scholarly journals Peroxide-Dependent Analyte Conversion by the Heme Prosthetic Group, the Heme Peptide “Microperoxidase-11” and Cytochrome c on Chitosan Capped Gold Nanoparticles Modified Electrodes

Biosensors ◽  
2012 ◽  
Vol 2 (2) ◽  
pp. 189-204 ◽  
Author(s):  
Aysu Yarman ◽  
Bettina Neumann ◽  
Maria Bosserdt ◽  
Nenad Gajovic-Eichelmann ◽  
Frieder W. Scheller
Keyword(s):  
Gold Nanoparticles ◽  
Cytochrome C ◽  
Modified Electrodes ◽  
Prosthetic Group ◽  
Heme Prosthetic Group

scholarly journals Heme-a, the heme prosthetic group of cytochrome c oxidase, is increased in Alzheimer's disease

2009 ◽  
Vol 461 (3) ◽  
pp. 302-305 ◽  
Author(s):  
Barney E. Dwyer ◽  
Meghan L. Stone ◽  
Nadia Gorman ◽  
Peter R. Sinclair ◽  
George Perry ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Prosthetic Group ◽  
Heme Prosthetic Group

Cytochrome c and cytochrome c oxidase interactions: the effects of ionic strength and hydrostatic pressure studied with site-specific modifications of cytochrome c

1992 ◽  
Vol 70 (7) ◽  
pp. 539-547 ◽  
Author(s):  
Jack A. Kornblatt ◽  
Janice Theodorakis ◽  
Gaston Hui Bon Hoa ◽  
Emmanuel Margoliash
Keyword(s):  
Hydrostatic Pressure ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Cytochrome C Oxidase ◽  
Front Surface ◽  
Prosthetic Group ◽  
Binding Interaction ◽  
Cytochromes C ◽  
Heme Prosthetic Group ◽  
Full Charge

Seven cytochromes c, in which individual lysines have been modified to the propylthiobimane derivatives, have been prepared. These derivatives were also converted to the porphyrin cytochromes c by treatment with HF. The properties of both types of modified proteins were studied in their reactions with cytochrome c oxidase. The results show that lysines 25, 27, 60, 72, and 87 do not contribute a full charge to the binding interaction with the oxidase. These five residues, with the exception of the lysine-60 derivative, are on the front surface of the protein and contain the solvent-accessible edge of the heme prosthetic group. By contrast, lysines 8 and 13 at the top of the front surface do contribute a full charge to the binding interaction with the oxidase. The removal of the positive charge on any one lysine weakens the binding to cytochrome c oxidase by at least 1 kcal (1 cal = 4.1868 J). The presence of bimane at lysines 13 and 87 clearly forces the separation of the cytochrome c and oxidase, but this does not occur with the other complexes. The bimane-modified lysine-13 protein, and to a lesser extent that modified at lysine 8, show the interesting effect of enhanced complex formation with cytochrome c oxidase when subjected to pressure, possibly because of entrapment of water at the newly created interface of the complex. Our observations indicate that the two proteins of the cytochrome c – cytochrome oxidase complex have preferred, but not obligatory, spatial orientations and that interaction occurs without either protein losing significant portions of its hydration shell.Key words: cytochrome oxidase, cytochrome c, binding, hydrostatic pressure.

Biocatalytic oxidation of polycyclic aromatic hydrocarbons in media containing organic solvents

1997 ◽  
Vol 36 (10) ◽  
pp. 37-44 ◽  
Author(s):  
Eduardo Torres ◽  
Raunel Tinoco ◽  
Rafael Vazquez-Duhalt
Keyword(s):  
Cytochrome C ◽  
Organic Solvents ◽  
Oxidation Mechanism ◽  
Site Directed Mutagenesis ◽  
Solvent Mixtures ◽  
Reaction Products ◽  
Prosthetic Group ◽  
Mass Transfer Limitation ◽  
Polycyclic Aromatic ◽  
Protein Environment

Lignin peroxidase, cytochrome c and haemoglobin were tested for oxidation of polycyclic aromatic hydrocarbon (PAH) in the presence of hydrogen peroxide. The reaction mixture Contained water-miscible organic solvents in order to reduce the mass transfer limitation of hydrophobic substrates. The reaction products from all three haemoproteins were mainly quinones, suggesting the same oxidation mechanism for the three biocatalysts. The haeme prosthetic group must have located in a protein environment for it to catalyze these reactions, and only certain types of protein environment are able to induce this type of haemebased catalytic activity. The solvent hydrophobicity is a factor affecting the biocatalysis in organic media. Substrate partitioning between the active site (haeme) and the bulk solvent is the main factor of the biocatalytic behaviour in organic solvent mixtures. Site-directed mutagenesis of yeast cytochrome c significantly altered the kinetic behaviour of the protein. The Gly82;Thr 102 variant was 10 times more active and showed a catalytic efficiency 10-fold greater than the wild-type iso-1-cytochrome c. These results suggest that it is possible to design a new biocatalyst for environmental purposes.

scholarly journals Ultrasensitive and label free electrochemical immunosensor for detection of ROR1 as an oncofetal biomarker using gold nanoparticles assisted LDH/rGO nanocomposite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rozita Abolhasan ◽  
Balal Khalilzadeh ◽  
Hadi Yousefi ◽  
Sahar Samemaleki ◽  
Forough Chakari-Khiavi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Flexible Structures ◽  
Modified Electrodes ◽  
Electrochemical Immunosensor ◽  
Lymphocytic Leukemia ◽  
Orphan Receptor ◽  
Detection Sensitivity ◽  
Label Free ◽  
Serum Samples ◽  
Limit Of Quantification

AbstractIn the present article, we developed a highly sensitive label-free electrochemical immunosensor based on NiFe-layered double hydroxides (LDH)/reduced graphene oxide (rGO)/gold nanoparticles modified glassy carbon electrode for the determination of receptor tyrosine kinase-like orphan receptor (ROR)-1. In this electrochemical immunoassay platform, NiFe-LDH/rGO was used due to great electron mobility, high specific surface area and flexible structures, while Au nanoparticles were prepared and coated on the modified electrodes to improve the detection sensitivity and ROR1 antibody immobilizing (ROR1Ab). The modification procedure was approved by using cyclic voltammetry and differential pulse voltammetry based on the response of peak current to the step by step modifications. Under optimum conditions, the experimental results showed that the immunosensor revealed a sensitive response to ROR1 in the range of 0.01–1 pg mL−1, and with a lower limit of quantification of 10 attogram/mL (10 ag mL−1). Furthermore, the designed immunosensor was applied for the analysis of ROR1 in several serum samples of chronic lymphocytic leukemia suffering patients with acceptable results, and it also exhibited good selectivity, reproducibility and stability.

Integrating cell-free biosyntheses of heme prosthetic group and apoenzyme for the synthesis of functional P450 monooxygenase

2012 ◽  
Vol 110 (4) ◽  
pp. 1193-1200 ◽  
Author(s):  
Yong-Chan Kwon ◽  
In-Seok Oh ◽  
Nahum Lee ◽  
Kyung-Ho Lee ◽  
Yeo Joon Yoon ◽  
...  
Keyword(s):  
Prosthetic Group ◽  
P450 Monooxygenase ◽  
Heme Prosthetic Group

scholarly journals Nitrone Modified Gold Nanoparticles: Synthesis, Characterization and Their Potential as 18F-Labeled PET Probes via I-SPANC

2019 ◽  
Author(s):  
Sara Ghiassian ◽  
Lihai Yu ◽  
Pierangelo Gobbo ◽  
Ali nazemi ◽  
Tommaso Romagnoli ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Nmr Spectroscopy ◽  
Gold Nanoparticle ◽  
Molecular Level ◽  
Prosthetic Group ◽  
H Nmr ◽  
Nanoparticles Synthesis ◽  
Interfacial Strain ◽  
Pet Probes ◽  
High Degree

A bioorthogonal gold nanoparticle template displaying interfacial nitrone functional groups for bioorthogonal interfacial strain-promoted alkyne-nitrone cycloaddition (I-SPANC) reactions has been synthesized. The Nitrone-AuNPs were characterized in detail using <sup>1</sup>H NMR spectroscopy, TEM, TGA, and XPS and a nanoparticle raw formula was calculated. The ability to control the conjugation of molecules of interest at the molecular level onto the Nitrone-AuNPs template allowed us to create a methodology for the synthesis of AuNP-based radiolabeled probes with a high degree of loading using copper free, strained-promoted cycloaddition. To this end, we also describe the synthesis of a new prosthetic group containing a strained-alkyne capable of clicking hot <sup>18</sup>F-label onto complementary azide or nitrone labelled agents.

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