Proteins are essential macromolecules that play diverse roles in the physiology and health of horses. They are composed of amino acids and are involved in various biological processes, including tissue growth, repair, and the synthesis of enzymes and hormones. Dietary proteins are a key component of equine nutrition, influencing muscle development, immune function, and overall performance. Horses require a balanced intake of essential amino acids, which must be obtained through their diet, as they cannot be synthesized endogenously. This page compiles peer-reviewed research studies and scholarly articles that explore the types, functions, and dietary requirements of proteins in horses, as well as their impact on equine health and performance.
Marcum JA, Highsmith RF, Kline DL.Complete activation of purified horse plasminogen to plasmin was obtained with a 1:10 molar ratio of streptokinase to plasminogen after 5 min of incubation at 37 degrees C. At a 1:1 molar ratio, maximal activity did not appear until 15-30 min, while at a ratio of 6:1 complete activation was delayed for 120-180 min. Gel filtration studies of isotopically labeled streptokinase and horse plasminogen suggest that the delay was due to impaired formation of a streptokinase-plasminogen complex. The predominant streptokinase moiety within the streptokinase-plasmin complex which forms from the streptok...
Heizmann CW, Berchtold MW, Rowlerson AM.The physiological role of the Ca2+-binding protein parvalbumin in skeletal muscle has been investigated by measuring the parvalbumin content by HPLC in a variety of mammalian muscles, including man, and comparing the results with the respective muscle relaxation properties and fiber type compositions. The parvalbumin concentrations were highest in the skeletal muscles of the smallest animal investigated (mouse, gastrocnemius: 4.9 g/kg), which has the highest relaxation speed, and lowest in the larger animals (horse, deep gluteal muscle: less than or equal to 0.001 g/kg) and man (vastus, tricep...
The Journal of hygieneDecember 1, 1982
Volume 89, Issue 3 529-538 doi: 10.1017/s0022172400071102
Corbel MJ, Brewer RA.Immunoelectrophoresis of ultrasonically disrupted Haemophilus equigenitalis (contagious equine metritis organism) cells against rabbit and equine antisera disclosed at least 11 precipitating antigens. Two of these, a polysaccharide and a lipopolysaccharide-protein complex, were of high molecular weight and located on the cell surface. The remaining antigens were intracellular and were small- to medium-sized proteins. The surface antigens were the most significant in relation to the serological response in infected horses. They also reacted with sera from apparently healthy cattle, but the reas...
Matthews AG.A method of electrophoresis of horse serum on agarose gels (pH 8.6) is described, together with a system for interpreting changes in the electrophoretic zones based upon the relative distribution of the major serum proteins. Differences in the protein composition of the individual electrophoretic zones of horses and ponies were recorded, although this variation probably reflects differences in management and the presence of subclinical disease.
Wurster U, Riese K, Hoffmann K.An attempt was made to establish normal values for the total protein concentrations and the enzyme activities of LDH, MDH and PGI in the intraocular fluids of rats, guinea pigs, rabbits, cats, dogs, sheep, cattle, pigs, horses and humans. Remarkably little species differences were noted in 9 of the 10 mammals with vitreal enzyme activities falling into a narrow range between 8.4 U/l (PGI, horse) and 92.4 U/l (MDH, guinea pig). All species obeyed the sequence aqueous less than vitreous less than serum with exception of the rat, where vitreous activities surpassed serum at least two-fold. The ve...
Green SA, Jenkins SJ, Clark PA.The biuret total protein method and a bromcresol green (BCG) albumin method were used on the Abbott ABA-100 chemistry analyzer to assay serum proteins in clinically normal cattle, sheep, ponies, pigs, and ducks. Total proteins were also read on a refractometer and mylar supported cellulose acetate electrophoresis was performed. Globulins and A/G ratios were calculated from the chemical method and the results compared with the electrophoretic method. Total protein, albumin and A/G ratios in the ponies, sheep and older cattle were in agreement between the two methods. The younger cattle and all ...
Skok MV, Denisiuk PV, Komissarenko SV.Glutaraldehyde treatment does not change the absorption of cytochrome c either in the visible or in UV spectra. It brings about the formation of dimers, trimers and high-polymeric forms of cytochrome c and shifts the pI of all cytochrome c isoelectric fractions to more acid pH. Polymerization also results in changes of kinetic parameters of cytochrome c benzidine reaction increasing its affinity to 3,3-diaminobenzidine with a simultaneous decrease in the effectiveness of H2O2 binding. These biochemical changes can be related to immunochemical differences of native and glutaraldehyde-treated cy...
Lanneau M, Loir M.Using standardized methods for protein extraction and analysis, the testes of rams, bulls, goats, boars, stallions, rats, cats, hedgehogs, European mink and ferrets were examined for basic spermatid nucleoproteins by electrophoresis. The results suggest that differences exist in the total number of these proteins as well as in the number and amount of the cross-linked cystein-containing proteins. These differences appear to be more family-specific than species-specific.
Keay G, Doxey DL.Samples of serum from both young and adult normal cattle, sheep and horses were subjected to protein electrophoresis on agarose gel films. After processing, the stained electrophoretic patterns and densitometric traces of each species exhibited certain specific characteristics. The separations also revealed differences between young and adult animals of the same species. These age-related differences are described here.
Jagodzinski PW, Funk GF, Peticolas WL.The nature of the binding of aromatic aldehyde and aromatic alcohol substrates to the catalytic zinc of equine liver alcohol dehydrogenase has been studied by using resonance-enhanced Raman spectroscopy. When an excess of both enzyme and coenzyme to substrate is used, a stable ternary chemical intermediate is formed between liver alcohol dehydrogenase and the reduced coenzyme, nicotinamide adenine dinucleotide, and the aldehyde, p-(dimethylamino)benzaldehyde, in the pH range 8.5-0.6. Resonance-enhanced Raman spectra clearly show that this same intermediate is formed between the excess enzyme, ...
Brems DN, Liu YC, Stellwagen E.The heme iron of horse heart cytochrome c was selectively removed using anhydrous HF. The product, porphyrin c, exhibits the viscosity, far ultraviolet circular dichroic, and fluorescence properties characteristic for native cytochrome c. However, porphyrin c is more susceptible to denaturation by guanidine hydrochloride and by heat than is the parent cytochrome. All of the conformational parameters of porphyrin c exhibit a common reversible transition centered at 0.95 m guanidine hydrochloride at 23 degrees C and pH 7.0. Guanidine denatured porphyrin c refolds in two kinetic phases having tim...
Pierrot M, Astier JP, Astier M, Charles M, Drenth J.A detailed study of the crystallization of hog and horse colipases has been undertaken. Several crystallographic varieties have been obtained and a 0.3-nm resolution structure determination is actually in progress. The sequence of the A form of horse colipase (one methionine) is given. From spectrophotometric experiments and sequence comparisons, the involvement of the aromatic residue in position 52 in the micelle binding site has been demonstrated.
Reitnour CM.The influence of administering caecal corn starch (0.0, 0.2, 0.4 or 0.6 g/kg body weight/day) on protein utilisation in 4 ponies was analysed with a latin square experimental design. The basal diet was dehydrated alfalfa pellets. Determinations were made of nitrogen retention, protein and dry matter digestions, total plasma protein, plasma urea nitrogen, plasma ammonia and plasma-free amino acids. Twice daily administration of corn starch into the caecum resulted in an increased nitrogen retention (P less than 0.01). Maximum nitrogen retention was observed with the caecal administration of 0.4...
Wagner AE, McIlwraith CW, Martin GS.Orgotein was injected into the right intercarpal joint of each of 8 horses; the corresponding left joint was left alone (not injected) or was given an injection of normal saline solution. Injection with orgotein caused a transient, marked inflammatory response, evidenced by clinical signs and by increased leukocytes and total protein in the synovia (synovial fluid). Leukocyte numbers and total protein concentration were increased (P less than 0.010) in the orgotein-injected joints within 24 hours. However, saline solution alone also elicited a marked inflammatory response, manifested by increa...
Visser S, Jenness R, Mullin RJ.Three groups of casein components were isolated from horse milk. Group I is almost insoluble at acid and neutral pH, and is rather heterogeneous on alkaline gels with or without sodium dodecyl sulphate. Group II shows strong similarity to beta-casein from other species, as concluded from its amino acid composition and its N- and C-terminal sequences. This group consists of five electrophoretically distinguishable forms, all containing ester phosphate groups but no carbohydrate. Group III is composed of C-terminal fragments of the beta-like (group II) fraction and probably arises from the actio...
Sklan D, Donoghue S.1. Serum and intracellular distribution of retinol was determined in equines maintained on four levels of vitamin A intake. 2. The form of retinol transported in serum was determined by gel filtration and chromatography to be a complex of retinol bound to a protein of molecular weight (MW) of approximately 20000, which was in turn complexed probably with prealbumin to yield a complex with a MW of 75000 to 80000. 3. Increasing dietary vitamin A levels enhanced the concentration of lipoprotein-bound retinyl esters in the plasma. 4. Vitamin A in the liver cytosol was found predominantly as retiny...
Gibbs PG, Potter GD, Blake RW, McMullan WC.Milk production was measured in fourteen Quarter Horse mares at seven stages of a 150-d lactation period. Mares were divided into two groups of seven and fed diets containing either soybean meal or soybean meal and urea as nitrogen supplements. Rations were isocaloric, contained approximately 12.5% crude protein and were fortified with vitamins and minerals. Daily milk yield was estimated by the weigh-suckle-weigh method and milk composition was determined from samples taken by hand milking. Average daily milk yield ranged from 11.8 kg in early lactation to 9.8 kg in late lactation. Difference...
A four-year-old thoroughbred was presented with clinical manifestations of purpura haemorrhagica. Evidence of renal involvement consistent with glomerulopathy and nephrotic syndrome, characterized by heavy proteinuria and azotaemia, became apparent and may have been exacerbated by diuretic therapy. Autopsy revealed membrano- and mesangial proliferative glomerulonephritis and chronic pleuritis. Circulating immune complexes may have been responsible for the renal diseases and the purpura.
Jörg A, Pasquier JM, Klebanoff SJ.Eosinophil peroxidase (donor: hydrogen-peroxidase oxidoreductase, EC 1.11.1.7) was isolated in a highly purified form (415/280 nm ratio, 1.05) from horse peripheral blood eosinophil. Eosinophil peroxidase was extracted from intact eosinophils (98-100% purity) or isolated eosinophil granules with 0.05 M acetate buffer (pH 4.7)/0.18 M NaCl and purified by chromatography on Sephadex G-200 and carboxymethylcellulose. Final elution was with 0.05 M acetate buffer (pH 4.7)/ 1 M NaCl. Horse eosinophil peroxidase is a strongly basic protein with bacterial properties when combined with H2O2 and iodide, ...
Roberts MC, Kelly WR.A four-year-old thoroughbred was presented with clinical manifestations of purpura haemorrhagica. Evidence of renal involvement consistent with glomerulopathy and nephrotic syndrome, characterised by heavy proteinuria and azotaemia, became apparent and may have been exacerbated by diuretic therapy. Autopsy revealed membrano- and mesangial proliferative glomerulonephritis and chronic pleuritis. Circulating immune complexes may have been responsible for the renal diseases and the purpura.
Wagner AE, Bennett DG.Eighteen clinically normal horses were used to study the characteristics of normal thoracic fluid. Thoracic fluid was obtained from each horse and was found to be similar to equine abdominal fluid. Total leukocytes averaged 3994/ul, total protein 1.8 g/dl, and specific gravity 1.015. Analysis of thoracic fluid from 16 horses with clinical signs of thoracic disease showed abnormalities in every case. Thoracic fluid analysis alone determined a specific diagnosis in 50% of the cases.
Berti A, Liguri G, Stefani M, Nassi P, Ramponi G.Horse muscle acylphosphatase antibodies were obtained by immunizing rabbits with the highly purified antigen cross-linked with glutaraldehyde. Specific antibodies were purified from the immunoglobulin fraction by affinity chromatography using a matrix coupled with the pure antigen as immunoadsorbent. The purified antibodies were partially characterized by immunodiffusion and immunoprecipitin techniques. These antibodies could be used to study aspects of the muscle acylphosphatase structure, localization and other biological properties.
Kotoński B.The purification of alpha-1,4-1,4-glucosyltransferase from the equine serum is presented. Ion-exchange chromatography on DE-11, DE-32 and CM-32 celluloses was applied in the successive steps of isolation. Gel-filtration on Bio-Gel P-200 was the last step of purification; it gave the protein which was homogeneous on disc polyacrylamide gel electrophoresis. The purification degree was of the order 2100 at about 40% yield.
Dzongowska-Dzongu T, Kotoński B, Hutny J.Alpha-1,4 leads to 1,4-glucosyltransferase preparations from horse muscles and serum were studied. The enzyme proteins from both tissues are very similar. Both proteins have a molecular weight of 240 000 and consist of four subunits of 60 000 daltons each. pH 5,0 is optimal for the activity. Only substrates with alpha-1, 4-linkages can serve as glucosyl donors for transferase reactions. Km values for both enzymes differ very slightly. At low substrate concentrations the hydrolytic activity can be found in addition to transferase reactions. At the concentration of the substrate higher than 40 m...
Li F, Stevenson RA, Crabb BS, Studdert MJ, Hartley CA.Equine rhinitis A virus (ERAV) is a significant pathogen of horses and is also closely related to Foot-and-mouth disease virus (FMDV). Despite these facts, knowledge of the prevalence and importance of ERAV infections remains limited, largely due to the absence of a simple, robust diagnostic assay. In this study, we compared the antigenicities of recombinant full-length and fragmented ERAV capsid proteins expressed in Escherichia coli by using sera from experimentally infected and naturally exposed horses. We found that, from the range of antigens tested, recombinant proteins encompassing the ...
Jabusch JR, Deutsch HF.The amino acid sequence of the high-activity equine erythrocyte carbonic anhydrase (CA-II) has been determined. Two different N-termini are noted, the C1 form having an N-acetyl-serine and the C2 form an N-acetyl-threonine. The sequence of the equine enzyme is most homologous to the human CA-II isozyme, with 224 of the 259 residues being identical.
Braend M, Romagnoli A.Starch gel electrophoresis of 55 donkey serum samples revealed three prealbumin (Pr) phenotypes temporarily designated Pr M, Pr MT and Pr T. The distribution was in agreement with a genetic theory of two codominant alleles of frequencies, PrM = 0.87 and PrT - 0.13. Variation was also observed for proteins migrating with the same rate as the Xh zones in the horse.
Matéos A, Girardet JM, Mollé D, Dary A, Miclo L, Gaillard JL.Because of variable degrees of phosphorylation, alternative splicing, and probable instability resulting from nonenzymatic deamidation, equine beta-casein presents a complex pattern by 2-dimensional electrophoresis that needs clarification. beta-Casein prepared from Haflinger mare's milk by hydrophobic interaction chromatography was fractionated by ion-exchange chromatography according to the degree of phosphorylation. Isoforms were identified by mass spectrometry; they corresponded to the full-length protein having 3 to 7 phosphate groups and to the splicing variant involving exon 5 and conta...
Waelchli RO, Lutz H, Hermann M, Eggenberger E.Eighteen healthy foals were studied from birth until 2 months of age. Blood samples were obtained at the following times: presuckle, 30 hours, 1, 3, 5, 7 and 9 weeks of age. Changes in serum P, Mg, Ca, Na, K, Cl, iron, AP, ASAT, ALAT, GGT, GLDH, CK, lipase, urea, creatinine, cholesterol, triglyceride, uric acid, protein and fibrinogen and in plasma total solids were examined and the values compared to reference values of adult horses. There were characteristic age related changes in several parameters. Single measurements should be interpreted cautiously to allow for individual variations.
Malark JA, Peyton LC, Galvin MJ.Peritoneal fluid and blood was collected from 8 healthy adult horses. Four 1-ml aliquots of peritoneal fluid from each horse were then contaminated with 0 ml (normal), 0.05 ml (1 drop), 0.10 ml (2 drops), and 0.20 ml (4 drops) of blood from the same horse. Samples were analyzed for RBC count, nucleated blood cell count, total protein concentration, and nucleated cell differential count. Statistical analysis revealed no significant changes in nucleated cell number, nucleated cell differential, or total protein concentration in peritoneal samples contaminated with blood. The RBC count significan...
Chesters PM, Steele M, Purewal A, Edington N.A 2.6 kb cDNA species has been isolated from a cDNA library prepared from interferon-alpha stimulated equine peripheral blood leucocytes and the nucleotide sequence determined. The cDNA has a single open reading frame potentially encoding a 660 amino acid polypeptide showing a high degree of homology with known mammalian Mx proteins, including the possession of three consensus GTP-binding motifs. The protein has a calculated pI = 6.1 and in accordance with proposed nomenclature we have designated it equine MxA.