scholarly journals Thermodynamics of hydrogen cyanide and hydrogen fluoride binding to cytochrome c peroxidase and its Asn-82→Asp mutant

1994 ◽  
Vol 302 (2) ◽  
pp. 437-442 ◽  
Author(s):  
S F DeLauder ◽  
J M Mauro ◽  
T L Poulos ◽  
J C Williams ◽  
F P Schwarz
Keyword(s):  
Cytochrome C ◽  
Binding Constant ◽  
Binding Constants ◽  
Cytochrome C Peroxidase ◽  
Titration Calorimetry ◽  
Difference Spectroscopy ◽  
Cyanide Binding ◽  
Order Of Magnitude ◽  
Binding Enthalpy ◽  
Entropic Effects

The thermodynamics of binding of fluoride and cyanide to cytochrome c peroxidase (CCP) and its Asn-82-->Asp mutant (D82CCP) in phosphate and acetate buffer at an ionic strength of 0.15 mol.kg-1 from pH 5.0 to 7.1 were investigated by titration calorimetry at 289 and 297 K. The binding reactions are enthalpically driven. The fluoride-binding constants determined from the titration calorimetry results were in agreement with those determined from difference-spectroscopy measurements. For cyanide binding to CCP at 297.9 K, the binding constant decreased from 8.95 (+/- 0.83) x 10(5) M-1 at pH 7.0 to 4.04(+/- 0.23) x 10(5) M-1 at pH 5.0, and the binding enthalpy increased from -57.2 +/- 1.4 kJ.mol-1 at pH 7.0 to -48.6 +/- 1.8 kJ.mol-1 at pH 5.0. For fluoride binding to CCP, the binding constant increased from 8.41(+/- 0.54) x 10(3) M-1 at pH 7.0 to 3.11(+/- 0.09) x 10(5) M-1 at pH 5.0 and the binding enthalpy increased from -71.9 +/- 1.1 kJ.mol-1 at pH 7.0 to -67.0 +/- 1.9 kJ.mol-1 at pH 5.0. The binding enthalpies for D82CCP were about the same as those for CCP. However, the binding constants for cyanide and fluoride to D82CCP were respectively a factor of two less and at least an order of magnitude less than the corresponding binding constants of CCP. Decreased ligand-binding strength in the D82CCP mutant is thus entirely due to entropic effects.

scholarly journals Crystallographic determination of the heme orientation and location of the cyanide binding site in yeast cytochrome c peroxidase.

1978 ◽  
Vol 253 (10) ◽  
pp. 3730-3735
Author(s):  
T.L. Poulos ◽  
S.T. Freer ◽  
R.A. Alden ◽  
N.H. Xuong ◽  
S.L. Edwards ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Binding Site ◽  
Cytochrome C Peroxidase ◽  
Cyanide Binding

scholarly journals Apolar distal pocket mutants of yeast cytochrome c peroxidase: Hydrogen peroxide reactivity and cyanide binding of the TriAla, TriVal, and TriLeu variants

2013 ◽  
Vol 1834 (1) ◽  
pp. 137-148 ◽  
Author(s):  
Anil K. Bidwai ◽  
Cassandra Meyen ◽  
Heather Kilheeney ◽  
Damian Wroblewski ◽  
Lidia B. Vitello ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cytochrome C ◽  
Cytochrome C Peroxidase ◽  
Cyanide Binding

scholarly journals The specificity of the interaction of bovine pancreatic ribonuclease A with natural and halogenated purine nucleotides

1978 ◽  
Vol 175 (1) ◽  
pp. 21-27 ◽  
Author(s):  
X Pares ◽  
C Arus ◽  
R Llorens ◽  
C M Cuchillo
Keyword(s):  
Binding Constants ◽  
Ribonuclease A ◽  
Difference Spectroscopy ◽  
Enzyme Molecule ◽  
Purine Nucleotides ◽  
Hydrophobic Region ◽  
Pancreatic Ribonuclease ◽  
Affinity Labelling ◽  
Order Of Magnitude ◽  
Pancreatic Ribonuclease A

The interaction between bovine pancreatic ribonuclease A (EC 3.1.4.22) and the purine nucleotides AMP, GMP, 6-chloropurine 5′-ribonucleotide and 8-bromoadenosine 5′-monophosphate was studied by u.v. difference spectroscopy. The stoicheiometry of the binding of the halogenated nucleotides to the enzyme shows a 1:1 ratio, as for the natural ones. The binding constants, Ka, for all four nucleotides at pH 5.5 were determined. They are within the same order of magnitude, though the nucleotides with a 6-amino group show a stronger interaction. The magnitude of the binding shows a reciprocal dependence on the ionic strength, which indicates an electrostatic interaction between ligand and enzyme. Finally, solvent-perturbation experiments show that all four nucleotides bind to the enzyme in a partially hydrophobic region. It is concluded that both halogenated and natural purine ribonucleotides interact in a similar manner with the enzyme molecule. The special synthesis and identification of 6-chloropurine 5′-ribonucleotide are discussed extensively. It is concluded that both halogenated and natural purine ribonucleotides interact in a similar manner with the enzyme molecule and thus the halogenated analogues are potential reagents for the affinity labelling of the purine-binding site.

Thermodynamic Analysis of Chitooligosaccharide Binding to Urtica dioica agglutinin by Isothermal Titration Calorimetry

1999 ◽  
Vol 19 (5) ◽  
pp. 411-419 ◽  
Author(s):  
Samiksha Katiyar ◽  
E. J. M. Van Damme ◽  
Willy J. Peumans ◽  
Avadhesha Surolia
Keyword(s):  
Thermodynamic Parameters ◽  
Isothermal Titration Calorimetry ◽  
Thermodynamic Analysis ◽  
Binding Constant ◽  
Urtica Dioica ◽  
Titration Calorimetry ◽  
Sugar Residue ◽  
Binding Enthalpy ◽  
Urtica Dioica Agglutinin

UDA (Urtica dioica agglutinin) contains two hevein like domains with two non-identical interacting sites and is specific for chitooligosaccharides. The binding of chitooligosaccharides to UDA was studied by Isothermal Titration Calorimetry. Each site is composed of three subsites, each binding to a sugar residue. Thermodynamic parameters obtained show that while chitobiose has two independent non-interacting sites, chitotriose, chitotetrose and chitopentose have two interacting sites on each monomer of UDA. Values of binding enthalpy (ΔH) increase almost by a factor of 7 in going from chitobiose to chitotriose indicating the existence of three subsites in the combining site of UDA. The binding constant for chitotetrose and chitopentose increase without any further enhancement in the values of ΔH indicating that for oligomers larger than chitotriose interaction is favoured entropically.

Binding of Yeast Cytochrome c to Forty-Four Charge-Reversal Mutants of Yeast Cytochrome c Peroxidase: Isothermal Titration Calorimetry

Biochemistry ◽  
2015 ◽  
Vol 54 (31) ◽  
pp. 4845-4854 ◽  
Author(s):  
James E. Erman ◽  
Lidia B. Vitello ◽  
Naw May Pearl ◽  
Timothy Jacobson ◽  
Meka Francis ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Isothermal Titration Calorimetry ◽  
Cytochrome C Peroxidase ◽  
Titration Calorimetry ◽  
Charge Reversal

Kinetics of cyanide binding by half-reduced Pseudomonas cytochrome c peroxidase

1985 ◽  
Vol 828 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Marjaana Rönnberg ◽  
Anne-Marie Lambeir ◽  
Nils Ellfolk ◽  
H.Brian Dunford
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Peroxidase ◽  
Cyanide Binding ◽  
Kinetics Of

scholarly journals Complex-formation between cytochrome c and cytochrome c peroxidase. Equilibrium and titration studies

1971 ◽  
Vol 121 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Eugene Mochan ◽  
P. Nicholls
Keyword(s):  
Cytochrome C ◽  
Complex Formation ◽  
Column Chromatography ◽  
Binding Constants ◽  
Cytochrome C Peroxidase ◽  
Peroxide Compound ◽  
Ferrocytochrome C ◽  
Kinetic Predictions ◽  
Ferricytochrome C ◽  
C Complex

1. Physical studies of complex-formation between cytochrome c and yeast peroxidase are consistent with kinetic predictions that these complexes participate in the catalytic activity of yeast peroxidase towards ferrocytochrome c. Enzyme–ferricytochrome c complexes have been detected both by the analytical ultracentrifuge and by column chromatography, whereas an enzyme–ferrocytochrome c complex was demonstrated by column chromatography. Estimated binding constants obtained from chromatographic experiments were similar to the measured kinetic values. 2. The physicochemical study of the enzyme–ferricytochrome c complex, and an analysis of its spectrum and reactivity, suggest that the conformation and reactivity of neither cytochrome c nor yeast peroxidase are grossly modified in the complex. 3. The peroxide compound of yeast cytochrome c peroxidase was found to have two oxidizing equivalents accessible to cytochrome c but only one readily accessible to ferrocyanide. Several types of peroxide compound, differing in available oxidizing equivalents and in reactivity with cytochrome c, seem to be formed by stoicheiometric amounts of hydrogen peroxide. 4. Fluoride combines not only with free yeast peroxidase but also with peroxidase–peroxide and accelerates the decomposition of the latter compound. The ligand-catalysed decomposition provides evidence for one-electron reduction pathways in yeast peroxidase, and the reversible binding of fluoride casts doubt upon the concept that the peroxidase–peroxide intermediate is any form of peroxide complex. 5. A mechanism for cytochrome c oxidation is proposed involving the successive reaction of two reversibly bound molecules of cytochrome c with oxidizing equivalents associated with the enzyme protein.

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