| Records |
| Author |
Abbruzzetti, S.; Viappiani, C.; Sinibaldi, F.; Santucci, R. |
| Title |
Kinetics of histidine dissociation from the heme Fe(III) in N-fragment (residues 1-56) of cytochrome c |
Type |
Journal Article |
| Year |
2004 |
Publication |
The Protein Journal |
Abbreviated Journal |
Protein J |
| Volume |
23 |
Issue |
8 |
Pages |
519-527 |
| Keywords |
Animals; Cytochromes c/*chemistry; Enzyme Activation; Histidine/*chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Lasers; Ligands; Peptide Mapping; Photolysis; Spectrophotometry |
| Abstract |
We have here investigated the dissociation kinetics of the His side chains axially ligated to the heme-iron in the ferric (1-56 residues) N-fragment of horse cyt c. The ligand deligation induced by acidic pH-jump occurs as a biexponential process with different pre-exponential factors, consistent with a structural heterogeneity in solution and the presence of two differently coordinated species. In analogy with GuHCl-denatured cyt c, our data indicate the presence in solution of two ferric forms of the N-fragment characterized by bis-His coordination, as summarized in the following scheme: His18-Fe(III)-His26 <==> His18-Fe(III)-His33. We have found that the pre-exponential factors depend on the extent of the pH-jump. This may be correlated with the different pKa values shown by His26 and His33; due to steric factors, His26 binds to the heme-Fe(III) less strongly than His33, as recently shown by studies on denatured cyt c. Interestingly, the two lifetimes are affected by temperature but not by the extent of the pH-jump. The lower pKa for the deligation reaction required the use of an improved laser pH-jump setup, capable of inducing changes in H+ concentration as large as 1 mM after the end of the laser pulse. For the ferric N-fragment, close activation entropy values have been determined for the two histidines coordinated to the iron; this result significantly differs from that for GuHCl-denatured cyt c, where largely different values of activation entropy were calculated. This underlines the role played by the missing segment (residues 57-104) peptide chain in discriminating deligation of the “nonnative” His from the sixth coordination position of the metal. |
| Address |
Dipartimento di Fisica, Universita degli Studi di Parma, Parco Area delle Scienze 7/A 43100 Parma, Italy |
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Thesis |
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Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1572-3887 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:15648974 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3770 |
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| Author |
Ballew, R.M.; Sabelko, J.; Gruebele, M. |
| Title |
Direct observation of fast protein folding: the initial collapse of apomyoglobin |
Type |
Journal Article |
| Year |
1996 |
Publication |
Proceedings of the National Academy of Sciences of the United States of America |
Abbreviated Journal |
Proc. Natl. Acad. Sci. U.S.A. |
| Volume |
93 |
Issue |
12 |
Pages |
5759-5764 |
| Keywords |
Animals; Apoproteins/*chemistry; Circular Dichroism; Horses; Kinetics; Muscle, Skeletal/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Infrared; Temperature |
| Abstract |
The rapid refolding dynamics of apomyoglobin are followed by a new temperature-jump fluorescence technique on a 15-ns to 0.5-ms time scale in vitro. The apparatus measures the protein-folding history in a single sweep in standard aqueous buffers. The earliest steps during folding to a compact state are observed and are complete in under 20 micros. Experiments on mutants and consideration of steady-state CD and fluorescence spectra indicate that the observed microsecond phase monitors assembly of an A x (H x G) helix subunit. Measurements at different viscosities indicate diffusive behavior even at low viscosities, in agreement with motions of a solvent-exposed protein during the initial collapse. |
| Address |
School of Chemical Sciences and Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, 61801, USA |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0027-8424 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:8650166 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3798 |
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| Author |
Bykov, S.; Lednev, I.; Ianoul, A.; Mikhonin, A.; Munro, C.; Asher, S.A. |
| Title |
Steady-state and transient ultraviolet resonance Raman spectrometer for the 193-270 nm spectral region |
Type |
Journal Article |
| Year |
2005 |
Publication |
Applied Spectroscopy |
Abbreviated Journal |
Appl Spectrosc |
| Volume |
59 |
Issue |
12 |
Pages |
1541-1552 |
| Keywords |
Animals; Equipment Design; Equipment Failure Analysis; Horses; Kinetics; Metmyoglobin/*analysis; Myocardium/*metabolism; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Ultraviolet/*instrumentation/methods; Spectrum Analysis, Raman/*instrumentation/methods |
| Abstract |
We describe a state-of-the-art tunable ultraviolet (UV) Raman spectrometer for the 193-270 nm spectral region. This instrument allows for steady-state and transient UV Raman measurements. We utilize a 5 kHz Ti-sapphire continuously tunable laser (approximately 20 ns pulse width) between 193 nm and 240 nm for steady-state measurements. For transient Raman measurements we utilize one Coherent Infinity YAG laser to generate nanosecond infrared (IR) pump laser pulses to generate a temperature jump (T-jump) and a second Coherent Infinity YAG laser that is frequency tripled and Raman shifted into the deep UV (204 nm) for transient UV Raman excitation. Numerous other UV excitation frequencies can be utilized for selective excitation of chromophoric groups for transient Raman measurements. We constructed a subtractive dispersion double monochromator to minimize stray light. We utilize a new charge-coupled device (CCD) camera that responds efficiently to UV light, as opposed to the previous CCD and photodiode detectors, which required intensifiers for detecting UV light. For the T-jump measurements we use a second camera to simultaneously acquire the Raman spectra of the water stretching bands (2500-4000 cm(-1)) whose band-shape and frequency report the sample temperature. |
| Address |
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-7028 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:16390595 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3767 |
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| Author |
Chiba, K.; Ikai, A.; Kawamura-Konishi, Y.; Kihara, H. |
| Title |
Kinetic study on myoglobin refolding monitored by five optical probe stopped-flow methods |
Type |
Journal Article |
| Year |
1994 |
Publication |
Proteins |
Abbreviated Journal |
Proteins |
| Volume |
19 |
Issue |
2 |
Pages |
110-119 |
| Keywords |
Animals; Chromatography, Gel; Circular Dichroism; Horses; Kinetics; Metmyoglobin/analogs & derivatives/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Urea |
| Abstract |
The refolding kinetics of horse cyanometmyoglobin induced by concentration jump of urea was investigated by five optical probe stopped-flow methods: absorption at 422 nm, tryptophyl fluorescence at around 340 nm, circular dichroism (CD) at 222 nm, CD at 260 nm, and CD at 422 nm. In the refolding process, we detected three phases with rate constants of > 1 x 10(2) s-1, (4.5-9.3) s-1, and (2-5) x 10(-3) s-1. In the fastest phase, a substantial amount of secondary structure (approximately 40%) is formed within the dead time of the CD stopped-flow apparatus (10.7 ms). The kinetic intermediate populated in the fastest phase is shown to capture a hemindicyanide, suggesting that a “heme pocket precursor” recognized by hemindicyanide must be constructed within the dead time. In the middle phase, most of secondary and tertiary structures, especially around the captured hemindicyanide, have been constructed. In the slowest phase, we detected a minor structural rearrangement accompanying the ligand-exchange reaction in the fifth coordination of ferric iron. We present a possible model for the refolding process of myoglobin in the presence of the heme group. |
| Address |
Laboratory of Biodynamics, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Kanagawa, Japan |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0887-3585 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:8090705 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3799 |
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| Author |
Dunn, M.F.; Branlant, G. |
| Title |
Roles of zinc ion and reduced coenzyme in horse liver alcohol dehydrogenase catalysis. The mechanism of aldehyde activation |
Type |
Journal Article |
| Year |
1975 |
Publication |
Biochemistry |
Abbreviated Journal |
Biochemistry |
| Volume |
14 |
Issue |
14 |
Pages |
3176-3182 |
| Keywords |
*Alcohol Oxidoreductases/metabolism; Aldehydes/*pharmacology; Animals; Binding Sites; Enzyme Activation/drug effects; Horses; Hydrogen-Ion Concentration; Kinetics; Liver/enzymology; *NAD/analogs & derivatives/pharmacology; Oxidation-Reduction; Protein Binding; Spectrophotometry; Spectrophotometry, Ultraviolet; Temperature; *Zinc/pharmacology |
| Abstract |
1,4,5,6-Tetrahydronicotinamide adenine dinucleotide (H2NADH) has been investigated as a reduced coenzyme analog in the reaction between trans-4-N,N-dimethylaminocinnamaldehyde (I) (lambdamax 398 nm, epsilonmax 3.15 X 10-4 M-minus 1 cm-minus 1) and the horse liver alcohol dehydrogenase-NADH complex. These equilibrium binding and temperature-jump kinetic studies establish the following. (i) Substitution of H2NADH for NADH limits reaction to the reversible formation of a new chromophoric species, lambdamax 468 nm, epsilonmax 5.8 x 10-4 M-minus 1 cm-minus 1. This chromophore is demonstrated to be structurally analogous to the transient intermediate formed during the reaction of I with the enzyme-NADH complex [Dunn, M. F., and Hutchison, J. S. (1973), Biochemistry 12, 4882]. (ii) The process of intermediate formation with the enzyme-NADH complex is independent of pH over the range 6.13-10.54. Although studies were limited to the pH range 5.98-8.72, a similar pH independence appears to hold for the H2NADH system. (iii) Within the ternary complex, I is bound within van der Waal's contact distance of the coenzyme nicotinamide ring. (iv) Formation of the transient intermediate does not involve covalent modification of coenzyme. Based on these findings, we conclude that zinc ion has a Lewis acid function in facilitating the chemical activation of the aldehyde carbonyl for reduction, and that reduced coenzyme plays a noncovalent effector role in this substrate activating step. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0006-2960 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:238585 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3817 |
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| Author |
Dyson, H.J.; Beattie, J.K. |
| Title |
Spin state and unfolding equilibria of ferricytochrome c in acidic solutions |
Type |
Journal Article |
| Year |
1982 |
Publication |
The Journal of Biological Chemistry |
Abbreviated Journal |
J Biol Chem |
| Volume |
257 |
Issue |
5 |
Pages |
2267-2273 |
| Keywords |
Animals; *Cytochrome c Group; Electron Spin Resonance Spectroscopy; Heme; Horses; Hydrogen-Ion Concentration; Kinetics; Ligands; Myocardium; Protein Binding; Protein Conformation; Spectrophotometry; Temperature |
| Abstract |
Equilibrium, stopped flow, and temperature-jump spectrophotometry have been used to identify processes in the unfolding of ferricytochrome c in acidic aqueous solutions. A relaxation occurring in approximately 100 microseconds involves perturbation of a spin-equilibrium between two folded conformers of the protein with methionine-80 coordinated or dissociated from the heme iron. The protein unfolds more slowly, in milliseconds, with dissociation and protonation of histidine-18. These two transitions appear cooperative in equilibrium measurements at low (0.01 M) ionic strength, but are separated at higher (0.10 M) ionic strength. They are resolved under both conditions in the dynamic measurements. The spin-equilibrium description permits a unified explanation of a number of properties of ferricytochrome c in acidic aqueous solutions. |
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Thesis |
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Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0021-9258 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:6277891 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3807 |
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| Author |
Hasumi, H. |
| Title |
Kinetic studies on isomerization of ferricytochrome c in alkaline and acid pH ranges by the circular dichroism stopped-flow method |
Type |
Journal Article |
| Year |
1980 |
Publication |
Biochimica et Biophysica Acta |
Abbreviated Journal |
Biochim Biophys Acta |
| Volume |
626 |
Issue |
2 |
Pages |
265-276 |
| Keywords |
Circular Dichroism; *Cytochrome c Group; Hydrogen-Ion Concentration; Isomerism; Kinetics; Spectrophotometry |
| Abstract |
The isomerization of horse-heart ferricytochrome c caused by varying pH was kinetically studied by using circular dichroism (CD) and optical absorption stopped-flow techniques. In the pH range of 7--13, the existence of the three different forms of ferricytochrome c (pH less than 10, pH 10--12, and pH greater than 12) was indicated from the statistical difference CD spectra. On the basis of analyses of the stopped-flow traces in the near-ultraviolet and Soret wavelength regions, the isomerization of ferricytochrome c from neutral form to the above three alkaline forms was interpreted as follows (1) below pH 10, the replacement of the intrinsic ligand of methionine residue by lysine residue occurs; (2) between pH 10 and 12, the uncoupling of the polypeptide chain from close proximity of the heme group occurs first, followed by the interconversion of the intrinsic ligands; and (3) above pH 12, hydroxide form of ferricytochrome c is formed, though the replacement of the intrinsic ligand by extrinsic ligands may occur via different routes from those below pH 12. The CD changes at 288 nm and in the Soret region caused by the pH-jump (down) from pH 6.0 to 1.6 were compared with the appearance of the 620-nm absorption band ascribed to the formation of the high-spin form of ferricytochrome c. Both CD and absorption changes indicated that the isomerization at pH 1.6 consisted of two processes: one proceeded within the dead-time (about 2 ms) of the stopped-flow apparatus and the other proceeded at a determinable rate with the apparatus. On the basis of these results, the isomerization of ferricytochrome c at pH 1.6 was explained as follows: (1) the transition from the low-spin form to the high-spin forms occurs within about 2 ms, the dead-time of the stopped-flow apparatus; and (2) the polypeptide chain is unfolded after the formation of the high-spin form. |
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Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0006-3002 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:6260152 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
3876 |
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| Author |
Hirota, S.; Suzuki, M.; Watanabe, Y. |
| Title |
Hydrophobic effect of trityrosine on heme ligand exchange during folding of cytochrome c |
Type |
Journal Article |
| Year |
2004 |
Publication |
Biochemical and Biophysical Research Communications |
Abbreviated Journal |
Biochem Biophys Res Commun |
| Volume |
314 |
Issue |
2 |
Pages |
452-458 |
| Keywords |
Amino Acids/chemistry; Animals; Cytochromes c/*chemistry; Heme/*chemistry; Histidine/chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Ligands; Myocardium/chemistry; Peptides/chemistry; Protein Folding; Spectrophotometry; Spectrum Analysis, Raman; Tyrosine/*analogs & derivatives/*chemistry |
| Abstract |
Effect of a hydrophobic peptide on folding of oxidized cytochrome c (cyt c) is studied with trityrosine. Folding of cyt c was initiated by pH jump from 2.3 (acid-unfolded) to 4.2 (folded). The Soret band of the 2-ms transient absorption spectrum during folding decreased its intensity and red-shifted from 397 to 400 nm by interaction with trityrosine, whereas tyrosinol caused no significant effect. The change in the transient absorption spectrum by interaction with trityrosine was similar to that obtained with 100 mM imidazole, which showed that the population of the intermediate His/His coordinated species increased during folding of cyt c by interaction with trityrosine. The absorption change was biphasic, the fast phase (82+/-9s(-1)) corresponding to the transition from the His/H(2)O to the His/Met coordinated species, whereas the slow phase (24+/-3s(-1)) from His/His to His/Met. By addition of trityrosine, the relative ratio of the slow phase increased, due to increase of the His/His species at the initial stage of folding. According to the resonance Raman spectra of cyt c, the high-spin 6-coordinate and low-spin 6-coordinate species were dominated at pH 2.3 and 4.2, respectively, and these species were not affected by addition of trityrosine. These results demonstrated that the His/His species increased by interaction with trityrosine at the initial stage of cyt c folding, whereas the heme coordination structure was not affected by trityrosine when the protein was completely unfolded or folded. Hydrophobic peptides thus may be useful to study the effects of hydrophobic interactions on protein folding. |
| Address |
Department of Physical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, 607-8414 Kyoto, Japan. hirota@mb.kyoto-phu.ac.jp |
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Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0006-291X |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:14733927 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3777 |
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| Author |
Jallon, J.M.; Risler, Y.; Iwatsubo, M. |
| Title |
Beef liver L-Glutamate dehydrogenase mechanism: presteady state study of the catalytic reduction of 2.oxoglutarate by NADPH |
Type |
Journal Article |
| Year |
1975 |
Publication |
Biochemical and biophysical research communications |
Abbreviated Journal |
Biochem Biophys Res Commun |
| Volume |
67 |
Issue |
4 |
Pages |
1527-1536 |
| Keywords |
Animals; Cattle; Glutamate Dehydrogenase/*metabolism; Ketoglutaric Acids; Kinetics; Liver/*enzymology; Nadp; Oxidation-Reduction; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet |
| Abstract |
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Thesis |
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Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0006-291X |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:1038 |
Approved |
no |
| Call Number |
Admin @ knut @ |
Serial |
21 |
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| Author |
Kihara, H.; Nakatani, H.; Hiromi, K.; Hon-Nami, K. |
| Title |
Kinetic studies on redox reactions of hemoproteins. I. Reduction of thermoresistant cytochrome c-552 and horse heart cytochrome c by ferrocyanide |
Type |
Journal Article |
| Year |
1977 |
Publication |
Biochimica et Biophysica Acta |
Abbreviated Journal |
Biochim Biophys Acta |
| Volume |
460 |
Issue |
3 |
Pages |
480-489 |
| Keywords |
Animals; Bacteria; *Cytochrome c Group; *Ferrocyanides; Horses; Kinetics; Mathematics; Oxidation-Reduction; Spectrophotometry; Spectrophotometry, Ultraviolet; Temperature; Thermodynamics |
| Abstract |
The oxidation-reduction reaction of horse heart cytochrome c and cytochrome c (552, Thermus thermophilus), which is highly thermoresistant, was studied by temperature-jump method. Ferrohexacyanide was used as reductant. (Formula: see text.) Thermodynamic and activation parameters of the reaction obtained for both cytochromes were compared with each other. The results of this showed that (1) the redox potential of cytochrome c-552, + 0.19 V, is markedly less than that of horse heart cytochrome c. (2) deltaHox of cytochrome c-552 is considerably lower than that of horse heart cytochrome c. (3) deltaSox and deltaSred of cytochrome c-552 are more negative than those of horse heart cytochrome c. (4) kred of cytochrome c-552 is much lower than that of horse heart cytochrome c at room temperature. |
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Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0006-3002 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:195599 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3815 |
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