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	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
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	Author	Saigo, S.
	Title	A transient spin-state change during alkaline isomerization of ferricytochrome c			Type	Journal Article
	Year	1981	Publication	Journal of Biochemistry	Abbreviated Journal	J Biochem (Tokyo)
	Volume	89	Issue	6	Pages	1977-1980
	Keywords	Animals; *Cytochrome c Group; Horses; Hydrogen-Ion Concentration; Isomerism; Kinetics; Myocardium/enzymology; Oxidation-Reduction; Spectrophotometry
	Abstract	Kinetic difference spectra during the alkaline isomerization of ferricytochrome c were obtained by the pH-jump method in the range of 540 to 655 nm. The spectrum of the transient intermediate, which appears during the course of the isomerization, was reproduced from the spectra. The intermediate showed an intense absorption band at 600 nm, indicating that it is a high spin or mixed spin species. This is in contrast to the stable neutral and alkaline forms which are low spin species. The transient spin-state change during the isomerization was also observed upon rapid oxidation of ferrocytochrome c at alkaline pH.
	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	0021-924X	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:6270075			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3808
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	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
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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.
	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
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	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
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	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
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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
	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
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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
	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
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	Author	Czerlinski, G.H.; Wagner, M.; Erickson, J.O.; Theorell, H.
	Title	Chemical relaxation studies on the system liver alcohol dehydrogenase, NADH and imidazole			Type	Journal Article
	Year	1975	Publication	Acta Chemica Scandinavica. Series B: Organic Chemistry and Biochemistry	Abbreviated Journal	Acta Chem Scand B
	Volume	29	Issue	8	Pages	797-810
	Keywords	Alcohol Oxidoreductases/metabolism; Animals; Computers; Hydrogen-Ion Concentration; Imidazoles/metabolism; Kinetics; Liver/enzymology/metabolism; Mathematics; Models, Chemical; NAD/metabolism; Time Factors
	Abstract	Several years ago, Theorell and Czerlinski conducted experiments on the system of horse liver alcohol dehydrogenase, reduced nicotinamide adenine dinucleotide and imidazole, using the first version of the temperature jump apparatus with detection of changes in fluorescence. These early experiments were repeated with improved instrumentation and confirmed the early experiments in general terms. However, the improved detection system allowed to measure a slight concentration dependence of the relaxation time of around 3 ms. Furthermore, the chemical relaxation time was smaller than the one determined earlier (by factor 2). The data were evaluated much more rigorously than before, allowing an appropriate interpretation of the results. The observed relaxation time is largely due to rate constants in an interconversion of ternary complexes, which are faster than three (of the four) dissociation rate constants, determined previously by Theorell and McKinley-McKee.1,2 This fact contributed to earlier difficulties of finding any concentration dependence. However, the binding of imidazole to the binary enzyme-coenzyme complex can be made to couple kinetically into the interconversion rate of the two ternary complexes. The observed signal derives largely from the ternary complex(es). A substantial fluorescence signal change is associated with the observed relaxation process, suggesting a relocation of the imidazole in reference to the nicotinamide moiety of the bound coenzyme. Nine models are considered with two types of coupling of pre-equilibria (none-all). Quantitative evaluations favor the model with two ternary complexes connected by an interconversion outside the four-step (bimolecular) cycle. The ternary complex outside the cycle has much higher fluorescence yield than the one inside. The interconversion equilibrium is near unity for imidazole. If it would be shifted very much to the side of the “dead-end” complex (as in isobutyramide?!), stimulating action could not take place.
	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	0302-4369	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:882			Approved	no
	Call Number	refbase @ user @			Serial	3887
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	Author	Galloux, P.; Barrey, E.
	Title	Components of the total kinetic moment in jumping horses			Type	Journal Article
	Year	1997	Publication	Equine Veterinary Journal. Supplement	Abbreviated Journal	Equine Vet J Suppl
	Volume		Issue	23	Pages	41-44
	Keywords	Algorithms; Animals; Exertion/physiology; Female; Gravitation; Horses/physiology; Kinetics; Locomotion/physiology; Male; Models, Biological; Movement/physiology; Video Recording
	Abstract	Thirty horses were filmed with a panning camera operating at 50 frames/s as they jumped over a 1.20 x 1.20 m fence. The markers of 9 joints on the horse and 7 joints on the rider were tracked in 2D with the TrackEye system. The centre of gravity and moment of inertia of each segment were calculated using a geometric algorithm and a cylindric model, respectively. The kinetic moment of each part of the horse was calculated after filtering, and resampling of data. This method showed the relative contribution of each body segment to the body overall rotation during the take-off, jump and landing phases. It was found that the trunk, hindlimbs and head-neck had the greatest influence. The coordination between the motion of the body segments allowed the horse to control its angular speed of rotation over the fence. This remained nearly constant during the airborne phase (120 +/- 5 degrees/s). During the airborne phase, the kinetic moment was constant because its value was equal to the moment of the external forces (722 +/- 125 kg x m2/s).
	Address	Ecole Nationale d'Equitation, Terrefort, Saumur, France
	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		ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:9354287			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3797
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