Records |
Author |
Abbruzzetti, S.; Viappiani, C.; Sinibaldi, F.; Santucci, R. |
Title |
Kinetics of histidine dissociation from the heme Fe(III) in N-fragment (residues 1-56) of cytochrome c |
Type |
Journal Article |
Year |
2004 |
Publication |
The Protein Journal |
Abbreviated Journal |
Protein J |
Volume |
23 |
Issue |
8 |
Pages |
519-527 |
Keywords |
Animals; Cytochromes c/*chemistry; Enzyme Activation; Histidine/*chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Lasers; Ligands; Peptide Mapping; Photolysis; Spectrophotometry |
Abstract |
We have here investigated the dissociation kinetics of the His side chains axially ligated to the heme-iron in the ferric (1-56 residues) N-fragment of horse cyt c. The ligand deligation induced by acidic pH-jump occurs as a biexponential process with different pre-exponential factors, consistent with a structural heterogeneity in solution and the presence of two differently coordinated species. In analogy with GuHCl-denatured cyt c, our data indicate the presence in solution of two ferric forms of the N-fragment characterized by bis-His coordination, as summarized in the following scheme: His18-Fe(III)-His26 <==> His18-Fe(III)-His33. We have found that the pre-exponential factors depend on the extent of the pH-jump. This may be correlated with the different pKa values shown by His26 and His33; due to steric factors, His26 binds to the heme-Fe(III) less strongly than His33, as recently shown by studies on denatured cyt c. Interestingly, the two lifetimes are affected by temperature but not by the extent of the pH-jump. The lower pKa for the deligation reaction required the use of an improved laser pH-jump setup, capable of inducing changes in H+ concentration as large as 1 mM after the end of the laser pulse. For the ferric N-fragment, close activation entropy values have been determined for the two histidines coordinated to the iron; this result significantly differs from that for GuHCl-denatured cyt c, where largely different values of activation entropy were calculated. This underlines the role played by the missing segment (residues 57-104) peptide chain in discriminating deligation of the “nonnative” His from the sixth coordination position of the metal. |
Address |
Dipartimento di Fisica, Universita degli Studi di Parma, Parco Area delle Scienze 7/A 43100 Parma, Italy |
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English |
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Original Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1572-3887 |
ISBN |
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Notes |
PMID:15648974 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3770 |
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Author |
Permyakov, S.E.; Khokhlova, T.I.; Nazipova, A.A.; Zhadan, A.P.; Morozova-Roche, L.A.; Permyakov, E.A. |
Title |
Calcium-binding and temperature induced transitions in equine lysozyme: new insights from the pCa-temperature “phase diagrams” |
Type |
Journal Article |
Year |
2006 |
Publication |
Proteins |
Abbreviated Journal |
Proteins |
Volume |
65 |
Issue |
4 |
Pages |
984-998 |
Keywords |
Animals; Apoproteins/chemistry/metabolism; Binding Sites; Calcium/chemistry/*metabolism; Cattle; Edetic Acid/metabolism; Horses/metabolism; Hydrogen-Ion Concentration; Lactalbumin/chemistry/metabolism; Muramidase/*chemistry/*metabolism; Protein Denaturation; Spectrometry, Fluorescence; *Temperature; Thermodynamics; Tryptophan/chemistry/metabolism |
Abstract |
The most universal approach to the studies of metal binding properties of single-site metal binding proteins, i.e., construction of a “phase diagram” in coordinates of free metal ion concentration-temperature, has been applied to equine lysozyme (EQL). EQL has one relatively strong calcium binding site and shows two thermal transitions, but only one of them is Ca(2+)-dependent. It has been found that the Ca(2+)-dependent behavior of the low temperature thermal transition (I) of EQL can be adequately described based upon the simplest four-states scheme of metal- and temperature-induced structural changes in a protein. All thermodynamic parameters of this scheme were determined experimentally and used for construction of the EQL phase diagram in the pCa-temperature space. Comparison of the phase diagram with that for alpha-lactalbumin (alpha-LA), a close homologue of lysozyme, allows visualization of the differences in thermodynamic behavior of the two proteins. The thermal stability of apo-EQL (transition I) closely resembles that for apo-alpha-LA (mid-temperature 25 degrees C), while the thermal stabilities of their Ca(2+)-bound forms are almost indistinguishable. The native state of EQL has three orders of magnitude lower affinity for Ca(2+) in comparison with alpha-LA while its thermally unfolded state (after the I transition) has about one order lower (K = 15M(-1)) affinity for calcium. Circular dichroism studies of the apo-lysozyme state after the first thermal transition show that it shares common features with the molten globule state of alpha-LA. |
Address |
Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia |
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English |
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ISSN |
1097-0134 |
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Notes |
PMID:17022083 |
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no |
Call Number |
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Serial |
1858 |
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Author |
Chiba, K.; Ikai, A.; Kawamura-Konishi, Y.; Kihara, H. |
Title |
Kinetic study on myoglobin refolding monitored by five optical probe stopped-flow methods |
Type |
Journal Article |
Year |
1994 |
Publication |
Proteins |
Abbreviated Journal |
Proteins |
Volume |
19 |
Issue |
2 |
Pages |
110-119 |
Keywords |
Animals; Chromatography, Gel; Circular Dichroism; Horses; Kinetics; Metmyoglobin/analogs & derivatives/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Urea |
Abstract |
The refolding kinetics of horse cyanometmyoglobin induced by concentration jump of urea was investigated by five optical probe stopped-flow methods: absorption at 422 nm, tryptophyl fluorescence at around 340 nm, circular dichroism (CD) at 222 nm, CD at 260 nm, and CD at 422 nm. In the refolding process, we detected three phases with rate constants of > 1 x 10(2) s-1, (4.5-9.3) s-1, and (2-5) x 10(-3) s-1. In the fastest phase, a substantial amount of secondary structure (approximately 40%) is formed within the dead time of the CD stopped-flow apparatus (10.7 ms). The kinetic intermediate populated in the fastest phase is shown to capture a hemindicyanide, suggesting that a “heme pocket precursor” recognized by hemindicyanide must be constructed within the dead time. In the middle phase, most of secondary and tertiary structures, especially around the captured hemindicyanide, have been constructed. In the slowest phase, we detected a minor structural rearrangement accompanying the ligand-exchange reaction in the fifth coordination of ferric iron. We present a possible model for the refolding process of myoglobin in the presence of the heme group. |
Address |
Laboratory of Biodynamics, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Kanagawa, Japan |
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English |
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ISSN |
0887-3585 |
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Notes |
PMID:8090705 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3799 |
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Author |
Boucher, J.M.; Hanosset, R.; Augot, D.; Bart, J.M.; Morand, M.; Piarroux, R.; Pozet-Bouhier, F.; Losson, B.; Cliquet, F. |
Title |
Detection of Echinococcus multilocularis in wild boars in France using PCR techniques against larval form |
Type |
Journal Article |
Year |
2005 |
Publication |
Veterinary Parasitology |
Abbreviated Journal |
Vet Parasitol |
Volume |
129 |
Issue |
3-4 |
Pages |
259-266 |
Keywords |
Animals; Base Sequence; DNA, Helminth/chemistry/genetics; Echinococcosis/parasitology/pathology/*veterinary; Echinococcus multilocularis/*isolation & purification; Electron Transport Complex IV/chemistry/genetics; France; Histocytochemistry/veterinary; Liver/parasitology/pathology; Male; Molecular Sequence Data; Polymerase Chain Reaction/veterinary; Sequence Alignment; Sus scrofa/*parasitology; Swine Diseases/*parasitology/pathology |
Abstract |
Recently, new data have been collected on the distribution and ecology of Echinococcus multilocularis in European countries. Different ungulates species such as pig, goat, sheep, cattle and horse are known to host incomplete development of larval E. multilocularis. We report a case of E. multilocularis portage in two wild boars from a high endemic area in France (Department of Jura). Histological examination was performed and the DNA was isolated from hepatic lesions then amplified by using three PCR methods in two distinct institutes. Molecular characterisation of PCR products revealed 99% nucleotide sequence homology with the specific sequence of the U1 sn RNA gene of E. multilocularis, 99 and 99.9% nucleotide sequence homology with the specific sequence of the cytochrome oxydase gene of Echinococcus genus and 99.9% nucleotide sequence homology with a genomic DNA sequence of Echinococcus genus for the first and the second wild boar, respectively. |
Address |
AFSSA Nancy, Laboratoire d'Etudes et de Recherches sur la Rage et la Pathologie des Animaux Sauvages, Domaine de Pixerecourt-B.P. 9, Malzeville F 54220, France |
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English |
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Abbreviated Series Title |
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Edition |
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ISSN |
0304-4017 |
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Notes |
PMID:15845281 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
2629 |
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Author |
Nicol, C.J.; Davidson, H.P.D.; Harris, P.A.; Waters, A.J.; Wilson, A.D. |
Title |
Study of crib-biting and gastric inflammation and ulceration in young horses |
Type |
Journal Article |
Year |
2002 |
Publication |
The Veterinary record |
Abbreviated Journal |
Vet. Rec. |
Volume |
151 |
Issue |
22 |
Pages |
658-662 |
Keywords |
Animal Husbandry/methods; Animals; Antacids/therapeutic use; *Behavior, Animal; Diet/veterinary; Endoscopy, Gastrointestinal/veterinary; Feces/chemistry; Female; Gastritis/diet therapy/physiopathology/*veterinary; Horse Diseases/diet therapy/*physiopathology/psychology; Horses; Hydrogen-Ion Concentration; Male; Random Allocation; Stereotyped Behavior/*physiology; Stomach Ulcer/diet therapy/physiopathology/*veterinary; Treatment Outcome; Weaning |
Abstract |
Nineteen young horses that had recently started to perform the stereotypy of crib-biting were compared with 16 non-stereotypic horses for 14 weeks. After initial observations of their behaviour and an endoscopic examination of the condition of their stomachs, the horses were randomly allocated to a control or an antacid diet At the start of the trial, the stomachs of the crib-biting foals were significantly more ulcerated and inflamed than the stomachs of the normal foals. In addition, the faecal pH of the crib-biting foals (6.05) was significantly lower than that of the normal foals (6.58). The antacid diet resulted in a significant improvement in the condition of the horses' stomachs. The crib-biting behaviour declined in most of the foals, regardless of their diet, but tended to decline to a greater extent in the foals on the antacid diet. |
Address |
Department of Clinical Veterinary Science, University of Bristol, Langford House, Bristol BS40 5DU |
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English |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0042-4900 |
ISBN |
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Conference |
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Notes |
PMID:12498408 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
83 |
Permanent link to this record |