Topic:Molecular biology
Molecular biology in horses involves the study of molecular processes and genetic mechanisms that underpin equine physiology and health. This field encompasses the analysis of DNA, RNA, proteins, and other biomolecules to understand gene expression, genetic variation, and cellular functions in horses. Techniques such as genomic sequencing, gene expression profiling, and molecular diagnostics are employed to explore topics like hereditary diseases, performance traits, and immune responses in equines. This page assembles peer-reviewed research studies and scholarly articles that investigate the molecular biology of horses, focusing on genetic research, molecular techniques, and their applications in equine science.
Radioimmunological measurement of beta-endorphin in equine plasma. Radioimmunoassay procedures were developed and validated for the quantification of beta-endorphin (beta-EP)-like immunoreactivity in equine plasma. beta-EP could be quantitatively extracted from plasma with silicic acid powder and subsequently assayed, however, valid estimates of this hormone could also be obtained on unextracted plasma. Although beta-lipotropin (beta-LPH) cross-reacted in the assay, it was not necessary to correct for beta-LPH activity when assaying unextracted plasma because chromatographic analyses showed that 92% of the immunoreactivity in plasma extracts was similar in mo...
Characteristics of receptors for prostaglandin F-2 alpha in bovine and equine corpora lutea. Prostaglandin F-2 alpha (PGF-2 alpha) receptors of bovine and equine corpora lutea (C.L.) were studied. From both the equilibrium binding data and the dissociation kinetics behaviour, two affinity classes of receptors are evident in the mare, with apparent dissociation constants (Kd) of 1,5 x 10(-9) M and 3.5 x 10(-8) M. Bovine PGF-2 alpha receptors present a homogeneous population of binding sites with Kd = 1 x 10(-8) M. Both bovine and equine C.L. receptors bind PGF-2 alpha in a specific manner; only 13, 14-dihydro-PGF-2 alpha considerably cross-reacts with these receptors. Since in the mare...
[Study of conformational changes in alcohol dehydrogenase during its interaction with silochrome adsorbent by the EPR spectroscopy method]. The possible use of EPR spectroscopy (spin labelling) for the study of horse liver alcohol dehydrogenase with a silochrome adsorbent is discussed. The rotatory diffusion of nitroxyl labels chemically linked to the enzyme was studied with reference to the time of the enzyme incubation with the adsorbent and the degree of its accumulation on the adsorbent surface. The mobility of nitroxyl radicals attached to the protein globules was shown to increase with time. It was concluded that the conformation of the enzyme molecules changes during their interaction with the adsorbent.
Localization of the second calcium ion binding site in porcine and equine phospholipase A2. At alkaline pH porcine pancreatic phospholipase A2 is known to bind two Ca2+ ions per protein molecule. One Ca2+ ion is strongly bound to the active site and is essential for enzyme activity. A second Ca2+ ion binds more weakly to the protein and improves the affinity of the enzyme for lipid-water interfaces severalfold at high pH values. A group having a pK around 6 controls enzyme binding to lipid-water interfaces in the absence of Ca2+. By use of proton titration techniques this group is now identified to be a carboxylate having an abnormally high pK. Its pK shifts to a value around 4.5 in ...
Selective crystallization of horse isoferritins. Various precipitating agents were examined in order to crystallize horse heart and spleen ferritins. Cadmium sulfate induced the crystallization of the spleen ferritin, while 2-methyl-2,4-pentanediol and poly(ethylene glycol) only induced that of the heart ferritin. Isoelectric focusing analysis showed that the crystals grown from cadmium sulfate contained only the more acidic isoferritins, and those grown from methyl pentanediol only the less acidic isoferritins. Heart ferritin crystallizes in a cubic space group, as previously reported for spleen ferritin crystals grown from cadmium sulfate....
Synthesis and properties of equine beta-melanotropin analogs with substitution in residue position 1. Five analogs of equine β-melanotropin have been synthesized by the solid phase method. The NH2-terminal aspartic acid was substituted with amino acids (Gly, Trp, Ile, Lys and Nα-acetyl-Asp) differing widely in physicochemical properties. On the basis of their lipolytic potencies it was concluded that this position plays a negligible role in this activity.
Use of procainamide gels in the purification of human and horse serum cholinesterases. Two large-scale methods based primarily on the use of procainamide-Sepharose gels were developed for the purification of horse and human serum non-specific cholinesterases. With method I, the procainamide-Sepharose 4B gel was used in the first step to handle large volumes of serum. With method II, the procainamide-Sepharose 4B gel was used in the final step to obtain pure enzyme. Although both methods gave electrophoretically pure cholinesterase preparations in good yields, they were significantly more efficient at purifying the horse enzyme than the human enzyme. To study this problem, the re...
A comparative study of the effect of triazine herbicides on alcohol dehydrogenases isolated from various sources. The studied herbicides (terbutylazine, simazine) inhibit the activity of plant, animal, and yeast alcohol dehydrogenases. The inhibition constant Ki for alcohol dehydrogenase (ADH) isolated from peas and bakers' yeast equals approximately 10(-4) M, and that for ADH isolated from horse liver is of the order of 10(-5) M. The character of inhibition for all the herbicides studied for the reaction catalyzed by pea, liver, and yeast ADH is always noncompetitive toward ethanol and competitive with respect to NAD. The inhibition constants for the enzyme isolated from peas are pH independent. The inte...
The genetic control of antibody formation. Studies of the molecular biology of lymphoid cells have markedly increased our understanding of how millions of different antibodies can be synthesized by a single animal. To date, the most detailed understanding has been achieved for the mouse, primarily because of the relatively greater experimental availability of this species. These studies, as well as those involving other species, have shown that the complete genes for antibody polypeptide chains are assembled from disparate genetic elements which are originally widely separated in the genome. The assembly process itself, together with t...
Dansylarginine N-(3-ethyl-1.5-pentanediyl)amide. A potent and selective fluorescent inhibitor of butyrylcholinesterase. Interactions between dansylarginine N-(3-ethyl-1,5-pentanediyl)amide (DAPA) and the cholinesterases were examined by the techniques of enzyme kinetics and fluorescence spectroscopy. When tested with partially purified enzyme preparations, DAPA was a potent inhibitor of butyrylcholinesterase (IC50 = 2 x 10(-7) M) but not of acetylcholinesterase (IC50 = 4 x 10(-4) M). For a detailed study of the effects of DAPA on butyrylcholinesterase (BuChE), the enzyme was purified to homogeneity from horse serum, with the aid of affinity chromatography on N-methyl acridinium. The kinetics of the inhibition o...
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...
Further study of the chemical structure of the equine erythrocyte hematoside containing O-acetyl ester. The chemical structure of an equine hematoside, which contained an ester group and comprised 72% of the total erythrocyte gangliosides, was determined by means of nondestructive and destructive procedures. A 400-MHz nuclear magnetic resonance spectrum of the ganglioside in perdeuterodimethyl sulfoxide demonstrated three protons due to a methyl group of an acetyl moiety, as well as amide and anomeric protons which were compatible with those of the ordinary hematoside. The spin decoupling difference spectroscopy of the ganglioside revealed the presence of the following structures. [formula: see ...
Effects of common radioiodination procedures on the binding of glycoproteins to immobilized lectins. Representative glycoproteins including fetuin, protein A, ovalbumin, alpha 1 acid glycoprotein, and the major glycoprotein of equine infectious anemia virus were labelled with 125I by the chloramine-T or Bolton-Hunter procedure and their binding to immobilized Con A or lentil lectin compared to untreated samples of each glycoprotein. Glycoprotein modification was no greater than one substituted residue per protein molecule. Yet the radioiodinated glycoproteins typically displayed only 0-50% of the lectin binding observed with untreated samples. These results indicate that lectin glycoprotein b...
Intestinal alkaline phosphatase-like properties of horse kidney alkaline phosphatase. Two isoenzymes of alkaline phosphatase from horse kidney were identified by cellulose acetate electrophoresis. Horse kidney alkaline phosphatase was similar to horse intestinal alkaline phosphatase, in regard to both antigenicity and response to levamisole inhibition, but different from horse liver alkaline phosphatase. This study suggests that horse kidney alkaline phosphatase is an expression of the intestinal gene locus and not the hepatic gene locus.
Identification of the second alpha-2-antiprotease of equine serum as antithrombin III. The alpha-2-protease inhibitor, of 65,000 daltons molecular weight, described by several authors in horse plasma and also present as a contaminant in alpha-1-isoinhibitor isolates previously described by us (Pellegrini & von Fellenberg (1980) Biochim. biophys. Acta 616, 351-361) has now been isolated to purity and identified as antithrombin III. The inhibitor is composed of a single polypeptide chain as judged by SDS polyacrylamide gel electrophoresis. The inhibitor was effective only against trypsin and thrombin. Serological cross-reaction existed between the inhibitor and the antiserum t...
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...
Characterisation of the alpha 1-protease inhibitor system in Thoroughbred horse plasma by horizontal two-dimensional (ISO-DALT) electrophoresis. 1. Protein staining. The isoelectric points and the molecular weights of the major components of the eight Thoroughbred protease inhibitor (Pi) types have been determined by polyacrylamide gel isoelectric focusing and polyacrylamide gel pore gradient (ISO-DALT) electrophoresis respectively. The major Pi proteins focus in the range pH 3.74-4.43 and have molecular weights ranging from 55 000-72 000 daltons. Using the ISO-DALT method of electrophoresis, protein maps for the eight Thoroughbred Pi types have been presented for the first time. None of the homozygous Pi types are identical except for the types S1 and S2 ...
Genetic linkage between the loci for phosphohexose isomerase (PHI) and a serum protein (Xk) in horses. Genetic linkage between the equine loci for phosphohexose isomerase (PHI) and serum Xk protein was demonstrated by means of segregation data from three sire families. The recombination frequency was estimated from pooled data to be 0.23 +/- 0.02; a significant heterogeneity between sires for estimates of the recombination frequency was observed. No indication of linkage was detected between Xk and 14 other blood marker loci. Linkage between the Xk locus and the locus for soluble malic enzyme (ME1) has recently been reported in horses. An equine linkage group designated LG IV comprising the thr...
Subcellular localization and properties of the NAD(P)H oxidase from equine polymorphonuclear leukocytes. The subcellular distribution of the superoxide-forming enzyme in horse polymorphonuclear leukocytes was investigated. After activation of the cells with sodium oleate, a relatively stable and NAD(P)H-dependent oxygen consumption and superoxide production was found in association with the plasma membranes. The pH dependence displayed an optimum near neutrality. The apparent Km values were 38 x 10(-6) mol/l for NADPH and 1,560 x 10(-6) mol/l for NADH, suggesting that NADPH is the physiological donor. The rates of oxygen uptake, O2- production, and NADP consumption were consistent with the stoich...
Isolation and characterization of horse alpha 2-macroglobulin protease inhibitor. Several publications have described in the past properties of partly purified horse alpha 2-macroglobulin (alpha 2M) which are strikingly different from the human alpha 2M. Horse alpha 2M was therefore isolated to purity by classical procedures, i.e. affinity chromatography, ion exchange chromatography and gel filtration, and its properties are compared with those of its human counterpart. The molecular weight of the native protein and its subunits, the isoelectrofocusing pattern and the change in electrophoretic mobility caused by interaction with protease were similar to those of human alpha...
Kinetic and structural relationships of transition monomeric and oligomeric carboxyl- and choline-esterases. The kinetic and structural relationships of eight electrophoretically pure mammalian serum and liver serine carboxylesterases (CE) and cholinesterases (ChE) have been studied. Eight CE's and ChE's, which were fully resolved but only partially purified, provided additional information. Five of the electrophoretically pure esterases were monomeric, and of these, four belonged to a new and widely distributed class. These four monomeric esterases hydrolyzed choline esters, but at widely differing rates. Thus two were termed monomeric butyrylcholinesterases, mBuChE I and II, and two were monomeric ...
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...
Pyrimidine metabolism in peripheral and phytohemagglutinin-stimulated mammalian lymphocytes. 1. Activity of uridine kinase was very low in ovine lymphocytes and in those of some pigs. Lymphocytes of other pigs showed a significantly higher activity of this enzyme. Activity of uridine kinase in lymphocytes of man, horse and cattle was intermediate. 2. Activity of uridine phosphorylase was higher than that of uridine kinase with lymphocytes of all species. 3. Activity of uridine kinase in equine lymphocytes increases at PHA-stimulation and also in porcine lymphocytes with a low activity at the start of the culture. Activity of uridine kinase decreased in porcine lymphocytes with a high ...
Streptokinase-dependent delayed activation of horse plasminogen. 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...
Characterization of the major antigens of Haemophilus equigenitalis (contagious equine metritis organism). 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...
The use of capillary column gas chromatography and negative ion chemical ionization mass spectrometry to confirm the administration of synthetic corticosteroids to horses. The negative ion chemical ionization mass spectra of the MO-TMS derivatives of the corticosteroids prednisolone, betamethasone and dexamethasone have been obtained using capillary column gas chromatography mass spectrometry. The spectra showed abundant diagnostic ions at m/z greater than 300 allowing for clear discrimination between the three steroid derivatives. A capillary column gas chromatographic mass spectrometric method using negative ion chemical ionization mass spectrometry has been developed to confirm the presence of the parent steroids in horse urine following the administration of...
Estrogens in seminal plasma of human and animal species: identification and quantitative estimation by gas chromatography-mass spectrometry associated with stable isotope dilution. Estrone, 2-methoxyestrone and estradiol-17 beta have been definitely identified in seminal plasma of man, bull, boar and stallion by high resolution gas chromatography associated with selective monitoring of characteristic ions of suitable derivatives. Quantitative estimations were performed by isotope dilution with deuterated analogues and by monitoring molecular ions of trimethylsilyl ethers of labelled and unlabelled compounds. Concentrations of unconjugated and total estrogens are reported together with the statistical evaluation of accuracy and precision.
[Some physicochemical properties of native and polymerized glutaraldehyde-treated horse heart cytochrome c]. 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...
Purification and identification of horse serum IgA. ウマ分泌型IgA (初乳, 涙) の分離精製については, すでに報告されているが, ウマ血清IgAの分離精製に関する明確な手法を示した報告は見あたらない. われわれは, ウマ血清を脱塩, 硫安塩析し, ついでDEAEセルロース, 免疫吸着体のカラム操作により, 抗原性および分子サイズにおいて, IgG, IgG(T), IgM とは明らかに区別される免疫グロブリンを分離精製した. この免疫グロブリンは抗イヌIgAとの交差反応性により, IgAと同定された. さらに作製した抗分泌型...