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Topic:Spectroscopy

Spectroscopy is an analytical technique used to measure the interaction between matter and electromagnetic radiation. In equine research, spectroscopy is applied to assess various biological and chemical properties of horses. Techniques such as infrared spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry are utilized to analyze tissues, fluids, and other biological samples. These methods provide insights into metabolic processes, nutritional status, and disease states in horses. Spectroscopy aids in the identification and quantification of biomolecules, contributing to the understanding of equine physiology and pathology. This page compiles peer-reviewed research studies and scholarly articles that explore the application, methodology, and findings of spectroscopic techniques in equine science.
Muscle fiber population and biochemical properties of whole body muscles in Thoroughbred horses.
Anatomical record (Hoboken, N.J. : 2007)    September 4, 2009   Volume 292, Issue 10 1663-1669 doi: 10.1002/ar.20961
Kawai M, Minami Y, Sayama Y, Kuwano A, Hiraga A, Miyata H.We examine the muscle fiber population and metabolic properties of skeletal muscles from the whole body in Thoroughbred horses. Postmortem samples were taken from 46 sites in six Thoroughbred horses aged between 3 and 6 years. Fiber type population was determined on muscle fibers stained with monoclonal antibody to each myosin heavy chain isoform and metabolic enzyme activities were determined spectrophotometrically. Histochemical analysis demonstrated that most of the muscles had a high percentage of Type IIa fibers. In terms of the muscle characteristic in several parts of the horse body, th...
Protein oligomerization induced by oleic acid at the solid-liquid interface–equine lysozyme cytotoxic complexes.
The FEBS journal    July 7, 2009   Volume 276, Issue 15 3975-3989 doi: 10.1111/j.1742-4658.2009.07107.x
Wilhelm K, Darinskas A, Noppe W, Duchardt E, Mok KH, Vukojević V, Schleucher J, Morozova-Roche LA.Protein oligomeric complexes have emerged as a major target of current research because of their key role in aggregation processes in living systems and in vitro. Hydrophobic and charged surfaces may favour the self-assembly process by recruiting proteins and modifying their interactions. We found that equine lysozyme assembles into multimeric complexes with oleic acid (ELOA) at the solid-liquid interface within an ion-exchange chromatography column preconditioned with oleic acid. The properties of ELOA were characterized using NMR, spectroscopic methods and atomic force microscopy, and showed...
NMR and computational studies of stereoisomeric equine estrogen-derived DNA cytidine adducts in oligonucleotide duplexes: opposite orientations of diastereomeric forms.
Biochemistry    June 17, 2009   Volume 48, Issue 30 7098-7109 doi: 10.1021/bi9006429
Zhang N, Ding S, Kolbanovskiy A, Shastry A, Kuzmin VA, Bolton JL, Patel DJ, Broyde S, Geacintov NE.The equine estrogens equilin (EQ) and equilenin (EN) are the active components in the widely prescribed hormone replacement therapy formulation Premarin. Metabolic activation of EQ and EN generates the catechol 4-hydroxyequilenin (4-OHEN) that autoxidizes to the reactive o-quinone form in aerated aqueous solutions. The o-quinones react predominantly with C, and to a lesser extent with A and G, to form premutagenic cyclic covalent DNA adducts in vitro and in vivo. To obtain insights into the structural properties of these biologically important DNA lesions, we have synthesized site-specifically...
A multifrequency HYSCORE study of weakly coupled nuclei in frozen solutions of high-spin aquometmyoglobin.
Inorganic chemistry    February 21, 2009   Volume 47, Issue 23 11294-11304 doi: 10.1021/ic8016886
García-Rubio I, Fittipaldi M, Trandafir F, Van Doorslaer S.In this work, we show the extreme power of multifrequency HYSCORE (hyperfine sublevel correlation spectroscopy) techniques to unravel the hyperfine interactions of the electron spin with the remote nuclei in the heme site of high-spin ferric heme proteins. Horse heart aquo-metmyoglobin was used as a model system to demonstrate the power of these techniques. Experimental evidence was collected and assigned to protons of the proximal histidine ligand, to the mesoprotons of the heme ligand, and to two different protons of the distal water ligand. The latter difference relates to the stabilization...
The structure of the polysaccharide of the lipopolysaccharide produced by Taylorella equigenitalis type strain (ATCC 35865).
Carbohydrate research    September 24, 2008   Volume 343, Issue 18 3079-3084 doi: 10.1016/j.carres.2008.09.015
Vinogradov E, MacLean LL, Brooks BW, Lutze-Wallace C, Perry MB.Taylorella equigenitalis is a Gram-negative bacterium that causes venereally transmitted contagious equine metritis (CEM), and its identification and differentiation from other bacteria and Taylorella species is an important requirement for the control of CEM infection. Based on the results of NMR and MS analysis, the antigenic O-polysaccharide (O-PS) component of the lipopolysaccharide (LPS) produced by the type strain T. equigenitalis (ATCC 35865) was found to be a linear polymer composed of a repeating disaccharide unit, containing partially amidated 2,3-diacetamido-2,3-dideoxy-alpha-L-gulu...
Comparative activities of semicarbazide-sensitive amine oxidase (SSAO) in five domestic species.
Polish journal of veterinary sciences    June 11, 2008   Volume 11, Issue 1 63-66 
Al-Wabel NA.Semicarbazide-sensitive amine oxidase (SSAO) activity was measured spectrophotometrically using benzylamine as a substrate, in the serum of healthy males and females of horses, camels, cattle, sheep and goats. The animals were born and raised in the same area, and the blood collection was made on the same day to avoid variations. Also the concentrations of protein and copper were measured in the same samples. There were no significant gender-related differences in SSAO activity between the tested animals regardless of species. Activities of SSAO in either male or female of horse were significa...
Comparative structural and chemical studies of ferritin cores with gradual removal of their iron contents.
Journal of the American Chemical Society    May 29, 2008   Volume 130, Issue 25 8062-8068 doi: 10.1021/ja800492z
Gálvez N, Fernández B, Sánchez P, Cuesta R, Ceolín M, Clemente-León M, Trasobares S, López-Haro M, Calvino JJ, Stéphan O, Domínguez-Vera JM.Transmission Electron Microscopy (TEM), X-ray Absorption Near Edge Spectroscopy (XANES), Electron Energy-Loss Spectroscopy (EELS), Small-Angle X-ray Scattering (SAXS), and SQUID magnetic studies were performed in a batch of horse spleen ferritins from which iron had been gradually removed, yielding samples containing 2200, 1200, 500, and 200 iron atoms. Taken together, findings obtained demonstrate that the ferritin iron core consists of a polyphasic structure (ferrihydrite, magnetite, hematite) and that the proportion of phases is modified by iron removal. Thus, the relative amount of magneti...
Phospholipid compositions of sera and synovial fluids from dog, human and horse: a comparison by 31P-NMR and MALDI-TOF MS.
Journal of animal physiology and animal nutrition    May 20, 2008   Volume 93, Issue 4 410-422 doi: 10.1111/j.1439-0396.2008.00822.x
Fuchs B, Bondzio A, Wagner U, Schiller J.Alterations of the phospholipid (PL) compositions of body fluids are assumed to be indicative of inflammatory diseases, e.g. rheumatoid arthritis (RA). Recently, we have shown that particularly the phosphatidylcholine/lysophosphatidylcholine (PC/LPC) ratio determined in human synovial fluids (SF) and sera represents a reliable measure of the inflammatory state in RA patients. However, it is not yet clear to what extent the PC/LPC ratio is also affected by nutrition habits. In the present study, the PL and the corresponding acyl chain compositions of human body fluids (SF and serum of RA patien...
Correlation of acid-induced conformational transition of ferricytochrome c with cyanide binding kinetics.
Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry    March 4, 2008   Volume 13, Issue 5 713-721 doi: 10.1007/s00775-008-0357-8
Varhac R, Antalík M.A relation between pH-induced conformational transitions of horse heart ferricytochrome c and the kinetics of external ligand coordination to heme iron was investigated by optical spectroscopy, circular dichroism and viscometry. The dependencies of both the association, k (a), and dissociation rate constants of cyanide binding on pH were determined from kinetic measurements. The association rate constant exhibits a bell-shaped form of dependence on pH in the region where this protein unfolds. The maximum of the dependence of k (a) on pH is found to be coincident with the pK values of conformat...
Specific electrochemical iodination of horse heart myoglobin at tyrosine 103 as determined by Fourier transform ion cyclotron resonance mass spectrometry.
Archives of biochemistry and biophysics    February 29, 2008   Volume 474, Issue 1 1-7 doi: 10.1016/j.abb.2008.02.032
Iniesta J, Cooper HJ, Marshall AG, Heptinstall J, Walton DJ, Peterson IR.The iodination of proteins remains a useful tool in biochemistry for radiolabelling. However, chemical or enzymatic iodination is difficult to control and can give deleterious polyiodination. Previously, we have shown that electrooxidation with nitrite is a rapid method for the selective nitration of tyrosine residues in proteins. In principle, it should be possible to substitute a number of electrooxidisable anions into the tyrosine phenol ring. Electrochemical iodination is more difficult to control than nitration because the rapid anodic oxidation of I(-) leads to persistent formation of th...
1H NMR investigation of normal and osteo-arthritic synovial fluid in the horse.
Veterinary and comparative orthopaedics and traumatology : V.C.O.T    February 22, 2008   Volume 21, Issue 1 85-88 doi: 10.3415/VCOT-06-12-0101
Lacitignola L, Fanizzi FP, Francioso E, Crovace A.Proton magnetic resonance spectroscopy (1H NMR) has been successfully used in the study of many biological fluids. The data presented here report on the metabolic profiles of normal equine synovial fluids compared with osteoarthritic (OA) fluids. Twenty-five OA synovial fluid samples and eight normal ones were collected from the forelimb fetlock joint in 22 horses, aged between five and 24 years. 1H NMR spectroscopy was carried out with a Bruker Avance DRX 500 equiped with a cryo-magnet working at 11 Tesla, and 'Mestre-C 4.9.9.6' software was used to analyze the spectra. The study assessed the...
The effect of pre-polymeric solution and subsequent encapsulation in hydrogel membranes on the stability and biological activity of horse myoglobins. Valentín-Rodríguez C, López-Garriga J, Torres-Lugo M.Proteins are biological macromolecules which have a unique spatial conformation. Once this 3D spatial conformation is affected the protein's biological stability and activity can be severely limited. For these reasons, this investigation focuses on the effects of pre-polymeric solution components on the behavior of proteins to be encapsulated by the entrapment technique in anionic, cationic, and neutral hydrogel membranes. Equine skeletal muscle myoglobin (MMb), and equine heart myoglobin (HMb) were employed as model molecules. Three hydrogel morphologies were examined: methacrylic acid-poly(e...
Serum concentration of copper, zinc, iron, and cobalt and the copper/zinc ratio in horses with equine herpesvirus-1.
Biological trace element research    September 13, 2007   Volume 118, Issue 1 38-42 doi: 10.1007/s12011-007-0023-y
Yörük I, Deger Y, Mert H, Mert N.The serum concentrations of copper, zinc, iron, and cobalt and copper/zinc ratio were investigated in horses infected with equine herpesvirus-1 (EHV-1). Nine horses were naturally infected with the virus and nine healthy horses served as controls. The concentrations of copper, zinc, iron, and cobalt were determined spectrophotometrically in the blood serum of all horses. The results were (expressed in micrograms per deciliters) copper 2.80 +/- 0.34 vs 1.12 +/- 0.44, zinc 3.05 +/- 0.18 vs 0.83 +/- 0.06, iron 2.76 +/- 0.17 vs 3.71 +/- 0.69, cobalt 0.19 +/- 0.37 vs 0.22 +/- 0.45, and copper/zinc ...
Use of Fourier-transform infrared spectroscopy for the diagnosis of failure of transfer of passive immunity and measurement of immunoglobulin concentrations in horses.
Journal of veterinary internal medicine    August 22, 2007   Volume 21, Issue 4 828-834 doi: 10.1892/0891-6640(2007)21[828:uofisf]2.0.co;2
Riley CB, McClure JT, Low-Ying S, Shaw RA.The economic, accurate, and rapid screening of foals for failure of transfer of passive immunity (FPT) is essential to ensure timely intervention. Objective: Infrared (IR) spectroscopy of foal sera and pattern recognition may be used to diagnose FPT and quantify serum IgG. Methods: Sera from 194 foals (24-72 hours) with serum immunoglobulin G (IgG) concentrations determined previously by radial immunodiffusion assay (RID) were used. Methods: IR spectra were recorded for the serum samples, and the data were randomly divided into training and independent test sets, each containing both FPT-posit...
Ruthenium anticancer drugs and proteins: a study of the interactions of the ruthenium(III) complex imidazolium trans-[tetrachloro(dimethyl sulfoxide)(imidazole)ruthenate(III)] with hen egg white lysozyme and horse heart cytochrome c.
Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry    August 7, 2007   Volume 12, Issue 8 1107-1117 doi: 10.1007/s00775-007-0280-4
Casini A, Mastrobuoni G, Terenghi M, Gabbiani C, Monzani E, Moneti G, Casella L, Messori L.The interactions with protein targets of the ruthenium(III) complex imidazolium trans-[tetrachloro(dimethyl sulfoxide)(imidazole)ruthenate(III)], NAMI-A, an effective anticancer and antimetastatic agent now in clinical trials, deserve great attention as they are believed to be at the basis of the mechanism of action of this innovative molecule. Here, we report on the reactions of NAMI-A with two well-known model proteins, namely, hen egg white lysozyme and horse heart cytochrome c; these reactions were investigated by a variety of physicochemical methods, including optical spectroscopy, (1)H N...
Identification of infrared absorption spectral characteristics of synovial fluid of horses with osteochondrosis of the tarsocrural joint.
American journal of veterinary research    May 3, 2007   Volume 68, Issue 5 517-523 doi: 10.2460/ajvr.68.5.517
Vijarnsorn M, Riley CB, Ryan DA, Rose PL, Shaw RA.To determine the feasibility of the use of Fourier-transform infrared (FTIR) spectroscopy within the midinfrared range to differentiate synovial fluid samples of joints with osteochondrosis from those of control samples. Methods: 33 horses with osteochondrosis of the tarsocrural joint and 31 horses free of tarsocrural joint disease. Methods: FTIR spectroscopy of synovial fluid was used. Sixty-four synovial fluid samples from the tarsocrural joint were collected. Of these, 33 samples were from horses with radiographic evidence of osteochondrosis of the tarsocrural joint and 31 from control join...
In vitro effects of oxygen on physico-chemical properties of horse erythrocyte membrane.
Environmental toxicology and pharmacology    December 27, 2006   Volume 23, Issue 3 340-346 doi: 10.1016/j.etap.2006.12.002
Portier K, Guichardant M, Debouzy JC, Crouzier D, Geraud I, Kirschvink N, Lekeux P, Fellmann N, Coudert J.Whether direct exposure to different concentrations (0%, 13%, 100%) of oxygen may affect horse erythrocyte membrane fluidity (EMF) and fatty acid (FA) composition was studied during 1 (T60) and 2h (T120) exposure. EMF was investigated at the head group level and hydrophobic core thanks to phosphorus nucleus 31 ((31)P) nuclear magnetic resonance ((31)P NMR) and electronic paramagnetic resonance (EPR) using two spin probes: 5-nitroxydestearic acid and 16-doxylstearic acid. Lipid structure of the membranes was studied by gas liquid chromatography. 4-Hydroxy-2E-nonenal was also analyzed as a marke...
Reliability of 1,9-dimethylmethylene blue tests in comparison to agarose gel electrophoresis for quantification of urinary glycosaminoglycans.
Clinica chimica acta; international journal of clinical chemistry    December 14, 2006   Volume 378, Issue 1-2 206-215 doi: 10.1016/j.cca.2006.11.025
de Lima CR, Baccarin RY, Michelacci YM.The relevance of glycosaminoglycan determination in biological fluids is gradually gaining importance in the literature. Nevertheless, the results obtained by different methods vary widely. We evaluated 1,9-dimethylmethylene blue (DMB) dye-binding assays for quantification of urinary glycosaminoglycans, in comparison to densitometry after agarose gel electrophoresis. Methods: Urinary glycosaminoglycans from different mammalian species were quantified by 3 different DMB dye-binding assays. The results were compared to those obtained by densitometry after agarose gel electrophoresis of glycosami...
Fecal NIRS: detection of tick infestations in cattle and horses.
Veterinary parasitology    November 13, 2006   Volume 144, Issue 1-2 146-152 doi: 10.1016/j.vetpar.2006.09.018
Tolleson DR, Teel PD, Stuth JW, Strey OF, Welsh TH, Carstens GE.Anti-tick treatments are often applied concurrent to routine livestock management practices with little regard to actual infestation levels. Prescription treatments against ticks on grazing cattle would be facilitated by non-invasive detection methods. One such method is fecal near infrared spectroscopy (NIRS). Four studies utilizing cattle (Bos spp.) and one with horses (Equus caballus) fed varying diets and infested with either Amblyomma americanum, A. maculatum, A. cajennense or Dermacentor albipictus were conducted to determine the ability of fecal NIRS to identify samples from animals wit...
Quantitative genetic aspects of coat color in horses.
Journal of animal science    September 15, 2006   Volume 84, Issue 10 2623-2628 doi: 10.2527/jas.2005-704
Toth Z, Kaps M, Sölkner J, Bodo I, Curik I.The aim of this study was to estimate genetic parameters for coat color in horses. Besides defining coat color classes (gray, chestnut, bay, and black), the phenotypes were also measured quantitatively according to standardized international procedures (Commission Internationale de l'Eclairage L*, a*, b*), where L* describes lightness, a* describes color saturation from red to green, and b* describes color saturation from yellow to blue. The total color saturation was derived from a* and b* and referred to as Chroma. A total of 294 horses from the breeds Lipizzan, Nonius, Arabian Pure Bred, Sh...
Use of infrared spectroscopy for diagnosis of traumatic arthritis in horses.
American journal of veterinary research    August 3, 2006   Volume 67, Issue 8 1286-1292 doi: 10.2460/ajvr.67.8.1286
Vijarnsorn M, Riley CB, Shaw RA, McIlwraith CW, Ryan DA, Rose PL, Spangler E.To evaluate use of infrared spectroscopy for diagnosis of traumatic arthritis in horses. Methods: 48 horses with traumatic arthritis and 5 clinically and radiographically normal horses. Methods: Synovial fluid samples were collected from 77 joints in 48 horses with traumatic arthritis. Paired samples (affected and control joints) from 29 horses and independent samples from an affected (n = 12) or control (7) joint from 19 horses were collected for model calibration. A second set of 20 normal validation samples was collected from 5 clinically and radiographically normal horses. Fourier transfor...
Fourier transform infrared imaging spectroscopy investigations in the pathogenesis and repair of cartilage.
Biochimica et biophysica acta    May 23, 2006   Volume 1758, Issue 7 934-941 doi: 10.1016/j.bbamem.2006.05.014
Bi X, Yang X, Bostrom MP, Camacho NP.Significant complications in the management of osteoarthritis (OA) are the inability to identify early cartilage changes during the development of the disease, and the lack of techniques to evaluate the tissue response to therapeutic and tissue engineering interventions. In recent studies several spectroscopic parameters have been elucidated by Fourier transform infrared imaging spectroscopy (FT-IRIS) that enable evaluation of molecular and compositional changes in human cartilage with progressively severe OA, and in repair cartilage from animal models. FT-IRIS permits evaluation of early-stag...
Validation of the sperm mobility assay in boars and stallions.
Theriogenology    April 27, 2006   Volume 66, Issue 5 1091-1097 doi: 10.1016/j.theriogenology.2006.02.048
Vizcarra JA, Ford JJ.The sperm mobility assay used in the present study measures the rate of sperm penetration in a biologically inert cell-separation solution (Accudenz). When a sample of sperm is overlaid in a cuvette containing Accudenz, sperm penetrate the solution and absorbance of the sample can be measured with a spectrophotometer. This assay has been successfully used to select chicken and turkey semen donors. We validated this assay for semen from boars and stallions. Absorbance was measured after overlaying fresh semen from each species in prefilled cuvettes for 1, 5, 10, 15, 20, and 40 min. There were n...
Use of 13C-acetate breath test for assessment of gastric emptying in horses.
The Journal of veterinary medical science    November 9, 2005   Volume 67, Issue 10 993-997 doi: 10.1292/jvms.67.993
Sasaki N, Aiuchi H, Yamada H.This study aimed to establish and standardize a breath test that uses 13C-acetate in a liquid diet for evaluation of gastric emptying in horses. Seven adult healthy thoroughbreds were used in this study. They were given 13C-acetate (125 mg, 250 mg, or 500 mg) in a test meal (2000 ml liquid diet) via an intranasal catheter. 13C concentrations in the exhaled CO2 were measured in samples taken before and after test meal administration using an infrared absorption spectroscope. In the 500 mg 13C-acetate group, Delta13CO2 showed a steep gradient immediately after meal administration compared to the...
Twenty-eight element concentrations in mane hair samples of adult riding horses determined by particle-induced X-ray emission.
Biological trace element research    October 12, 2005   Volume 107, Issue 2 135-140 doi: 10.1385/BTER:107:2:135
Asano K, Suzuki K, Chiba M, Sera K, Asano R, Sakai T.The concentrations of 28 elements (Al, Br, Ca, Cl, Co, Cu, Cr, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Se, Si, Sr, Ti, V, Y, and Zn) were measured in mane hair by the particle-induced X-ray emission method. Except for Br, Cl, K, S, and P, the trace element concentrations in mane hair of horses are similar to literature values for human hair. The values obtained are not dependent on the horse's age, breed, and sex and could be used as reference values in the assessment of diseases and nutritional status in equines.
A novel method for determination of collagen orientation in cartilage by Fourier transform infrared imaging spectroscopy (FT-IRIS).
Osteoarthritis and cartilage    September 9, 2005   Volume 13, Issue 12 1050-1058 doi: 10.1016/j.joca.2005.07.008
Bi X, Li G, Doty SB, Camacho NP.The orientation of collagen molecules is an important determinant of their functionality in connective tissues. The objective of the current study is to establish a method to determine the alignment of collagen molecules in histological sections of cartilage by polarized Fourier transform infrared imaging spectroscopy (FT-IRIS), a method based on molecular vibrations. Methods: Polarized FT-IRIS data obtained from highly oriented tendon collagen were utilized to calibrate the derived spectral parameters. The ratio of the integrated areas of the collagen amide I/II absorbances was used as an ind...
Fluorescence spectra and measurement of phylloerythrin (phytoporphyrin) in plasma from clinically healthy sheep, goats, cattle and horses.
New Zealand veterinary journal    July 21, 2005   Volume 51, Issue 4 191-193 doi: 10.1080/00480169.2003.36363
Scheie E, Flaoyen A.To measure the background concentration of phylloerythrin in plasma from clinically healthy sheep, goats, cattle and horses on pasture. Methods: Blood samples were taken from 34 sheep of the Dala breed, 20 female Norwegian dairy goats, 35 Norwegian Red cows and 34 horses of different breeds. All animals were grazing green pasture when blood samples were taken. Blood samples were collected from each of four clinically healthy newborn lambs, goats, calves and foals, and pooled into one sample per species. Plasma samples were analysed for phylloerythrin by fluorescence spectroscopy, using a Perki...
Effect of maximal dynamic exercise on exhaled ethane and carbon monoxide levels in human, equine, and canine athletes.
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology    June 30, 2005   Volume 141, Issue 2 239-246 doi: 10.1016/j.cbpb.2005.05.046
Wyse C, Cathcart A, Sutherland R, Ward S, McMillan L, Gibson G, Padgett M, Skeldon K.Exercise-induced oxidative stress (EIOS) refers to a condition where the balance of free radical production and antioxidant systems is disturbed during exercise in favour of pro-oxidant free radicals. Breath ethane is a product of free radical-mediated oxidation of cell membrane lipids and is considered to be a reliable marker of oxidative stress. The heatshock protein, haem oxygenase, is induced by oxidative stress and degrades haemoglobin to bilirubin, with concurrent production of carbon monoxide (CO). The aim of this study was to investigate the effect of maximal exercise on exhaled ethane...
Ultrafast events in the folding of ferrocytochrome c.
Biochemistry    June 29, 2005   Volume 44, Issue 26 9359-9367 doi: 10.1021/bi050384b
Kumar R, Prabhu NP, Bhuyan AK.Laser flash photolysis and stopped-flow methods have been used to study the dynamic events in the micro- to millisecond time bin in the refolding of horse ferrocytochrome c in the full range of guanidine hydrochloride concentration at pH 12.8 (+/-0.1), 22 degrees C. Under the absolute refolding condition, the earliest relaxation time of the unfolded protein chain is less than 1 micros. The chain then undergoes diffusive dynamics-mediated contraction and expansion, in which intrapolypeptide ligands make transient contacts with the heme iron, giving rise to two distinct kinetic phases of approxi...
The influence of anticoagulants on the measurement of total protein concentration in equine peritoneal fluid.
Research in veterinary science    June 9, 2005   Volume 80, Issue 1 5-10 doi: 10.1016/j.rvsc.2005.03.007
Estepa JC, Lopez I, Mayer-Valor R, Rodriguez M, Aguilera-Tejero E.The aim of this study was to evaluate the influence of two commonly used anticoagulants (K3EDTA and lithium heparin) on refractometric and spectrophotometric measurement of total protein (TP) concentration in equine peritoneal fluid samples. The influence of a commercial solution of K3EDTA, a solution of K3EDTA in distilled water and lithium heparin on the refractometric and spectrophotometric (biuret) quantification of TP content in peritoneal fluid samples was assessed. Total protein concentration measured by refractometry was consistently overestimated in samples with commercial K3EDTA. The...
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