Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Amino Acids
Amino acids are organic compounds that serve as the building blocks of proteins and play crucial roles in various physiological processes in horses. They are essential for growth, tissue repair, and the synthesis of enzymes and hormones. Amino acids are categorized into essential amino acids, which must be obtained through the diet, and non-essential amino acids, which can be synthesized by the horse's body. Key essential amino acids for equine health include lysine, methionine, and threonine, which are vital for muscle development, immune function, and overall well-being. Amino acid levels can influence performance, recovery, and metabolic efficiency in horses, making their study important for optimizing equine nutrition and health management. This page compiles peer-reviewed research studies and scholarly articles that explore the role, metabolism, and clinical importance of amino acids in equine physiology and their impact on performance and health outcomes.
Heterogeneity of amino acid transport in horse erythrocytes: a detailed kinetic analysis of inherited transport variation. 1. Thoroughbred horses were divisible into five distinct amino acid transport subgroups on the basis of their erythrocyte permeability to L-alanine, measured uptake rates ranging from 5 to 625 mumol l cells-1 h-1 (0.2 mM-extracellular L-alanine, 37 degrees C). 2. Erythrocytes from animals belonging to the lowest L-alanine permeability subgroup (5-15 mumol l cells-1 h-1) (transport-deficient type) exhibited slow nonsaturable transport of this amino acid. In contrast, cells from horses of the four transport-positive subgroups possessed additional high-affinity (apparent L-alanine Km (Michaelis c...
Structural studies on equine glycoprotein hormones. Amino acid sequence of equine chorionic gonadotropin beta-subunit. The complete amino acid sequence of the beta-subunit of equine chorionic gonadotropin (eCG beta) has been established by both automated Edman and manual 5-dimethylaminonaphthalene-1-sulfonyl-Edman degradations. Specific fragments were produced by cleavage with Staphylococcus aureus V8 protease, trypsin, or dilute HCl. For the sequence analyses of the heavily glycosylated COOH-terminal portion, a chemical deglycosylation procedure with trifluoromethanesulfonic acid was employed. The peptide chain of eCG beta consists of 149 amino acid residues. Five or more oligosaccharide chains are attached t...
Structural studies on equine glycoprotein hormones. Amino acid sequence of equine lutropin beta-subunit. The amino acid sequence was determined for equine lutropin beta (eLH beta). Large fragments were derived from reduced, carboxymethylated eLH beta by digestion with Staphylococcus aureus V8 protease, by cyanogen bromide cleavage, and by cleavage of acid-labile Asp-Pro bonds. The fragments were purified by gel filtration and high performance liquid chromatography (HPLC). The fragments were sequenced by automated Edman degradation to establish the primary structure of eLH beta. Some peptides were further digested with chymotrypsin and the resulting peptides purified by HPLC. In addition to sequen...
Isolation and characterization of two protamines St1 and St2 from stallion spermatozoa, and amino-acid sequence of the major protamine St1. Two protamines, St1 and St2, were isolated from stallion sperm nuclei, where they represent about 75 and 25%, respectively, of the total basic protein complement. The primary structure of protamine St1 (49 residues; Mr approximately equal to 6600) has been determined. The structure of this protamine is compared to the amino-acid sequence of other mammalian protamines already known.
Synthesis and absorption of cysteine from the hindgut of the horse. The extent to which cysteine synthesised by microbes within the hindgut of the horse is incorporated into plasma cysteine was estimated by an isotopic technique in two horses fed four different diets. The results showed that between 1 per cent and 6 per cent of the plasma cysteine was of microbial origin. It is argued that the maximum contribution of microbial cysteine, and presumably other amino acids of microbial origin, to the plasma pool is 12 per cent of the net supply. These data support the hypothesis that microbial amino acid synthesis within the hindgut of the horse does not significa...
Spectrofluorimetric study of the bile salt micelle binding site of pig and horse colipases. Pig and horse colipases contain three tyrosine residues. In addition, horse colipase possesses a tryptophan residue. Some of the tyrosine residues are involved in the association of colipase and a bile salt micelle. The present report demonstrates that the aromatic residues responsible for colipase fluorescence are in an aqueous environment. In the presence of bile salt micelles, changes in colipase fluorescence properties indicate that the intrinsic fluorophores are located in a more hydrophobic environment upon colipase-micelle complex formation. In addition, the fluorescence of an NBD group...
Effect of meal schedules and fasting on selected plasma free amino acids in horses. The effects of meal frequency and fasting on selected plasma free amino acids (PFAA) was studied in horses. Six 22-mo-old Quarter Horses were used in a replicated 3 X 3 Latin-square design in which each horse received one meal per day (1M), two meals per day (2M) or six meals per day (6M) for 2 wk. A complete pelleted ration was fed at a rate of 1.75% of body weight daily. The consumption of a meal by the horses fed 1M and 2M daily was followed by an increase (P less than .05) in plasma methionine. The highest levels were observed at 5 h and 3 h in the 1M and 2M treatments, respectively. The h...
Purification and characterization of equine relaxin. It has been previously determined that the equine placenta is the sole significant source of relaxin during pregnancy and that relaxin immunoactivity is also present in term placentas. Therefore, placentas obtained at the time of foaling were selected for starting material for purification of equine relaxin. Frozen whole placentas were ground and then extracted with 0.5 N HCl-85% acetone. Relaxin was precipitated by raising the acetone concentration to 97%. Equine relaxin was further purified by stepwise elution ion exchange, gel filtration, and gradient elution ion exchange chromatographies a...
The equine protease inhibitory system (Pi): abnormal expressions of PiF, PiL, and PiS1. Three cases of abnormal expression of the equine protease inhibitory alleles, Pi F, L, and S1, were observed following the examination of 30,000 plasma samples by one-dimensional acid (pH 4.6) polyacrylamide gel electrophoresis. Characterization of the abnormal proteins in terms of isoelectric point, molecular mass, inhibitory spectra, and sialic acid content was performed using one- and two-dimensional electrophoretic techniques. The Pi F and S1 abnormalities were postulated to be the result of amino acid substitutions causing alterations in the processing of the carbohydrate side chains. No ...
Occurrence and distribution of 5-S-cysteinyl derivatives of dopamine, dopa and dopac in the brains of eight mammalian species. The 5-S-cysteinyl derivatives of dopamine, dopa (3,4-dihydroxyphenylalanine) and dopac (3,4-dihydroxyphenylacetic acid) were synthesized and used as reference compounds in high performance liquid chromatography analyses of extracts from various brain regions of eight mammalian species. All three metabolites were detected in the brains of all the species studied. The regional distribution of the metabolites was similar to that of dopamine; the metabolite concentrations ranged from less than 0.1 percent to more than 1 percent of the dopamine level, the highest ratios generally being found in sub...
A study on the role of evolutionarily invariant leucine 32 of cytochrome c. To investigate the role of evolutionarily invariant leucine 32 of horse cytochrome c, analogs of residues 28-38, (28-38), each containing a substituted amino acid at positions 32 or 35 were synthesized using Merrifield's method. Position 35 is leucine in horse cytochrome c but replaced by nonpolar amino acids in some species. The ability of the analogs to bind to the two-fragment complex of ferri- or ferro heme fragment (1-25)H and apofragment (39-104) was measured using gel filtration and equilibrium dialysis. Replacement of leucine 32 with isoleucine, for example, increased the dissociation ...
Nitrogen utilization in bacterial isolates from the equine cecum. A total of 114 bacterial isolates were obtained from the cecal contents of two mature cecally fistulated horses on a habitat-simulating medium containing 40% energy-depleted cecal fluid. Of these isolates, 108 were maintained in pure cultures and were tentatively grouped on the basis of cell morphology and physiological characteristics. Gram-negative rods (50.9%), gram-positive rods (22.8%), and gram-positive cocci (21.9%) represented the largest groups isolated from these animals. Fifty isolates were tested for their ability to grow in media containing urea, ammonia, peptones, or amino acids ...
Mammalian ribonucleases. The absence of a glycosylated Asn-Pro-Thr sequence in horse ribonuclease and the presence of tryptophan at position 39 in horse and dromedary ribonuclease. Parts of the amino acid sequences of horse and dromedary pancreatic ribonuclease were reinvestigated. The sequence of residues 21-25 in horse ribonuclease is Ser-Asn-Pro-Thr-Tyr or Ser-Asn-Ser-Thr-Tyr. The asparagine in the latter sequence is glycosylated. Horse ribonuclease possesses four additional amino acid residues at the C-terminus, like a number of other ribonucleases. Position 39 in horse and dromedary ribonuclease is not deleted but is occupied by tryptophan.
Breed and species comparison of amino acid transport variation in equine erythrocytes. The amino acid permeability of red blood cells from Equus caballus (thoroughbred, Arab, shire and pony), E przewalskii (Przewalski's horse), E asinus (donkey and mule) and E burchelli (common or plains zebra) was measured. Individual animals exhibited stable but widely differing rates of L-[U-14C]alanine uptake in the range 5 to 1554 mumol (litre cells)-1 h-1 (0.2 mM extracellular L-alanine, 37 degrees C). Of the thoroughbreds tested, 30 per cent had red blood cells which were essentially impermeable to L-alanine (5 to 10 mumol (litre cells)-1 h-1, giving transport rates similar to those found...
Characterization of a novel Na+-independent amino acid transporter in horse erythrocytes. Horse erythrocytes are polymorphic with respect to L-alanine permeability. The present investigation compared the specificity, kinetics and cation-dependence of erythrocyte amino acid transport in two groups of thoroughbred horses, those with erythrocyte L-alanine permeabilities in the range 5-15 mumol/h per litre of cells (0.2 mM extracellular L-alanine, 37 degrees C) (transport-negative type) and those with L-alanine permeabilities in the range 450-700 mumol/h per litre of cells (transport-positive type). Transport-positive cells are shown to possess a novel high-affinity, stereospecific, Na...
Antigenic determinants of acylphosphatase from porcine skeletal muscle. Analysis of the quantitative precipitin reaction of acylphosphatase from porcine skeletal muscle with rabbit antiserum indicated the presence of at least two antigenic determinants on the porcine enzyme molecule. Immunological cross-reactivities of acylphosphatases from equine and rabbit skeletal muscles were examined. In double immunodiffusion with the antiserum, the precipitin lines of the porcine and equine enzymes completely fused, while the rabbit enzyme gave no precipitin line. The reaction between the 125I-labeled porcine enzyme and its antibody was inhibited to the same extent by the p...
Characteristics of Mycoplasma strains isolated from stallion semen. Eleven mycoplasma strains were isolated from the semen of 24 stallions. Eight of these strains were identified as Mycoplasma equigenitalium. Three strains which hydrolized arginine could not be identified. The growth inhibition test with immune sera against M. arginini and M. equirhinis was negative. Antibiotic sensitivity test showed that all strains were sensitive to four antibiotic of tetracycline group (oxytetracyclin, minocycline, transcycline and vibramycin). Lincomycin and gentamycin appeared to be the most active against all the strains. Comparative analysis of routine semen examinatio...
Obtaining of pure transferrins D, M and R from equine serum and determination of transferrin level in relation to phenotype. By the method of precipitation with Rivanol (2-ethoxy-6,9-diaminoacridine lactate) and ammonium sulphate followed by chromatography on DEAE cellulose three genetic variants of transferrin were purified from equine serum: D, M and R. Their molecular mass determined in this study was 80 000, and it was identical for all three variants, which differed slightly in their amino acid composition. The protein level was determined in the serum of 535 two-year-old thoroughbred English horses by the method of rocket immunoelectrophoresis using antibodies obtained against three transferrins. The individua...
Partial amino-acid sequence and cysteine reactivities of cytosolic aspartate aminotransferase from horse heart. Cytosolic aspartate aminotransferase (L-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1) from horse heart has five cysteine residues, two of which can be titrated with 5,5'-dithiobis(2-nitrobenzoid acid) in the native enzyme with no impairment of catalytic activity. The rate of modification is unaffected by the presence of substrates. Reaction with N-ethylmaleimide leads to loss of catalytic activity, the rate of inactivation being increased by the presence of substrates. Peptides containing 361 amino-acid residues (about 88% of the total number in the protein) have been isolated and ali...
[Multiple forms of horse pepsin]. Using ion-exchange and affinity chromatography and isoelectrofocusing, eight forms of pepsin with pI 1.6, 1.8, 2.1, 2.3, 2.6, 2.8, 3.2 and 3.6, were isolated from horse gastric juice. The molecular weights, amino acid composition, N-terminal sequence and functional activity of these multiple forms were determined. Partial primary structure of tryptic peptides of pepsin with pI 2.3 was investigated. The analyzed partial sequences of the forms with pI 1.8, 2.1, 2.3, and 2.6 have identical structures which differ from the amino acid sequence of pepsin with pI 3.2 by four substituents. In terms of...
Blood metabolite profiles of broodmares and foals. Serum amino acid profiles and other serum characteristics of broodmares and their foals wee studied. Compared with mares, foals had significantly higher concentrations of serum leucine, threonine, aspartic acid, asparagine, glutamic acid, glutamine, proline and tyrosine, glucose, cholesterol, creatinine and phosphorus. Foals had significantly less serum histidine, glycine, cystine, taurine, protein and urea nitrogen. Lysine and/or methionine supplementation of pregnant and lactating broodmare diets were conducted. Changes in serum amino acid profiles caused by dietary amino acid supplemented w...
Effects of dietary supplementation with butylated hydroxyanisole, cysteine, and vitamins B on tansy ragwort (Senecio jacobaea) toxicosis in ponies. Dried tansy ragwort, which contains pyrrolizidine alkaloids, was fed as 10% of a complete diet to ponies, with and without a mixture of additives. The additives provided a dietary supplement equivalent to 1% cysteine, 0.75% butylated hydroxyanisole, 200 micrograms of vitamin B12/kg of feed, and 5 mg of folic acid/kg of feed. The additives did not alter tansy ragwort toxicity, as assessed by survival time, liver changes, sulfobromophthalein (BSP) clearance rate, serum gamma-glutamyl transpeptidase activity, and plasma amino acid patterns. In ponies fed tansy ragwort, BSP clearance rate was a se...
Characterisation of glycoproteins in the sweat of the horse (Equus caballus). The two major polypeptides H (Mr 49,000) and L (Mr 33,000) of equine sweat have been purified by gel filtration and characterised by gel electrophoresis and compositional analysis. Both H and L are glycoproteins containing sialic acid, neutral sugars, N-acetylglucosamine and N-acetylgalactosamine, but the two polypeptides differ considerably in the extent of glycosylation. H and L also differ in amino acid composition, but both contain only low levels of sulphur containing amino acids and histidine. These glycoproteins may behave as surfactants.
Difference in sizes of human compared to murine alpha-subunits of the glycoprotein hormones arises by four-codon gene deletion or insertion. The sizes of the human and subhuman alpha-subunits of the glycoprotein hormones differ by four amino acids (hCG alpha, 92 amino acids; murine, equine, bovine, and ovine alpha, 96 amino acids). The shortening of the human alpha-subunit has been attributed to posttranslational proteolysis. We have recently determined the nucleotide sequences of the mRNAs encoding the precursors of the alpha-subunit of mouse TSH and rat gonadotropins using recombinant DNA techniques. In this report, we have compared these nucleotide sequences and their deduced amino acid sequences with those of the pre- alpha-sub...
Studies on prolactin 48: isolation and properties of the hormone from horse pituitary glands. Isolation of prolactin from equine pituitary glands has been described. It has a potency of 42 IU/mg in the pigeon crop-sac test and consists of 199 amino acids. The hormone has only four half-cystine residues in contrast to other mammalian prolactins which have six residues. From NH2-terminal sequence analysis and amino acid composition of cyanogen bromide fragments, the NH2-terminal disulfide loop is missing in the equine prolactin molecule. Circular dichroism spectra indicate that the alpha-helical content of equine prolactin appears to be lower (50%) than that found in the ovine hormone (6...
Structural and functional properties of the non-muscle tropomyosins. The non-muscle tropomyosins (TMs), isolated from such tissues as platelets, brain and thyroid, are structurally very similar to the muscle TMs, being composed of two highly alpha-helical subunits wound around each other to form a rod-like molecule. The non-muscle TMs are shorter than the muscle TMs; sequence analysis demonstrates that each subunit of equine platelet TM consists of 247 amino acids, 37 fewer than for skeletal muscle TM. The major differences in sequence between platelet and skeletal muscle TM are found near the amino and carboxyl terminal ends of the proteins. Probably as the re...
Resonance-enhanced Raman identification of a ternary chemical intermediate during the equine liver alcohol dehydrogenase reduction of p-(dimethylamino)benzaldehyde. 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, ...
Protein utilisation in response to caecal corn starch in ponies. 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...
Systemic d-phenylalanine and d-leucine for effective treatment of pain in the horse. This study showed that subcutaneous injection of a solution of D-amino acids produced effective analgesia in horses. It is postulated that systemic D-phenylalanine and D-leucine may become one of the safe, effective and nonaddictive drugs for acute and chronic pain treatment. These D-amino acids cause analgesia by presumably preserving brain endorphins. They may bind reversibly to enkephalinases and prevent enzymatic degradation of enkephalins.
Lysine supplementation of diets for yearling horses. Forty-six Thoroughbred and Quarter Horse yearlings were used in two experiments designed to determine the amount of lysine in the concentrate necessary to promote maximum growth when fed the Coastal bermudagrass (Cynodon dactylon) hay provided at 1% body weight (BW)/day. In the first experiment, a 196-day trial, supplemental protein sources and analyses of the concentrates compared were: (1) soybean meal (SBM; 15.4% crude protein, .70% lysine); (2) SBM + .2% lysine (15.7% crude protein, .81% lysine), and (3) brewers dried grains + .2% lysine (15.9% crude protein, .59% lysine). Concentrate inta...
