| |
Records |
Links |
|
Author |
Ridge, J.A.; Baldwin, R.L.; Labhardt, A.M. |
|
| |
Title |
Nature of the fast and slow refolding reactions of iron(III) cytochrome c |
Type |
Journal Article |
| |
Year  |
1981 |
Publication |
Biochemistry |
Abbreviated Journal |
Biochemistry |
|
| |
Volume |
20 |
Issue |
6 |
Pages |
1622-1630 |
|
| |
Keywords |
Animals; Ascorbic Acid; *Cytochrome c Group; Guanidines; Horses; Kinetics; Oxidation-Reduction; Protein Conformation; Spectrum Analysis |
|
| |
Abstract |
The fast and slow refolding reactions of iron(III) cytochrome c (Fe(III) cyt c), previously studied by Ikai et al. (Ikai, A., Fish, W. W., & Tanford, C. (1973) J. Mol. Biol. 73, 165--184), have been reinvestigated. The fast reaction has the major amplitude (78%) and is 100-fold faster than the slow reaction in these conditions (pH 7.2, 25 degrees C, 1.75 M guanidine hydrochloride). We show here that native cyt c is the product formed in the fast reaction as well as in the slow reaction. Two probes have been used to test for formation of native cyt c. absorbance in the 695-nm band and rate of reduction of by L-ascorbate. Different unfolded species (UF, US) give rise to the fast and slow refolding reactions, as shown both by refolding assays at different times after unfolding (“double-jump” experiments) and by the formation of native cyt c in each of the fast and slow refolding reactions. Thus the fast refolding reaction is UF leads to N and the slow refolding reaction is Us leads to N, where N is native cyt c, and there is a US in equilibrium UF equilibrium in unfolded cyt c. The results are consistent with the UF in equilibrium US reaction being proline isomerization, but this has not yet been tested in detail. Folding intermediates have been detected in both reactions. In the UF leads to N reaction, the Soret absorbance change precedes the recovery of the native 695-nm band spectrum, showing that Soret absorbance monitors the formation of a folding intermediate. In the US leads to N reaction an ascorbate-reducible intermediate has been found at an early stage in folding and the Soret absorbance change occurs together with the change at 695 nm as N is formed in the final stage of folding. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-2960 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:6261802 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3809 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Andersson, P.; Kvassman, J.; Lindstrom, A.; Olden, B.; Pettersson, G. |
|
| |
Title |
Effect of NADH on the pKa of zinc-bound water in liver alcohol dehydrogenase |
Type |
Journal Article |
| |
Year |
1981 |
Publication |
European Journal of Biochemistry / FEBS |
Abbreviated Journal |
Eur J Biochem |
|
| |
Volume |
113 |
Issue |
3 |
Pages |
425-433 |
|
| |
Keywords |
Alcohol Oxidoreductases/*metabolism; Aldehydes/metabolism; Animals; Binding Sites; Cinnamates/metabolism; Horses; Hydrogen-Ion Concentration; Kinetics; Ligands; Liver/*metabolism; NAD/*metabolism; Water/metabolism; Zinc/metabolism |
|
| |
Abstract |
Equilibrium constants for coenzyme binding to liver alcohol dehydrogenase have been determined over the pH range 10--12 by pH-jump stop-flow techniques. The binding of NADH or NAD+ requires the protonated form of an ionizing group (distinct from zinc-bound water) with a pKa of 10.4. Complex formation with NADH exhibits an additional dependence on the protonation state of an ionizing group with a pKa of 11.2. The binding of trans-N,N-dimethylaminocinnamaldehyde to the enzyme . NADH complex is prevented by ionization of the latter group. It is concluded from these results that the pKa-11.2-dependence of NADH binding most likely derives from ionization of the water molecule bound at the catalytic zinc ion of the enzyme subunit. The pKa value of 11.2 thus assigned to zinc-bound water in the enzyme . NADH complex appears to be typical for an aquo ligand in the inner-sphere ligand field provided by the zinc-binding amino acid residues in liver alcohol dehydrogenase. This means that the pKa of metal-bound water in zinc-containing enzymes can be assumed to correlate primarily with the number of negatively charged protein ligands coordinated by the active-site zinc ion. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0014-2956 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:7011796 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3810 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Saigo, S. |
|
| |
Title |
Kinetic and equilibrium studies of alkaline isomerization of vertebrate cytochromes c |
Type |
Journal Article |
| |
Year |
1981 |
Publication |
Biochimica et Biophysica Acta |
Abbreviated Journal |
Biochim Biophys Acta |
|
| |
Volume |
669 |
Issue |
1 |
Pages |
13-20 |
|
| |
Keywords |
Amino Acid Sequence; Animals; Cytochrome c Group/*metabolism; Dogs; Hydrogen-Ion Concentration; Isomerism; Kinetics; Vertebrates/metabolism |
|
| |
Abstract |
Equilibria and kinetics of alkaline isomerization of seven ferricytochromes c from vertebrates were studied by pH-titration and pH-jump methods in the pH region of 7-12. In the equilibrium behavior, no significant difference was detected among the cytochromes c, whereas marked differences in the kinetic behavior were observed. According to the kinetic behavior of the isomerization, the cytochromes c examined fall into three classes: Group I (horse, sheep, dog and pigeon cytochromes c), Group II (tuna and bonito cytochromes c) and Group III (rhesus monkey cytochrome c). The kinetic results are interpreted in terms of the sequential scheme: Neutral form in equilibrium with fast Transient form in equilibrium with slow Alkaline form where the neutral and alkaline forms are the species stable at neutral and alkaline pH, respectively, and the transient form is a kinetic intermediate. From comparison of the primary sequences of the seven cytochromes c and the classification of these cytochromes c, it is concluded that the amino acid substitution Phe/Tyr at the 46-th position has a major influence on the kinetic behavior. In Group II and III cytochromes c, the ionization of Tyr-46 is suggested to bring about loosening of the heme crevice and thus facilitate the ligand replacement involved in the isomerization. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-3002 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:6271238 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3871 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gonzalez-Fernandez, J.M.; Atta, S.E. |
|
| |
Title |
Facilitated transport of oxygen in the presence of membranes in the diffusion path |
Type |
Journal Article |
| |
Year |
1982 |
Publication |
Biophysical Journal |
Abbreviated Journal |
Biophys J |
|
| |
Volume |
38 |
Issue |
2 |
Pages |
133-141 |
|
| |
Keywords |
Animals; Biological Transport, Active; Cell Membrane/*metabolism; Diffusion; Dogs; Horses; Humans; Kinetics; Mathematics; *Models, Biological; Muscles/*metabolism; Oxygen/*metabolism |
|
| |
Abstract |
Most of the experimental observations on facilitated transport have been done with millipore filters, and all the theoretical studies have assumed homogeneous spatial properties. In striated muscle there exist membranes that may impede the diffusion of the carrier myoglobin. In this paper a theoretical study is undertaken to analyze the transport in the presence of membranes in the diffusion path. For the numerical computations physiologically relevant values of the parameters were chosen. The numerical results indicate that the presence of membranes tends to decrease the facilitation. For the nonlinear chemical kinetics of the reaction of oxygen with the carrier, this decrement also depends on the location of the membranes. At the higher oxygen concentration side of each membrane the flow of combined oxygen is transferred to the flow of dissolved oxygen. The reverse process occurs at the lower concentration side. Jump discontinuities of the concentration of the oxygen-carrier compound at each membrane are associated with these transfers. The decrement of facilitation is due to the cumulative effect of these jump discontinuities. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-3495 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:7093418 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3806 |
|
| Permanent link to this record |
| |
|
| |
|
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. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-9258 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:6277891 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3807 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cho, K.C.; Chan, K.K. |
|
| |
Title |
Kinetics of cold-induced denaturation of metmyoglobin |
Type |
Journal Article |
| |
Year |
1984 |
Publication |
Biochimica et Biophysica Acta (BBA) – Protein Structure and Molecular Enzymology |
Abbreviated Journal |
|
|
| |
Volume |
786 |
Issue |
1-2 |
Pages |
103-108 |
|
| |
Keywords |
Metmyoglobin denaturation; Temperature jump; Denaturation kinetics; Conformational transformation; (Horse heart) |
|
| |
Abstract |
Using a slow temperature-jump spectrophotometer, we have studied the kinetics of cold-induced denaturation of metmyoglobin between 0[degree sign]C and 20[degree sign]C at acidic pH. The time-scale of the transition is slow and is of the order of minutes. The results are consistent with the transition's involving a total of three states, native (N), transient intermediate (I) and denatured (D), which are converted from one to the other in that order. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3978 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sukhomlinov, B.F.; Korobov, V.N.; Gonchar, M.V.; Datsiuk, L.A.; Korzhev, V.A. |
|
| |
Title |
[Comparative analysis of the peroxidase activity of myoglobins in mammals] |
Type |
Journal Article |
| |
Year |
1987 |
Publication |
Zhurnal Evoliutsionnoi Biokhimii i Fiziologii |
Abbreviated Journal |
Zh Evol Biokhim Fiziol |
|
| |
Volume |
23 |
Issue |
1 |
Pages |
37-41 |
|
| |
Keywords |
Amino Acid Sequence; Animals; Ecology; *Evolution; Kinetics; Mammals/*metabolism; Myoglobin/*metabolism; Peroxidases/*metabolism |
|
| |
Abstract |
Studies have been made on the peroxidase activity of metmyoglobins in animals from various ecological groups--the horse Equus caballus, cattle Bos taurus, beaver Castor fiber, otter Lutra lutra, mink Mustela vison and dog Canis familiaris. It was found that the level of this activity in diving animals depends on the duration of their diving, whereas in terrestrial species--on the strength of muscular contraction. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
Russian |
Summary Language |
|
Original Title |
Sravnitel'nyi analiz peroksidaznoi aktivnosti mioglobinov u mlekopitaiushchikh |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0044-4529 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:3564776 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
2681 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Steinhoff, H.J.; Schrader, J.; Schlitter, J. |
|
| |
Title |
Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals |
Type |
Journal Article |
| |
Year |
1992 |
Publication |
Biochimica et Biophysica Acta |
Abbreviated Journal |
Biochim Biophys Acta |
|
| |
Volume |
1121 |
Issue |
3 |
Pages |
269-278 |
|
| |
Keywords |
Animals; Crystallization; Horses; Kinetics; Methemoglobin/*chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/*chemistry |
|
| |
Abstract |
Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed. |
|
| |
Address |
Institut fur Biophysik, Ruhr-Universitat Bochum, Germany |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-3002 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:1627604 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3800 |
|
| Permanent link to this record |
| |
|
| |
|
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 |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0887-3585 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:8090705 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3799 |
|
| Permanent link to this record |
| |
|
| |
|
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 |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0027-8424 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:8650166 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3798 |
|
| Permanent link to this record |
