Thyroidal iodine metabolism in obese-strain chickens before immune-mediated damage

1991 ◽  
Vol 128 (2) ◽  
pp. 239-NP ◽  
Author(s):  
R. S. Sundick ◽  
D. Herdegen ◽  
T. R. Brown ◽  
A. Dhar ◽  
N. Bagchi

ABSTRACT Several studies have shown that iodine plays a role in spontaneous autoimmune thyroiditis in man and other animals. In addition, abnormalities of iodine metabolism have been found in patients with Hashimoto's thyroiditis and in chickens of the obese strain (OS), an animal model of spontaneous autoimmune thyroiditis. We have examined several parameters of iodine metabolism before immune damage in this model and in the related Cornell strain (CS), a strain which develops a late-onset mild thyroiditis, to discover a possible causal relationship between altered iodine metabolism and the initiation of autoimmunity. Thyroglobulin was purified from individual chicken thyroid glands and analysed for iodine by the ceric sulphate method. Analogous to the thyroglobulin of Hashimoto's patients, the iodine content of OS thyroglobulin (27 atoms/molecule) was lower than that of normal-strain thyroglobulin (46 atoms/molecule) when the chickens were provided with a normal diet. Also, under conditions of TSH suppression, the iodine content of OS thyroglobulin (18 atoms/molecule) was lower than that of CS thyroglobulin (36 atoms/molecule) and of normal-strain thyroglobulin (32 atoms/molecule). In contrast with Hashimoto's patients, however, the OS and CS chickens had practically no inorganic iodide in their thyroid glands; electrophoretic analysis of thyroid homogenates revealed that essentially all (> 99·62%) 125I was organified by 16 h in all strains of birds tested. Despite the relatively poor iodination of thyroglobulin exhibited by OS chickens, they did not iodinate additional 'unique' proteins, when examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of thyroid proteins labelled with 125I in vivo. The release of 125I in vivo under conditions of TSH suppression was examined in chicks receiving thyroxine and propylthiouracil. After 14 days both OS and CS chicks showed poorly suppressible release of 85% and 92% respectively, while the normal strain released 33 %. To determine whether the autonomous function of OS and CS thyroid glands was present in a restricted number of follicles or cells or whether it occurred in a majority of cells, autoradiograms of thyroid glands labelled in vivo from TSH-suppressed chickens were examined. Silver grains were present in all cells, indicating that autonomous function was a characteristic of all cells. These thyroid gland abnormalities are compared with those found in Hashimoto's patients and discussed in the context of their aetiological significance. Journal of Endocrinology (1991) 128, 239–244

1990 ◽  
Vol 258 (2) ◽  
pp. C344-C351 ◽  
Author(s):  
H. Schmidt ◽  
G. Wegener

White skeletal muscle of crucian carp contains a single isoenzyme of glycogen phosphorylase, which was purified approximately 300-fold to a specific activity of approximately 13 mumol.min-1.mg protein-1 (assayed in the direction of glycogen breakdown at 25 degrees C). Tissue extracts of crucian muscle produced three distinct peaks of phosphorylase activity when separated on DEAE-Sephacel. Peaks 1 and 3 were identified, in terms of kinetic properties and by interconversion experiments, as phosphorylase b and a, respectively. Peak 2 was shown to be a phospho-dephospho hybrid. The three interconvertible forms of phosphorylase were purified and shown to be dimeric molecules at 20 degrees C. At 5 degrees C, a and the hybrid tended to form tetramers. The Mr of the subunit was estimated to be 96,400 from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hybrid is kinetically homogeneous, and its kinetic properties are intermediate between those of b and a forms. The b, hybrid, and a forms of phosphorylase can be isolated from rapidly frozen muscle of crucian but in different proportions, depending on whether fish were anesthetized or forced to muscular activity for 20 s. Muscle of anesthetized crucian had 36, 36, and 28% of phosphorylase b, hybrid, and a forms, respectively, whereas the corresponding values for exercised fish were 12, 37, and 51%. Results suggest that three interconvertible forms of phosphorylase exist simultaneously in crucian muscle and that hybrid phosphorylase is active in contracting muscle in vivo.


1998 ◽  
Vol 66 (9) ◽  
pp. 4374-4381 ◽  
Author(s):  
John C. McMichael ◽  
Michael J. Fiske ◽  
Ross A. Fredenburg ◽  
Deb N. Chakravarti ◽  
Karl R. VanDerMeid ◽  
...  

ABSTRACT The UspA1 and UspA2 proteins of Moraxella catarrhalisare potential vaccine candidates for preventing disease caused by this organism. We have characterized both proteins and evaluated their vaccine potential using both in vitro and in vivo assays. Both proteins were purified from the O35E isolate by Triton X-100 extraction, followed by ion-exchange and hydroxyapatite chromatography. Analysis of the sequences of internal peptides, prepared by enzymatic and chemical cleavage of the proteins, revealed that UspA1 and UspA2 exhibited distinct structural differences but shared a common sequence including an epitope recognized by the monoclonal antibody 17C7. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), purified UspA1 exhibited a molecular weight of approximately 350,000 when unheated and a molecular weight of 100,000 after being heated for 10 min at 100°C. In contrast, purified UspA2 exhibited an apparent molecular weight of 240,000 by SDS-PAGE that did not change with the length of time of heating. Their sizes as determined by gel filtration were 1,150,000 and 830,000 for UspA1 and UspA2, respectively. Preliminary results indicate the proteins have separate functions in bacterial pathogenesis. Purified UspA1 was found to bind HEp-2 cells, and sera against UspA1, but not against UspA2, blocked binding of the O35E isolate to the HEp-2 cells. UspA1 also bound fibronectin and appears to have a role in bacterial attachment. Purified UspA2, however, did not bind fibronectin but had an affinity for vitronectin. Both proteins elicited bactericidal antibodies in mice to homologous and heterologous disease isolates. Finally, mice immunized with each of the proteins, followed by pulmonary challenge with either the homologous or a heterologous isolate, cleared the bacteria more rapidly than mock-immunized mice. These results suggest that UspA1 and UspA2 serve different virulence functions and that both are promising vaccine candidates.


1983 ◽  
Vol 59 (1) ◽  
pp. 81-103 ◽  
Author(s):  
R. Crossley ◽  
D.V. Holberton

Proteins from the axonemes and disc cytoskeleton of Giardia lamblia have been examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. In addition to tubulin and the 30 X 10(3) molecular weight disc protein, at least 18 minor components copurify with the two major proteins in Triton-insoluble structures. The most prominent minor bands have the apparent molecular weights of 110 X 10(3), 95 X 10(3) and 81 X 10(3). Protein of 30 X 10(3) molecular weight accounts for about 20% of organelle protein on gels. In continuous 25 mM-Tris-glycine buffer it migrates mostly as a close-spaced doublet of polypeptides, which are here given the name giardins. Giardia tubulin and giardin have been purified by gel filtration chromatography in the presence of sodium dodecyl sulphate. Well-separated fractions were obtained that could be further characterized. Both proteins are heterogeneous when examined by isoelectric focusing. Five tubulin chains were detected by PAGE Blue 83 dye-binding after focusing in a broad-range ampholyte gel. Giardin is slightly less acidic than tubulin. On gels it splits into four major and four minor chains with isoelectric points in the pI range from 5.8 to 6.2. The amino acid composition of the giardin fraction has been determined, and compared to Giardia tubulin and a rat brain tubulin standard. Giardins are rich in helix-forming residues, particularly leucine. They have a low content of proline and glycine; therefore they may have extensive alpha-helical regions and be rod-shaped. As integral proteins of disc microribbons, giardins in vivo associate closely with tubulin. The properties of giardins indicate that in a number of respects - molecular size, charge, stoichiometry - their structural interaction with tubulin assemblies will be different from other tubulin-accessory protein copolymers studied in vitro.


1980 ◽  
Vol 189 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Yoav Ben-Yoseph ◽  
Melinda Hungerford ◽  
Henry L. Nadler

Galactocerebrosidase (β-d-galactosyl-N-acylsphingosine galactohydrolase; EC 3.2.1.46) activity of brain and liver preparations from normal individuals and patients with Krabbe disease (globoid-cell leukodystrophy) have been separated by gel filtration into four different molecular-weight forms. The apparent mol.wts. were 760000±34000 and 121000±10000 for the high- and low-molecular-weight forms (peaks I and IV respectively) and 499000±22000 (mean±s.d.) and 256000±12000 for the intermediate forms (peaks II and III respectively). On examination by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the high- and low-molecular-weight forms revealed a single protein band with a similar mobility corresponding to a mol.wt. of about 125000. Antigenic identity was demonstrated between the various molecular-weight forms of the normal and the mutant galactocerebrosidases by using antisera against either the high- or the low-molecular-weight enzymes. The high-molecular-weight form of galactocerebrosidase was found to possess higher specific activity toward natural substrates when compared with the low-molecular-weight form. It is suggested that the high-molecular-weight enzyme is the active form in vivo and an aggregation process that proceeds from a monomer (mol.wt. approx. 125000) to a dimer (mol.wt. approx. 250000) and from the dimer to either a tetramer (mol.wt. approx. 500000) or a hexamer (mol.wt. approx. 750000) takes place in normal as well as in Krabbe-disease tissues.


1985 ◽  
Vol 228 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J C Garcia-Borron ◽  
F Solano ◽  
J L Iborra ◽  
J A Lozano

The purification of two isoenzymes of tyrosinase has been carried out in Harding-Passey mouse melanoma. One is found in the cytosol and the other one bound to melanosomes. Both migrate as single bands on sodium dodecyl sulphate/polyacrylamide gels, having an apparent Mr of 58 000. Solubilized particulate tyrosinase showed an aggregation equilibrium involving a monomer, tetramer, octamer and a high-Mr micellar form with Brij 35, the solubilizing agent. H.p.l.c. studies indicated a interconversion between those species, the monomer contribution increasing with the sample dilution. The tetramer and the octamer probably represent the predominant forms in vivo. Soluble tyrosinase showed a simpler aggregation equilibrium, involving two forms, monomer and tetramer, with the same interconversion pattern. Fluorescence studies suggested that tryptophan residues were exposed to the aqueous environment when tyrosinase was dissociated by dilution. Tyrosinase shows a tendency to aggregate, at low protein concentration, and a resistance to dissociation by urea or SDS so remarkable that gel-permeation chromatography in 4M-urea does not affect the equilibrium, and the band obtained on SDS/polyacrylamide-gel electrophoresis is a dimer.


Blood ◽  
1993 ◽  
Vol 82 (9) ◽  
pp. 2872-2879 ◽  
Author(s):  
SN Georas ◽  
BW McIntyre ◽  
M Ebisawa ◽  
JL Bednarczyk ◽  
SA Sterbinsky ◽  
...  

Abstract The mechanisms responsible for the accumulation of eosinophils at sites of allergic and other inflammatory reactions are unknown, but recent studies have implicated both eosinophil and endothelial adhesion molecules in this process. However, less well studied have been the adhesive interactions between eosinophils and the subendothelial basement membrane and interstitial connective tissues. To test the hypothesis that eosinophils might interact with extracellular matrix proteins, we analyzed purified human eosinophils for the expression and function of various beta 1 integrins. Using indirect immunofluorescence and flow cytometry, purified eosinophils from mildly allergic donors were found to consistently express the integrin subunits beta 1 (CD29), alpha 4 (CD49d, very late activation antigen [VLA]-4 alpha), and alpha 6 (CD49f, VLA-6 alpha). No significant expression of the alpha 1, alpha 2, alpha 3, alpha 5, or beta 4 subunits was detected. Platelet contamination of the eosinophil preparations was excluded by light microscopy and by the inability to detect expression of platelet glycoproteins alpha v, CD41b, and CD42b. Immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of eosinophils confirmed the expression of cell-surface beta 1, alpha 4, and alpha 6. Furthermore, eosinophils purified from allergic donors were shown to adhere to plate-bound laminin, but not to type 1 or type 4 collagen. Adhesion to laminin was concentration-dependent, required divalent cations, and was completely and specifically inhibited by the anti-alpha 6 monoclonal antibody (MoAb) GoH3 and by the anti-beta 1 MoAb 33B6. Interestingly, the anti-beta 1 MoAb 18D3 (which like 33B6 blocks eosinophil binding to VCAM-1) did not inhibit eosinophil adhesion to laminin, suggesting that there are functionally distinct epitopes on the beta 1 subunit. Eosinophils purified from 4 healthy, nonallergic donors also showed alpha 6-dependent adhesion to laminin, although these cells adhered less well. These studies establish the expression of alpha 6 beta 1 on human eosinophils and document its function as a laminin receptor. Interaction of eosinophil alpha 6 beta 1 with laminin, eg, in basement membranes, may contribute to the localization of these cells at inflammatory sites in vivo.


2003 ◽  
Vol 71 (7) ◽  
pp. 3794-3801 ◽  
Author(s):  
Tatiana D. Sirakova ◽  
Vinod S. Dubey ◽  
Hwa-Jung Kim ◽  
Michael H. Cynamon ◽  
Pappachan E. Kolattukudy

ABSTRACT The cell wall lipids in Mycobacterium tuberculosis are probably involved in pathogenesis. The largest open reading frame in the genome of M. tuberculosis H37Rv, pks12, is unique in that it encodes two sets of domains needed to produce fatty acids. A pks12-disrupted mutant was produced, and disruption was confirmed by both PCR analysis and Southern blotting. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that a 430-kDa protein band present in the wild type was missing in the mutant. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MS) and liquid chromatography (LC)-MS analysis of tryptic peptides showed that 54 peptides distributed throughout this protein matched the pks12-encoded sequence. Biochemical analysis using [1-14C]propionate as the radiotracer showed that the pks12 mutant was deficient in the synthesis of dimycocerosyl phthiocerol (DIM). SDS-PAGE, immunoblot analysis of proteins, and analysis of fatty acids showed that the mutant can produce mycocerosic acids. Thus, the pks12 gene is probably involved in the synthesis of phthiocerol, the diol required for DIM synthesis. Growth of the pks12 mutant was attenuated in mouse alveolar macrophage cell line MH-S, and the virulence of the mutant in vivo was highly attenuated in a murine model. Thus, pks12 probably participates in DIM production and its expression is involved in pathogenesis.


1981 ◽  
Vol 195 (1) ◽  
pp. 267-275 ◽  
Author(s):  
M Mantle ◽  
A Allen

Glycoprotein from pig small-intestinal mucus was isolated free of non-covalently bound protein and nucleic acid with a yield of over 60%. No non-covalently bound protein could be detected by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis or by equilibrium centrifugation in a density gradient of CsCl with 4 M-guanidinium chloride. The intrinsic viscosity and reduced viscosity of the glycoprotein preparations rose with the removal of non-covalently bound protein and nucleic acid from the glycoprotein, evidence that non-covalently bound protein does not contribute to the rheological properties of the glycoprotein in the mucus. The pure glycoprotein, in contrast with impure preparations, gelled at the same concentration of glycoprotein as that present in the gel in vivo. The glycoprotein was a single component, as judged by gel filtration and analytical ultracentrifugation. The distribution of sedimentation coefficients was polydisperse but unimodal with an s025,w of 14.5S and a molecular weight of 1.72 X 10(6). The chemical composition of the glycoprotein was 77% carbohydrate and 21% protein, 52% of which was serine, threonine and proline. The glycoprotein had a strong negative charge and contained 3.1% and 18.3% by weight ester sulphate and sialic acid respectively. The molar proportion of N-acetylgalactosamine was nearly twice that of any of the other sugars present, the glycoprotein had A and H blood-group activity and the average maximum length of the carbohydrate chains was deduced to be six to eight sugar residues.


Author(s):  
M Karunakaran ◽  
Vivek C Gajare ◽  
Ajoy Mandal ◽  
Mohan Mondal ◽  
S K Das ◽  
...  

This experiment was conducted to study the electrophoretic characters of heparin binding proteins (HBP) of Black Bengal buck semen and their correlation with sperm characters and cryo-survivability. Semen ejaculates (n=20/buck) were collected from nine bucks and in vitro sperm characters were evaluated at collection, after equilibration and after freeze - thawing. HBP were isolated through heparin column and discontinuous Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) was performed to assess molecular weight. Significant difference (plessthan0.01) were observed among the bucks in sperm characters and freezability. Eight protein bands of 17 to 180 kDa in seminal plasma and 7 bands in sperm were found. 180 -136 kDa HBP of seminal plasma and 134-101 kDa HBP of sperm had showed high correlation with in vitro sperm characters. Further studies on identification of these proteins and their correlation with in vivo pregnancy are needed to find their role as marker for buck selection.


2000 ◽  
Vol 78 (3) ◽  
pp. 328-335 ◽  
Author(s):  
Christine Masterson ◽  
Clifford Wood

Carnitine palmitoyltransferase (EC 2.3.1.21), an enzyme that catalyses the reversible transfer of activated long-chain acyl groups between CoASH and L-carnitine, has been confirmed in pea leaf chloroplasts. This enzyme is bound to the chloroplast inner envelope membrane and has two isoforms, one bound to the outside (cytosol side) of the inner envelope and one bound to the inside (stromal side) of the inner envelope. Malonyl CoA inhibited the activity of the outer carnitine palmitoyltransferase, while stimulating the activity of the inner isoform and may be a regulator of these enzymes in vivo. Carnitine palmitoyltransferase was solubilized from the chloroplast envelope by detergent treatment and the two isoforms separated by Q-Sepharose anion exchange chromatography. Both proteins were immunochemically observed by probing Western blots of sodium dodecyl sulfate - polyacrylamide gel electrophoresis gels using an anti-beef heart mitochondrial carnitine palmitoyltransferase polyclonal antibody. The monomeric molecular mass of the protein recognized by this antibody was approximately 20 kDa. This 20-kDa protein also bound3H-carnitine. Both isoforms had broad acyl CoA substrate specificities, but showed increased activity with desaturated long-chain acyl CoAs, exhibiting a preference for linolenoyl CoA. A role for carnitine palmitoyltransferase in the shuttling of fatty acids across the chloroplast envelope is suggested.Key words: Pisum sativum, chloroplasts, carnitine palmitoyltransferase, fatty acid metabolism, eukaryotic pathway, membrane transport.


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