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Author (up) 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 (up) Dyer, F.C.
Title Animal behaviour: when it pays to waggle Type
Year 2002 Publication Nature Abbreviated Journal Nature
Volume 419 Issue 6910 Pages 885-886
Keywords *Animal Communication; Animals; Bees/*physiology; California; Dancing/physiology; Environment; Evolution; Female; Flowers/chemistry; *Food; Gravitation; Lighting; Motor Activity/*physiology; Odors; Seasons; Sunlight
Abstract
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 0028-0836 ISBN Medium
Area Expedition Conference
Notes PMID:12410290 Approved no
Call Number refbase @ user @ Serial 769
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Author (up) Elsaesser, F.; Klobasa, F.; Ellendorff, F.
Title ACTH stimulation test for the determination of salivary cortisol and of cortisol responses as markers of the training status/fitness of warm-blooded sports horses] Type Journal Article
Year 2001 Publication DTW. Deutsche Tierarztliche Wochenschrift Abbreviated Journal Dtsch Tierarztl Wochenschr
Volume 108 Issue 1 Pages 31-36
Keywords Adrenocorticotropic Hormone/*diagnostic use; Animals; Health; Horses/*physiology; Hydrocortisone/*analysis/*secretion; Male; Orchiectomy; *Physical Conditioning, Animal; Running; Saliva/*chemistry; Walking
Abstract Previous work (Marc et al., 2000) suggested that plasma cortisol responses to treadmill exercise or ACTH injection are a reliable marker for performance evaluation in warmblood horses. For practical purposes blood sample collections and treadmill exercise tests are somewhat troublesome and time consuming. The goal of this study was thus to evaluate the use of saliva for cortisol determination (by direct EIA) as a marker for performance and to investigate the reliability and repeatability of plasma cortisol responses to a single i.v. injection of ACTH (50 micrograms or 250 micrograms). Furthermore, the effect of training horses for 8 weeks 3 times per week covering the same distance (increasing from 3.5 km during the first week to 8 km during the last week) either by trotting (approximately 240 m/min) or by cantering (375 m/min) was investigated. For this purpose initially ten four-year-old Hannovarian geldings, all reared in the same State stud, were used. Mean overall correlation between salivary cortisol and plasma cortisol concentrations was 0.64 when samples of various points of time were used. However, in spite of attempts to standardize saliva sample collection, correlation between salivary cortisol levels and plasma cortisol levels at distinct points of time in different tests were low and significant (r = 0.85, p < 0.02) only in one test. Thus, salivary cortisol measurements for diagnostic purposes are not reliable or useful. The repeatability of plasma cortisol responses to ACTH for untrained and trained horses were r = 0.86 and r = 0.8 respectively (p < or = 0.01 and p < or = 0.05 respectively). Training horses either by trotting or cantering did not affect the cortisol response either to treadmill exercise or to stimulation by ACTH. It is concluded that the relationship between salivary cortisol levels and plasma cortisol levels is not close enough to allow the use of salivary cortisol determination as marker of the training status/fitness of horses. The repeatability of the cortisol response to ACTH is similar to the cortisol response to treadmill exercise. Based on plasma cortisol responses to ACTH or treadmill exercise training horses by cantering at low speed is not superior to training by trotting for the fitness of horses.
Address Institut fur Tierzucht und Tierverhalten Mariensee (FAL), Holtystrasse 10, 31535 Neustadt. elsaesser@tzv.fal.de
Corporate Author Thesis
Publisher Place of Publication Editor
Language German Summary Language Original Title ACTH Stimulationstest und Bestimmung von Cortisol im Blut und Speichel zur Bewertung des Trainingszustands/der Kondition beim Warmblutpferd
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0341-6593 ISBN Medium
Area Expedition Conference
Notes PMID:11232423 Approved no
Call Number Equine Behaviour @ team @ Serial 4053
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Author (up) Franceschini, C.; Siutz, C.; Palme, R.; Millesi, E.
Title Seasonal changes in cortisol and progesterone secretion in Common hamsters Type Journal Article
Year 2007 Publication General and Comparative Endocrinology Abbreviated Journal Gen Comp Endocrinol
Volume 152 Issue 1 Pages 14-21
Keywords Animals; Cortisone/*secretion; Cricetinae/*metabolism; Feces/chemistry; Female; Lactation/physiology; Male; Pregnancy; Progesterone/*secretion; Reproduction/physiology; *Seasons; Sexual Behavior, Animal/physiology
Abstract In this study, we investigated endocrine factors and behaviour in free-living Common hamsters (Cricetus cricetus) during reproductive and non-reproductive periods of the annual cycle. We applied a non-invasive method to gain information on seasonal changes in adrenocortical activity in male and female hamsters by analysing faecal glucocorticoid metabolite concentrations (FCM). In addition, plasma progesterone concentrations were monitored in females throughout the non-hibernation season. The animals were live-trapped from spring emergence until the onset of hibernation in autumn. Reproductive status was determined at capture and blood and faecal samples were collected. During behavioural observations, agonistic and sexual interactions were recorded. FCM concentrations were significantly higher in males than in females during the reproductive period. In males, a pronounced increase in FCM during the reproductive period coincided with high frequencies of intrasexual aggression. In females, FCM levels remained relatively constant. Aggressive behaviour in females increased during the reproductive period, but was much less frequent than in males. Females, which successfully raised a second litter after a postpartum oestrus and concurrent lactation and gestation had lower FCM levels than individuals, which lost their second litter after parturition. As expected, plasma progesterone concentrations were low before and after the reproductive period. During gestation, levels peaked and remained elevated during lactation. The results of this field study provide insight in critical periods associated with reproduction in male and female Common hamsters.
Address Department of Behavioural Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria. claudia.franceschini@univie.ac.ct
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 0016-6480 ISBN Medium
Area Expedition Conference
Notes PMID:17408667 Approved no
Call Number Equine Behaviour @ team @ Serial 4076
Permanent link to this record
 
 
Author (up) Ganswindt, A.; Palme, R.; Heistermann, M.; Borragan, S.; Hodges, J.K.
Title Non-invasive assessment of adrenocortical function in the male African elephant (Loxodonta africana) and its relation to musth Type Journal Article
Year 2003 Publication General and Comparative Endocrinology Abbreviated Journal Gen Comp Endocrinol
Volume 134 Issue 2 Pages 156-166
Keywords Adrenal Cortex/*metabolism/secretion; Adrenal Cortex Function Tests/methods/*veterinary; Adrenocorticotropic Hormone/physiology; Animals; Carbon Isotopes/diagnostic use; Chromatography, High Pressure Liquid/veterinary; Elephants/*metabolism/urine; Feces/*chemistry; Glucocorticoids/analysis/urine; Hydrocortisone/*analysis/diagnostic use/urine; Immunoenzyme Techniques/methods/veterinary; Male; Reproduction/physiology; Sexual Behavior, Animal/physiology; Stress, Psychological/diagnosis/*physiopathology; Testosterone/*analysis/diagnostic use/urine
Abstract Adult male elephants periodically show the phenomenon of musth, a condition associated with increased aggressiveness, restlessness, significant weight reduction and markedly elevated androgen levels. It has been suggested that musth-related behaviours are costly and that therefore musth may represent a form of physiological stress. In order to provide data on this largely unanswered question, the first aim of this study was to evaluate different assays for non-invasive assessment of adrenocortical function in the male African elephant by (i) characterizing the metabolism and excretion of [3H]cortisol (3H-C) and [14C]testosterone (14C-T) and (ii) using this information to evaluate the specificity of four antibodies for determination of excreted cortisol metabolites, particularly with respect to possible cross-reactions with androgen metabolites, and to assess their biological validity using an ACTH challenge test. Based on the methodology established, the second objective was to provide data on fecal cortisol metabolite concentrations in bulls during the musth and non-musth condition. 3H-C (1 mCi) and 14C-T (100 microCi) were injected simultaneously into a 16 year old male and all urine and feces collected for 30 and 86 h, respectively. The majority (82%) of cortisol metabolites was excreted into the urine, whereas testosterone metabolites were mainly (57%) excreted into the feces. Almost all radioactive metabolites recovered from urine were conjugated (86% 3H-C and 97% 14C-T). In contrast, 86% and >99% of the 3H-C and 14C-T metabolites recovered from feces consisted of unconjugated forms. HPLC separations indicated the presence of various metabolites of cortisol in both urine and feces, with cortisol being abundant in hydrolysed urine, but virtually absent in feces. Although all antibodies measured substantial amounts of immunoreactivity after HPLC separation of peak radioactive samples and detected an increase in glucocorticoid output following the ACTH challenge, only two (in feces against 3alpha,11-oxo-cortisol metabolites, measured by an 11-oxo-etiocholanolone-EIA and in urine against cortisol, measured by a cortisol-EIA) did not show substantial cross-reactivity with excreted 14C-T metabolites and could provide an acceptable degree of specificity for reliable assessment of glucocorticoid output from urine and feces. Based on these findings, concentrations of immunoreactive 3alpha,11-oxo-cortisol metabolites were determined in weekly fecal samples collected from four adult bulls over periods of 11-20 months to examine whether musth is associated with increased adrenal activity. Results showed that in each male levels of these cortisol metabolites were not elevated during periods of musth, suggesting that in the African elephant musth is generally not associated with marked elevations in glucocorticoid output. Given the complex nature of musth and the variety of factors that are likely to influence its manifestation, it is clear, however, that further studies, particularly on free-ranging animals, are needed before a possible relationship between musth and adrenal function can be resolved. This study also clearly illustrates the potential problems associated with cross-reacting metabolites of gonadal steroids in EIAs measuring glucocorticoid metabolites. This has to be taken into account when selecting assays and interpreting results of glucocorticoid metabolite analysis, not only for studies in the elephant but also in other species.
Address German Primate Centre, Department of Reproductive Biology, Kellnerweg 4, 37077 Gottingen, Germany. ganswindt@www.dpz.gdwg.de
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 0016-6480 ISBN Medium
Area Expedition Conference
Notes PMID:14511986 Approved no
Call Number Equine Behaviour @ team @ Serial 4085
Permanent link to this record
 
 
Author (up) Gilmanshin, R.; Callender, R.H.; Dyer, R.B.
Title The core of apomyoglobin E-form folds at the diffusion limit Type Journal Article
Year 1998 Publication Nature Structural Biology Abbreviated Journal Nat Struct Biol
Volume 5 Issue 5 Pages 363-365
Keywords Animals; Apoproteins/*chemistry; Diffusion; Horses; Myoglobin/*chemistry; *Protein Folding; Spectroscopy, Fourier Transform Infrared; Temperature
Abstract The E-form of apomyoglobin has been characterized using infrared and fluorescence spectroscopies, revealing a compact core with native like contacts, most probably consisting of 15-20 residues of the A, G and H helices of apomyoglobin. Fast temperature-jump, time-resolved infrared measurements reveal that the core is formed within 96 micros at 46 degrees C, close to the diffusion limit for loop formation. Remarkably, the folding pathway of the E-form is such that the formation of a limited number of native-like contacts is not rate limiting, or that the contacts form on the same time scale expected for diffusion controlled loop formation.
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 1072-8368 ISBN Medium
Area Expedition Conference
Notes PMID:9586997 Approved no
Call Number Equine Behaviour @ team @ Serial 3795
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Author (up) Griffin, B.
Title The use of fecal markers to facilitate sample collection in group-housed cats Type Journal Article
Year 2002 Publication Contemporary Topics in Laboratory Animal Science / American Association for Laboratory Animal Science Abbreviated Journal Contemp Top Lab Anim Sci
Volume 41 Issue 2 Pages 51-56
Keywords Animals; Behavior, Animal; Biological Markers/*analysis; Cats/*physiology/psychology; Diet/veterinary; Feces/*chemistry; Food Coloring Agents/analysis; Housing, Animal; Individuality; Plastics/analysis; Specimen Handling/methods/*veterinary
Abstract The provision of proper social housing is a priority when designing an experiment using domestic cats as laboratory animals. When animals are group-housed, studies requiring analysis of stool samples from individual subjects pose difficulty in sample collection and identification. In this study, commercially available concentrated food colorings (known as bakers pastes) were used as fecal markers in group-housed cats. Cats readily consumed 0.5 ml of bakers paste food coloring once daily in canned cat food. Colorings served as fecal markers by imparting a distinct color to each cat s feces, allowing identification in the litter box. In addition, colored glitter (1/8 teaspoon in canned food) was fed to cats and found to be a reliable fecal marker. Long-term feeding of colorings and glitter was found to be safe and effective at yielding readily identifiable stools.
Address Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Alabama 36841, 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 1060-0558 ISBN Medium
Area Expedition Conference
Notes PMID:11958604 Approved no
Call Number Equine Behaviour @ team @ Serial 4165
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Author (up) Gulotta, M.; Gilmanshin, R.; Buscher, T.C.; Callender, R.H.; Dyer, R.B.
Title Core formation in apomyoglobin: probing the upper reaches of the folding energy landscape Type Journal Article
Year 2001 Publication Biochemistry Abbreviated Journal Biochemistry
Volume 40 Issue 17 Pages 5137-5143
Keywords Animals; Apoproteins/*chemistry; Computer Simulation; Horses; Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Myoglobin/*chemistry; *Protein Folding; Protein Structure, Secondary; Protein Structure, Tertiary; Spectrometry, Fluorescence/instrumentation/methods; Thermodynamics; Tryptophan/chemistry
Abstract An acid-destabilized form of apomyoglobin, the so-called E state, consists of a set of heterogeneous structures that are all characterized by a stable hydrophobic core composed of 30-40 residues at the intersection of the A, G, and H helices of the protein, with little other secondary structure and no other tertiary structure. Relaxation kinetics studies were carried out to characterize the dynamics of core melting and formation in this protein. The unfolding and/or refolding response is induced by a laser-induced temperature jump between the folded and unfolded forms of E, and structural changes are monitored using the infrared amide I' absorbance at 1648-1651 cm(-1) that reports on the formation of solvent-protected, native-like helix in the core and by fluorescence emission changes from apomyoglobin's Trp14, a measure of burial of the indole group of this residue. The fluorescence kinetics data are monoexponential with a relaxation time of 14 micros. However, infrared kinetics data are best fit to a biexponential function with relaxation times of 14 and 59 micros. These relaxation times are very fast, close to the limits placed on folding reactions by diffusion. The 14 micros relaxation time is weakly temperature dependent and thus represents a pathway that is energetically downhill. The appearance of this relaxation time in both the fluorescence and infrared measurements indicates that this folding event proceeds by a concomitant formation of compact secondary and tertiary structures. The 59 micros relaxation time is much more strongly temperature dependent and has no fluorescence counterpart, indicating an activated process with a large energy barrier wherein nonspecific hydrophobic interactions between helix A and the G and H helices cause some helix burial but Trp14 remains solvent exposed. These results are best fit by a multiple-pathway kinetic model when U collapses to form the various folded core structures of E. Thus, the results suggest very robust dynamics for core formation involving multiple folding pathways and provide significant insight into the primary processes of protein folding.
Address Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, 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 0006-2960 ISBN Medium
Area Expedition Conference
Notes PMID:11318635 Approved no
Call Number Equine Behaviour @ team @ Serial 3789
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Author (up) Gulotta, M.; Rogatsky, E.; Callender, R.H.; Dyer, R.B.
Title Primary folding dynamics of sperm whale apomyoglobin: core formation Type Journal Article
Year 2003 Publication Biophysical Journal Abbreviated Journal Biophys J
Volume 84 Issue 3 Pages 1909-1918
Keywords Animals; Apoproteins/*chemistry; Crystallography/*methods; Horses; Myocardium/chemistry; Myoglobin/*chemistry; Protein Conformation; *Protein Folding; Species Specificity; Structure-Activity Relationship; Temperature; Whales
Abstract The structure, thermodynamics, and kinetics of heat-induced unfolding of sperm whale apomyoglobin core formation have been studied. The most rudimentary core is formed at pH(*) 3.0 and up to 60 mM NaCl. Steady state for ultraviolet circular dichroism and fluorescence melting studies indicate that the core in this acid-destabilized state consists of a heterogeneous composition of structures of approximately 26 residues, two-thirds of the number involved for horse heart apomyoglobin under these conditions. Fluorescence temperature-jump relaxation studies show that there is only one process involved in Trp burial. This occurs in 20 micro s for a 7 degrees jump to 52 degrees C, which is close to the limits placed by diffusion on folding reactions. However, infrared temperature jump studies monitoring native helix burial are biexponential with times of 5 micro s and 56 micro s for a similar temperature jump. Both fluorescence and infrared fast phases are energetically favorable but the slow infrared absorbance phase is highly temperature-dependent, indicating a substantial enthalpic barrier for this process. The kinetics are best understood by a multiple-pathway kinetics model. The rapid phases likely represent direct burial of one or both of the Trp residues and parts of the G- and H-helices. We attribute the slow phase to burial and subsequent rearrangement of a misformed core or to a collapse having a high energy barrier wherein both Trps are solvent-exposed.
Address Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA. gulotta@aecom.yu.edu
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:12609893 Approved no
Call Number Equine Behaviour @ team @ Serial 3783
Permanent link to this record
 
 
Author (up) Hagen, S.J.; Eaton, W.A.
Title Two-state expansion and collapse of a polypeptide Type Journal Article
Year 2000 Publication Journal of Molecular Biology Abbreviated Journal J Mol Biol
Volume 301 Issue 4 Pages 1019-1027
Keywords Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics
Abstract The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse.
Address Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, 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 0022-2836 ISBN Medium
Area Expedition Conference
Notes PMID:10966803 Approved no
Call Number Equine Behaviour @ team @ Serial 3790
Permanent link to this record