Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry.
Publisher:
Springer,
Frequency: Eight no. a year, 2001-
Country: Germany
Language: English
Author(s):
Society of Biological Inorganic Chemistry.
Start Year:1996 -
ISSN:
0949-8257 (Print)
1432-1327 (Electronic)
0949-8257 (Linking)
1432-1327 (Electronic)
0949-8257 (Linking)
Impact Factor
3
2022
| NLM ID: | 9616326 |
| (DNLM): | SR0085484(s) |
| (OCoLC): | 36118565 |
| Coden: | JJBCFA |
| LCCN: | sn 96039945 |
| Classification: | W1 JO564CP |
Interaction of dimeric horse cytochrome c with cyanide ion. We have previously shown that methionine-heme iron coordination is perturbed in domain-swapped dimeric horse cytochrome c. To gain insight into the effect of methionine dissociation in dimeric cytochrome c, we investigated its interaction with cyanide ion. We found that the Soret and Q bands of oxidized dimeric cytochrome c at 406.5 and 529 nm redshift to 413 and 536 nm, respectively, on addition of 1 mM cyanide ion. The binding constant of dimeric cytochrome c and cyanide ion was obtained as 2.5 × 10(4) M(-1). The Fe-CN and C-N stretching (ν (Fe-CN) and ν (CN)) resonance Raman ba...
Correlation of acid-induced conformational transition of ferricytochrome c with cyanide binding kinetics. A relation between pH-induced conformational transitions of horse heart ferricytochrome c and the kinetics of external ligand coordination to heme iron was investigated by optical spectroscopy, circular dichroism and viscometry. The dependencies of both the association, k (a), and dissociation rate constants of cyanide binding on pH were determined from kinetic measurements. The association rate constant exhibits a bell-shaped form of dependence on pH in the region where this protein unfolds. The maximum of the dependence of k (a) on pH is found to be coincident with the pK values of conformat...
Ruthenium anticancer drugs and proteins: a study of the interactions of the ruthenium(III) complex imidazolium trans-[tetrachloro(dimethyl sulfoxide)(imidazole)ruthenate(III)] with hen egg white lysozyme and horse heart cytochrome c. The interactions with protein targets of the ruthenium(III) complex imidazolium trans-[tetrachloro(dimethyl sulfoxide)(imidazole)ruthenate(III)], NAMI-A, an effective anticancer and antimetastatic agent now in clinical trials, deserve great attention as they are believed to be at the basis of the mechanism of action of this innovative molecule. Here, we report on the reactions of NAMI-A with two well-known model proteins, namely, hen egg white lysozyme and horse heart cytochrome c; these reactions were investigated by a variety of physicochemical methods, including optical spectroscopy, (1)H N...
Ferritin-catalyzed consumption of hydrogen peroxide by amine buffers causes the variable Fe2+ to O2 stoichiometry of iron deposition in horse spleen ferritin. Ferritin catalyzes the oxidation of Fe2+ by O2 to form a reconstituted Fe3+ oxy-hydroxide mineral core, but extensive studies have shown that the Fe2+ to O2 stoichiometry changes with experimental conditions. At Fe2+ to horse spleen ferritin (HoSF) ratios greater than 200, an upper limit of Fe2+ to O2 of 4 is typically measured, indicating O2 is reduced to 2H2O. In contrast, a lower limit of Fe2+ to O2 of approximately 2 is measured at low Fe2+ to HoSF ratios, implicating H2O2 as a product of Fe2+ deposition. Stoichiometric amounts of H2O2 have not been measured, and H2O2 is proposed to react ...
Volume and enthalpy profiles of CO rebinding to horse heart myoglobin. Carbon monoxide binding to myoglobin was characterized using the photothermal beam deflection method. The volume and enthalpy changes coupled to CO dissociation were found to be 9.3+/-0.8 mL x mol(-1) and 7.4+/-2.8 kcal x mol(-1), respectively. The corresponding values observed for CO rebinding have the same magnitude but opposite sign: Delta V=-8.6+/-0.9 mL x mol(-1) and Delta H=-5.8+/-2.9 kcal x mol(-1). Ligand rebinding occurs as a single conformational step with a rate constant of 5 x 10(5) M(-1) s(-1) and with activation enthalpy of 7.1+/-0.8 kcal x mol(-1) and activation entropy of -22.4...
Competition studies in horse spleen ferritin probed by a kinetically inert inhibitor, [Cr(TREN)(H(2)O)(OH)](2+), and a highly luminescent Tb(III) reagent. The ability of ferritin as an Fe(II) detoxifier and Fe(III) storage protein is limited by its ability to recognize and incorporate Fe(II), which is then oxidized and mineralized at internal protein sites. The Cr(III) amine complex [Cr(N(CH(2)CH(2)NH(2))(3)(H(2)O)(OH)](2+) [abbreviated as Cr(TREN)] is a kinetically inert inhibitor of iron incorporation and mineralization in ferritin. Unlike other inhibitors, Cr(TREN) can only exchange its two aqua/hydroxy ligands. Competition studies between Cr(TREN) and Tb(III) binding have been performed in horse spleen ferritin (HoSF) to probe uptake of Fe(I...
Spectroscopic and electrochemical studies of horse myoglobin in dimethyl sulfoxide. This paper reports the first report of rapid, reversible direct electron transfer between a redox protein, specifically, horse myoglobin, and a solid electrode substrate in nonaqueous media and the spectroscopic (UV-vis, fluorescence, and resonance Raman) characterization of the relevant redox forms of myoglobin (Mb) in dimethyl sulfoxide (DMSO). In DMSO, the heme active site of metmyoglobin (metMb) appears to remain six-coordinate high-spin, binding water weakly. Changes in the UV-fluorescence spectra for metMb in DMSO indicate that the protein secondary structure has been perturbed and sugge...