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Author |
Ryan, C.T.; Schaer, B.L.D.; Nunamaker, D.M. |
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Title |
A novel wireless data acquisition system for the measurement of hoof accelerations in the exercising horse |
Type |
Journal Article |
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Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
38 |
Issue |
7 |
Pages |
671-674 |
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Keywords  |
*Acceleration; Animals; Biomechanics; Equipment and Supplies/*veterinary; Hoof and Claw/*physiology; Horses/*physiology; Kinetics; Musculoskeletal Physiology; Physical Conditioning, Animal/*physiology; Running/physiology |
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Abstract |
REASONS FOR PERFORMING STUDY: A device is needed to safely and wirelessly evaluate accelerations experienced by the horse hoof under a variety of surface conditions with the horse exercising at training or racing speeds. OBJECTIVES: To develop a miniaturised wireless data acquisition system (WDAS) which reliably records hoof accelerations and the times over which they occur in a minimally invasive manner in the exercising Thoroughbred. METHODS: The following criteria were set for device development: production of a lightweight and minimally invasive system, which provides an adequate acceleration range, appropriate frequency response to capture high speed events, and compatibility with a low power wireless telemetry system. Following device development, the WDAS was calibrated, and tested in 6 Thoroughbred horses over a variety of surfaces. RESULTS: Collection of acceleration in seven trials using 6 horses over a variety of surfaces resulted in repeatable acceleration data with respect to the overall characteristic shape of the impact profile. Impact accelerations varied with surface, ranging 34.8-191.7 g. Accelerations on take off were in a similar range, although higher in some trials. Peak impact accelerations tended to larger over the grass paddock surface, than either the indoor arena or the dirt track. During dirt track trials, accelerations on take-off were often comparably larger than those observed on impact within the same footfall. CONCLUSIONS: This study reports the development of a wireless system that successfully measures hoof acceleration in a minimally invasive manner over a variety of surface and exercise conditions. POTENTIAL RELEVANCE: The WDAS will be used in further studies to evaluate various components of the horse-racetrack interface, in an attempt to identify risk factors for musculoskeletal injury in the Thoroughbred racehorse. |
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Richard S. Reynolds, Jr. Comparative Orthopedic Research Laboratory, Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania 19348, USA |
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0425-1644 |
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PMID:17228584 |
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no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
4023 |
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Author |
Dunn, M.F.; Branlant, G. |
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Title |
Roles of zinc ion and reduced coenzyme in horse liver alcohol dehydrogenase catalysis. The mechanism of aldehyde activation |
Type |
Journal Article |
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Year |
1975 |
Publication |
Biochemistry |
Abbreviated Journal |
Biochemistry |
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Volume |
14 |
Issue |
14 |
Pages |
3176-3182 |
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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 |
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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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0006-2960 |
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Notes |
PMID:238585 |
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no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
3817 |
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Author |
Bayley, P.; Martin, S.; Anson, M. |
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Title |
Temperature-jump circular dichroism: observation of chiroptical relaxation processes at millisecond time resolution |
Type |
Journal Article |
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Year |
1975 |
Publication |
Biochemical and Biophysical Research Communications |
Abbreviated Journal |
Biochem Biophys Res Commun |
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Volume |
66 |
Issue |
1 |
Pages |
303-308 |
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Keywords |
*Alcohol Oxidoreductases/metabolism; Animals; Circular Dichroism; Horses; Kinetics; Liver/enzymology; Mathematics; Protein Conformation; Temperature; Time Factors |
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English |
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0006-291X |
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Notes |
PMID:1172440 |
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no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
3816 |
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Author |
Guo, G.L.; Moffit, J.S.; Nicol, C.J.; Ward, J.M.; Aleksunes, L.A.; Slitt, A.L.; Kliewer, S.A.; Manautou, J.E.; Gonzalez, F.J. |
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Title |
Enhanced acetaminophen toxicity by activation of the pregnane X receptor |
Type |
Journal Article |
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Year |
2004 |
Publication |
Toxicological sciences : an official journal of the Society of Toxicology |
Abbreviated Journal |
Toxicol Sci |
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Volume |
82 |
Issue |
2 |
Pages |
374-380 |
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Keywords |
Acetaminophen/pharmacokinetics/*toxicity; Analgesics, Non-Narcotic/pharmacokinetics/*toxicity; Animals; Aryl Hydrocarbon Hydroxylases/biosynthesis; Biotransformation; Blotting, Northern; Chromatography, High Pressure Liquid; Cytochrome P-450 CYP3A; Membrane Proteins; Mice; Mice, Knockout; Oxidoreductases, N-Demethylating/biosynthesis; Pregnenolone Carbonitrile/pharmacology; Receptors, Cytoplasmic and Nuclear/*drug effects; Receptors, Steroid/*drug effects; Sulfhydryl Compounds/metabolism |
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Abstract |
The pregnane X receptor (PXR) is a ligand-activated transcription factor and member of the nuclear receptor superfamily. Activation of PXR represents an important mechanism for the induction of cytochrome P450 3A (CYP3A) enzymes that can convert acetaminophen (APAP) to its toxic intermediate metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Therefore, it was hypothesized that activation of PXR plays a major role in APAP-induced hepatotoxicity. Pretreatment with the PXR activator, pregnenolone 16alpha-carbonitrile (PCN), markedly enhanced APAP-induced hepatic injury, as revealed by increased serum ALT levels and hepatic centrilobular necrosis, in wild-type but not in PXR-null mice. Further analysis showed that following PCN treatment, PXR-null mice had lower CYP3A11 expression, decreased NAPQI formation, and increased maintenance of hepatic glutathione content compared to wild-type mice. Thus, these results suggest that PXR plays a critical role in APAP-induced hepatic toxicity, probably by inducing CYP3A11 expression and hence increasing bioactivation. |
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Laboratory of Metabolism, CCR, NCI, NIH, Bethesda, Maryland 20892, USA |
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English |
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Abbreviated Series Title |
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ISSN |
1096-6080 |
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Notes |
PMID:15456926 |
Approved |
no |
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Call Number |
refbase @ user @ |
Serial |
71 |
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Author |
Dirikolu, L.; Lehner, A.F.; Karpiesiuk, W.; Hughes, C.; Woods, W.E.; Boyles, J.; Harkins, J.D.; Troppmann, A.; Tobin, T. |
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Title |
Detection, quantification, metabolism, and behavioral effects of selegiline in horses |
Type |
Journal Article |
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Year |
2003 |
Publication |
Veterinary Therapeutics : Research in Applied Veterinary Medicine |
Abbreviated Journal |
Vet Ther |
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Volume |
4 |
Issue |
3 |
Pages |
257-268 |
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Keywords |
Administration, Oral; Animals; Behavior, Animal/drug effects; Female; Horses/*metabolism; Mass Spectrometry/veterinary; Monoamine Oxidase Inhibitors/administration & dosage/blood/*pharmacokinetics/pharmacology/urine; Selegiline/administration & dosage/blood/*pharmacokinetics/pharmacology/urine; Substance Abuse Detection/veterinary |
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Abstract |
Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates. |
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Address |
Department of Biomedical Sciences, College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA |
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English |
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ISSN |
1528-3593 |
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Notes |
PMID:15136987 |
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no |
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Call Number |
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Serial |
1901 |
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Author |
Machnik, M.; Hegger, I.; Kietzmann, M.; Thevis, M.; Guddat, S.; Schanzer, W. |
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Title |
Pharmacokinetics of altrenogest in horses |
Type |
Journal Article |
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Year |
2007 |
Publication |
Journal of Veterinary Pharmacology and Therapeutics |
Abbreviated Journal |
J Vet Pharmacol Ther |
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Volume |
30 |
Issue |
1 |
Pages |
86-90 |
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Keywords |
Administration, Oral; Animals; Chromatography, Liquid/veterinary; Doping in Sports/prevention & control; Horses/*metabolism; Male; Mass Spectrometry/veterinary; Progesterone Congeners/administration & dosage/blood/*pharmacokinetics/urine; Reproducibility of Results; Substance Abuse Detection/veterinary; Trenbolone/administration & dosage/*analogs & derivatives/blood/pharmacokinetics/urine |
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Abstract |
The Federation Equestre Internationale has permitted the use of altrenogest in mares for the control of oestrus. However, altrenogest is also suspicious to misuse in competition horses for its potential anabolic effects and suppression of typical male behaviour, and thus is a controlled drug. To investigate the pharmacokinetics of altrenogest in horses we conducted an elimination study. Five oral doses of 44 mug/kg altrenogest were administered to 10 horses at a dose interval of 24 h. Following administration blood and urine samples were collected at appropriate intervals. Altrenogest concentrations were measured by liquid chromatography-tandem mass spectrometry. The plasma levels of altrenogest reached maximal concentrations of 23-75 ng/mL. Baseline values were achieved within 3 days after the final administration. Urine peak concentrations of total altrenogest ranged from 823 to 3895 ng/mL. Twelve days after the final administration concentrations were below the limit of detection (ca 2 ng/mL). |
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Address |
Institute of Biochemistry, German Sport University, Cologne, Germany. m.machnik@biochem.dshs-koeln.de |
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ISSN |
0140-7783 |
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Notes |
PMID:17217407 |
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no |
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Call Number |
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Serial |
1841 |
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Author |
Andersson, P.; Kvassman, J.; Lindstrom, A.; Olden, B.; Pettersson, G. |
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Title |
Effect of NADH on the pKa of zinc-bound water in liver alcohol dehydrogenase |
Type |
Journal Article |
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Year |
1981 |
Publication |
European Journal of Biochemistry / FEBS |
Abbreviated Journal |
Eur J Biochem |
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Volume |
113 |
Issue |
3 |
Pages |
425-433 |
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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 |
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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. |
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English |
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ISSN |
0014-2956 |
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Notes |
PMID:7011796 |
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no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
3810 |
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Author |
Czerlinski, G.H.; Wagner, M.; Erickson, J.O.; Theorell, H. |
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Title |
Chemical relaxation studies on the system liver alcohol dehydrogenase, NADH and imidazole |
Type |
Journal Article |
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Year |
1975 |
Publication |
Acta Chemica Scandinavica. Series B: Organic Chemistry and Biochemistry |
Abbreviated Journal |
Acta Chem Scand B |
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Volume |
29 |
Issue |
8 |
Pages |
797-810 |
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Keywords |
Alcohol Oxidoreductases/*metabolism; Animals; Computers; Hydrogen-Ion Concentration; Imidazoles/*metabolism; Kinetics; Liver/enzymology/*metabolism; Mathematics; Models, Chemical; NAD/*metabolism; Time Factors |
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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. |
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0302-4369 |
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Notes |
PMID:882 |
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Call Number |
refbase @ user @ |
Serial |
3887 |
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Author |
Galloux, P.; Barrey, E. |
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Title |
Components of the total kinetic moment in jumping horses |
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Journal Article |
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Year |
1997 |
Publication |
Equine Veterinary Journal. Supplement |
Abbreviated Journal |
Equine Vet J Suppl |
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Volume |
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Issue |
23 |
Pages |
41-44 |
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Keywords |
Algorithms; Animals; Exertion/*physiology; Female; Gravitation; Horses/*physiology; Kinetics; Locomotion/*physiology; Male; Models, Biological; Movement/*physiology; Video Recording |
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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). |
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Address |
Ecole Nationale d'Equitation, Terrefort, Saumur, France |
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English |
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Notes |
PMID:9354287 |
Approved |
no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
3797 |
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Author |
Pierce, M.M.; Nall, B.T. |
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Title |
Coupled kinetic traps in cytochrome c folding: His-heme misligation and proline isomerization |
Type |
Journal Article |
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Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
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Volume |
298 |
Issue |
5 |
Pages |
955-969 |
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Keywords |
Amino Acid Sequence; Amino Acid Substitution/genetics; Binding Sites; Cytochrome c Group/*chemistry/genetics/*metabolism; *Cytochromes c; Enzyme Stability/drug effects; Fluorescence; Guanidine/pharmacology; Heme/*metabolism; Histidine/genetics/*metabolism; Hydrogen-Ion Concentration; Isomerism; Kinetics; Models, Molecular; Molecular Sequence Data; Mutation/genetics; Proline/*chemistry/metabolism; Protein Conformation/drug effects; Protein Denaturation/drug effects; *Protein Folding; Protein Renaturation; Saccharomyces cerevisiae/enzymology/genetics; Sequence Alignment; Thermodynamics |
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Abstract |
The effect of His-heme misligation on folding has been investigated for a triple mutant of yeast iso-2 cytochrome c (N26H,H33N,H39K iso-2). The variant contains a single misligating His residue at position 26, a location at which His residues are found in several cytochrome c homologues, including horse, tuna, and yeast iso-1. The amplitude for fast phase folding exhibits a strong initial pH dependence. For GdnHCl unfolded protein at an initial pH<5, the observed refolding at final pH 6 is dominated by a fast phase (tau(2f)=20 ms, alpha(2f)=90 %) that represents folding in the absence of misligation. For unfolded protein at initial pH 6, folding at final pH 6 occurs in a fast phase of reduced amplitude (alpha(2f) approximately 20 %) but the same rate (tau(2f)=20 ms), and in two slower phases (tau(m)=6-8 seconds, alpha(m) approximately 45 %; and tau(1b)=16-20 seconds, alpha(1b) approximately 35 %). Double jump experiments show that the initial pH dependence of the folding amplitudes results from a slow pH-dependent equilibrium between fast and slow folding species present in the unfolded protein. The slow equilibrium arises from coupling of the His protonation equilibrium to His-heme misligation and proline isomerization. Specifically, Pro25 is predominantly in trans in the unligated low-pH unfolded protein, but is constrained in a non-native cis isomerization state by His26-heme misligation near neutral pH. Refolding from the misligated unfolded form proceeds slowly due to the large energetic barrier required for proline isomerization and displacement of the misligated His26-heme ligand. |
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Center for Biomolecular Structure, Department of Biochemistry, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA |
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English |
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0022-2836 |
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PMID:10801361 |
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refbase @ user @ |
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3853 |
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