scholarly journals Mercury(II) binds to both of chymotrypsin's histidines, causing inhibition followed by irreversible denaturation/aggregation

2017 ◽  
Vol 26 (2) ◽  
pp. 292-305 ◽  
Author(s):  
Amanda Stratton ◽  
Matthew Ericksen ◽  
Travis V. Harris ◽  
Nick Symmonds ◽  
Todd P. Silverstein
Keyword(s):  
Irreversible Denaturation

scholarly journals Half-sites oxidation of bovine liver uridine diphosphate glucose dehydrogenase

1978 ◽  
Vol 173 (2) ◽  
pp. 701-704 ◽  
Author(s):  
J S Franzen ◽  
P Marchetti ◽  
R Ishman ◽  
J Ashcom
Keyword(s):  
Catalytic Activity ◽  
Glucose Dehydrogenase ◽  
Bovine Liver ◽  
Thiol Group ◽  
Catalytic Site ◽  
Uridine Diphosphate ◽  
Thiol Groups ◽  
Irreversible Denaturation ◽  
Diphosphate Glucose ◽  
Uridine Diphosphate Glucose Dehydrogenase

6,6-Dithiodinicotinate shows half-of-the-sites reactivity towards the six catalytic-site thiol groups of bovine liver UDP-glucose dehydrogenase. The reagent introduces three intrasubunit disulphide linkages between catalytic-site thiol groups and non-catalytic-site thiol groups and abrogates 60% of the catalytic activity of the hexameric enzyme; excess 2-mercaptoethanol rapidly restores full catalytic activity. These results show the half-of-the-sites behaviour of the enzyme with the reagent and the presence of a non-catalytic-site thiol group capable of forming a disulphide linkage with a catalytic-site thiol group on the same subunit without irreversible denaturation.

Expression of Psychrophilic Genes in Mesophilic Hosts: Assessment of the Folding State of a Recombinant α-Amylase

1998 ◽  
Vol 64 (3) ◽  
pp. 1163-1165 ◽  
Author(s):  
Georges Feller ◽  
Olivier Le Bussy ◽  
Charles Gerday
Keyword(s):  
Escherichia Coli ◽  
Enzyme Stability ◽  
Expression System ◽  
Wild Strain ◽  
Culture Temperature ◽  
E Coli ◽  
System A ◽  
Irreversible Denaturation ◽  
The Antarctic ◽  
Folding State

ABSTRACT α-Amylase from the antarctic psychrophile Alteromonas haloplanktis is synthesized at 0 ± 2°C by the wild strain. This heat-labile α-amylase folds correctly when overexpressed in Escherichia coli, providing the culture temperature is sufficiently low to avoid irreversible denaturation. In the described expression system, a compromise between enzyme stability and E. coli growth rate is reached at 18°C.

scholarly journals Temperature stability of proteins: Analysis of irreversible denaturation using isothermal calorimetry

2017 ◽  
Vol 85 (11) ◽  
pp. 2009-2016 ◽  
Author(s):  
Arne Schön ◽  
Benjamin R. Clarkson ◽  
Maria Jaime ◽  
Ernesto Freire
Keyword(s):  
Isothermal Calorimetry ◽  
Temperature Stability ◽  
Irreversible Denaturation

Peculiarities of thermal denaturation of OmpF porin from Yersinia ruckeri

2017 ◽  
Vol 13 (9) ◽  
pp. 1854-1862 ◽  
Author(s):  
Olga D. Novikova ◽  
Dmitry K. Chistyulin ◽  
Valentina A. Khomenko ◽  
Evgeny V. Sidorin ◽  
Natalya Yu. Kim ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Thermal Denaturation ◽  
Water Soluble ◽  
Yersinia Ruckeri ◽  
Multidomain Proteins ◽  
Multistage Process ◽  
Ompf Porin ◽  
Irreversible Denaturation ◽  
Detergent Solutions

Irreversible denaturation of membrane proteins in detergent solutions is similar to unfolding of water-soluble multidomain proteins and represents a complex, multistage process.

scholarly journals Butyrylcholine Esterase: Influence of pH on Enzyme Activity and Irreversible Denaturation.

1959 ◽  
Vol 13 ◽  
pp. 1255-1256 ◽  
Author(s):  
Edith Heilbronn ◽  
Matti Kreula ◽  
Martti Kiesvaara ◽  
B. Högberg ◽  
P. Kneip ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Irreversible Denaturation ◽  
Influence Of Ph

Some Properties of a DNA -Dependent RNA Polymerase from Halobacterium cutirubrum

1973 ◽  
Vol 51 (9) ◽  
pp. 1297-1304 ◽  
Author(s):  
L. L. Chazan ◽  
S. T. Bayley
Keyword(s):  
High Speed ◽  
Enzyme Preparation ◽  
Nearest Neighbor ◽  
Equal Proportion ◽  
Trichloracetic Acid ◽  
Sephadex Column ◽  
Membrane Complex ◽  
Irreversible Denaturation ◽  
Insoluble Product ◽  
Dna Template

A DNA–protein–membrane complex, which incorporated ribonucleoside triphosphates (rNTP's) into a cold trichloracetic acid insoluble product, was isolated from an homogenate of the extremely halophilic Halobacterium cutirubrum by high speed centrifugation. After digestion with DNase and chromatography on a Sephadex column, the complex yielded an enzyme preparation which incorporated rNTP's in the presence of added DNA. Incorporation by both the complex and the enzyme preparation depended on all four rNTP's and was sensitive to DNase and RNase. Nearest-neighbor analyses showed that the product from the partially purified enzyme contained all four rNTP's in roughly equal proportion. The enzyme was inhibited by actinomycin D and acriflavin but not by rifampicin or streptovaricin. It showed no specificity for DNA templates. From Sephadex chromatography and centrifugation on glycerol gradients, its molecular weight was estimated to be roughly 300 000 – 400 000 daltons.For incorporation, the optimum Mg2+ concentration was 40 mM. The complex was active at all concentrations of KCl or NH4Cl up to saturation, but the partially purified enzyme was active only below 0.4 M. The lack of activity at higher concentrations was not due to irreversible denaturation of the enzyme but concentrated salt may have inhibited the reaction by altering the configuration of the DNA template.

Reversible and irreversible denaturation processes in globular proteins: from collective to molecular spectroscopic analysis

2011 ◽  
Vol 43 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Paola Sassi ◽  
Stefania Perticaroli ◽  
Lucia Comez ◽  
Laura Lupi ◽  
Marco Paolantoni ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Globular Proteins ◽  
Irreversible Denaturation

scholarly journals Are babies of vaccinated Pregnant and lactating mothers with ChAdOx1 AstraZeneca covid vaccine more risk for zinc deficiency and SCID disease.

2021 ◽  
Author(s):  
Amr Kamel Khalil Ahmed ◽  
Mahmoud Elkazzaz
Keyword(s):  
Protein Interactions ◽  
Chelating Agent ◽  
Normal Structure ◽  
Zinc Ion ◽  
Metabolic Enzyme ◽  
Crystallographic Structure ◽  
Lactating Mothers ◽  
Irreversible Denaturation ◽  
Potential Damage ◽  
High Degree

AstraZeneca's covid-19 vaccine demonstrates some concerns regarding its excipients, such as polysorbate 80, which serves as a stabilizer, and EDTA, which serves as a binding agent. 7 ADA is a critical purine metabolic enzyme required for adequate immunological competence. The current study examines the effect of Zn2+ on the maintenance of ADA. After eliminating Zn2+, the protein's crystallographic structure has retained a high degree of order and similarity to the original one, with some alterations limited to the areas surrounding the pocket. However, the protein's stability has been dramatically reduced. EDTA is a highly effective zinc-chelating agent employed in the investigations of protein interactions. The potential damage of the structure and interactions of zinc-binding proteins by EDTA treatment must be considered. Excess Zn2+ has not returned C/H1 to its normal structure, highlighting the irreversible denaturation induced by the EDTA. Around 30% of proteins in cells form complexes with metals. Metal ions are essential not just for regulating biological functions but also for stabilizing proteins. (ADA, EC 3.5.4.4) has a molecular mass of 40 kDa and contains a firmly attached zinc ion essential for its activity. The lack of its enzymatic activity leads to malfunction B and T cells, and SCID development

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