −120 mV) while the cheeses made with 0·1 and 0·05% KIO3 had a significantly higher and positive redox potential in the first month of ripening. Cheese made with 1% KIO3 had positive values of redox potential throughout ripening but no starter lactic acid bacteria survived in this cheese; however, numbers of starter organisms in all other cheeses were similar. Principal component analysis (PCA) of the volatile compounds clearly separated the cheeses made with the reducing agents from cheeses made with the oxidising agents at 2 month of ripening. Cheeses with reducing agents were characterized by the presence of sulphur compounds whereas cheeses made with KIO3 were characterized mainly by aldehydes. At 6 month of ripening, separation by PCA was less evident. These findings support the hypothesis that redox potential could be controlled during ripening and that this parameter has an influence on the development of cheese flavour.

scholarly journals A theoretical study of the stability of disulfide bridges in various β-sheet structures of protein segment models

2014 ◽  
Vol 593 ◽  
pp. 48-54 ◽  
Author(s):  
Natalie J. Galant ◽  
Heeyeon Cheryl Song ◽  
Imre Jákli ◽  
Bela Viskolcz ◽  
Imre G. Csizmadia ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Disulfide Bridges ◽  
Protein Segment ◽  
The Stability ◽  
Β Sheet

scholarly journals Pseudoperoxidase activity of 5-lipoxygenase stimulated by potent benzofuranol and N-hydroxyurea inhibitors of the lipoxygenase reaction

1991 ◽  
Vol 274 (1) ◽  
pp. 287-292 ◽  
Author(s):  
D Riendeau ◽  
J P Falgueyret ◽  
J Guay ◽  
N Ueda ◽  
S Yamamoto
Keyword(s):  
Nordihydroguaiaretic Acid ◽  
Leukotriene B4 ◽  
Reducing Agents ◽  
Lipid Hydroperoxides ◽  
Reverse Phase ◽  
Structural Analogues ◽  
The Stability ◽  
Hydroperoxyoctadecadienoic Acid ◽  
Derivatives Of ◽  
Stimulation Of

The purified 5-lipoxygenase from porcine leukocytes was found to catalyse the degradation of lipid hydroperoxides in the presence of potent inhibitors of the lipoxygenase reaction. Derivatives of diphenyl-N-hydroxyureas, 4-hydroxybenzofurans and 5-hydroxydihydrobenzofurans all stimulated the 5-lipoxygenase-mediated destruction of 13-hydroperoxyoctadecadienoic acid (13-HPOD). The reaction was dependent on inhibitor and hydroperoxide concentrations (1-10 microM) and could not be detected using heat-inactivated enzyme, when ATP and Ca2+ were omitted or when the hydroperoxide was replaced by the corresponding alcohol. The stability of the inhibitors during this pseudoperoxidase reaction was investigated by measuring the recoveries of 5-hydroxy-2-phenethyl-6-(3-phenoxypropyl)-2,3-dihydrobenzofuran and N-(4-chlorophenyl)-N-hydroxy-N'-(3-chlorophenyl)urea from the reaction mixtures using reverse-phase h.p.l.c. By using an equimolar concentration of 13-HPOD and inhibitor (10 microM) and under conditions where 50% of the 13-HPOD was consumed, the concentration of the benzofuranol decreased by 30%, whereas the N-hydroxyurea derivative could be completely recovered from the reaction mixture. A stimulation of the pseudoperoxidase reaction could be detected only with very effective inhibitors of leukotriene B4 biosynthesis by human leucocytes [IC50 (concn. causing 50% inhibition) less than 100 nM], but not with closely related structural analogues of lower potency or other inhibitors such as nordihydroguaiaretic acid, quercetin or the hydroxamate A-64077. These results demonstrate that 5-lipoxygenase possesses a pseudoperoxidase activity and indicate that potent inhibitors in both N-hydroxyurea and benzofuranol series can function as reducing agents for the enzyme.

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