Enzymatic deglycosylation of porcine thyroid peroxidase: effects on catalytic activity and immunoreactivity

1991 ◽  
Vol 124 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Egberto G. Moura ◽  
Carmen C. Pazos-Moura ◽  
Naokata Yokoyama ◽  
Martha L. Dorris ◽  
Alvin Taurog
Keyword(s):  
Catalytic Activity ◽  
Molecular Mass ◽  
Antigenic Determinants ◽  
Enzyme Linked Immunosorbent Assay ◽  
Minor Role ◽  
Relative Molecular Mass ◽  
Thyroid Peroxidase ◽  
Autoimmune Thyroid ◽  
Tryptic Fragment ◽  
A Minor

Abstract Thyroid peroxidase is a heme-containing, membrane-bound, glycoprotein enzyme that catalyzes iodination and coupling in the thyroid gland. It is also the antigen for microsomal autoantibodies that are commonly found in the serum of patients with autoimmune thyroid disease. We examined the effect of deglycosylation on the catalytic functions and the immunoreactivity of this enzyme. A highly purified, solubilized, large tryptic fragment of porcine thyroid peroxidase, retaining all of the N-linked glycosylation sites of the native enzyme and displaying full catalytic activity was used. It was deglycosylated by treatment with N-glycanase under nondenaturing conditions. The loss in relative molecular mass after treatment, determined by gel electrophoresis, was about 75% of the estimated molecular weight of the glycan portion of porcine thyroid peroxidase. Lectin blots performed with horseradish peroxidase-conjugated concanavalin A showed a similar loss in relative molecular mass but some residual carbohydrate. The intensity of the carbohydrate stain was consistent with the loss of about 75% of the glycans. Despite this loss, three different assays for catalytic activity of porcine thyroid peroxidase were not significantly decreased. Immunoreactivity measured by immunoblotting and by enzyme-linked immunosorbent assay was also unimpaired. These findings suggest that N-glycanase-sensitive glycans in porcine thyroid peroxidase do not act as antigenic determinants and play a minor role, if any, in catalytic activity and, presumably therefore, in the maintenance of protein conformation.

scholarly journals Vitamin D and Autoimmune Thyroid Disease—Cause, Consequence, or a Vicious Cycle?

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2791
Author(s):  
Inês Henriques Vieira ◽  
Dírcea Rodrigues ◽  
Isabel Paiva
Keyword(s):  
Vitamin D ◽  
Thyroid Disease ◽  
Autoimmune Thyroid Disease ◽  
Minor Role ◽  
Vicious Cycle ◽  
Autoimmune Process ◽  
Autoimmune Thyroid ◽  
A Minor ◽  
Pleiotropic Expression ◽  
The Relationship

Vitamin D is a steroid hormone traditionally connected to phosphocalcium metabolism. The discovery of pleiotropic expression of its receptor and of the enzymes involved in its metabolism has led to the exploration of the other roles of this vitamin. The influence of vitamin D on autoimmune disease—namely, on autoimmune thyroid disease—has been widely studied. Most of the existing data support a relationship between vitamin D deficiency and a greater tendency for development and/or higher titers of antibodies linked to Hashimoto’s thyroiditis, Graves’ disease, and/or postpartum thyroiditis. However, there have also been some reports contradicting such relationships, thus making it difficult to establish a unanimous conclusion. Even if the existence of an association between vitamin D and autoimmune thyroid disease is assumed, it is still unclear whether it reflects a pathological mechanism, a causal relationship, or a consequence of the autoimmune process. The relationship between vitamin D’s polymorphisms and this group of diseases has also been the subject of study, often with divergent results. This text presents a review of the recent literature on the relationship between vitamin D and autoimmune thyroid disease, providing an analysis of the likely involved mechanisms. Our thesis is that, due to its immunoregulatory role, vitamin D plays a minor role in conjunction with myriad other factors. In some cases, a vicious cycle is generated, thus contributing to the deficiency and aggravating the autoimmune process.

Genetic Risk Factors for Autoimmune Thyroid Disease might Affect the Susceptibility to and Modulate the Progression of Primary Biliary Cholangitis

2017 ◽  
Vol 26 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Aleksander Kuś ◽  
Magdalena Arłukowicz Grabowska ◽  
Konrad Szymański ◽  
Ewa Wunsch ◽  
Małgorzata Milkiewicz ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Thyroid Disease ◽  
Autoimmune Thyroid Disease ◽  
Clinical Course ◽  
Assay Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Primary Biliary Cholangitis ◽  
Thyroid Peroxidase ◽  
Genome Wide Association Studies ◽  
Autoimmune Thyroid

Background & Aims: Patients with primary biliary cholangitis (PBC) frequently suffer from extrahepatic autoimmune conditions, of which autoimmune thyroid disease (AITD) is one of the most common. Previous studies identified several genetic variants increasing the odds of developing AITD. Here we investigate whether AITD-associated polymorphisms might also play a role in the development and clinical course of PBC and PBC associated with AITD (PBC-AITD).Methods: To this end, we prospectively recruited 230 patients with PBC and 421 healthy controls. Among recruited patients, 64 (30.9%) had PBC-AITD as diagnosed by elevated serum TPO-antibodies. In all subjects we genotyped 10 variants previously associated with AITD.Results: We detected significant associations between the PTPN22 polymorphism and risk of developing PBC (rs2476601, OR=1.43, P=0.035) as well as PBC-AITD (OR=1.74, P=0.028). The IL2RA polymorphism was associated with liver cirrhosis (rs41295061, OR=1.76, P=0.033) whereas the MMEL1 polymorphism increased the risk of requiring liver transplantation (rs2843403, OR=1.70, P=0.023). Although no significant differences in clinical or biochemical characteristics between patients with PBC and PBC-AITD were seen (all P>0.05), liver function tests and metabolic traits in PBC patients were significantly (all P<0.05) affected by the CTLA4 (rs3087243), MMEL1 (rs2843403), PTPN22 (rs2476601) and RNASET2 (rs9355610) variants.Conclusion: Our study demonstrates the existence of a genetic overlap between PBC and AITD. Apparently, genetic variants known to increase the AITD risk might affect the clinical course of PBC. On the other hand, AITD per se does not seem to significantly influence the natural history of PBC.Abbreviations: AITD: autoimmune thyroid disease; ALP: alkaline phosphatase; ALT: alanine transaminase; AMA: anti-mitochondrial autoantibodies; AST: aspartate aminotransferase; DM1: diabetes mellitus type 1; ELISA: enzyme-linked immunosorbent assay method; GGT: gamma-glutamyl transpeptidase; GD: Graves’ disease; GWAS: genome-wide association studies; HT: Hashimoto thyroiditis; HWE: Hardy-Weinberg equilibrium; Lyp: lymphoid-specific protein tyrosine phosphatase non-receptor type 22; OR: odds ratio; PBC: primary biliary cholangitis; RA: rheumatoid arthritis; SLE: systemic lupus erythematosus; TPOAb: thyroid peroxidase antibody; UDCA: ursodeoxycholic acid.

Cross-reaction of eye muscle antibodies with thyroid tissue in thyroid-associated ophthalmopathy

1989 ◽  
Vol 122 (1) ◽  
pp. 201-NP ◽  
Author(s):  
D. Weightman ◽  
P. Kendall-Taylor
Keyword(s):  
Thyroid Disease ◽  
Autoimmune Thyroid Disease ◽  
Thyroid Tissue ◽  
Cross Reaction ◽  
Antigenic Determinants ◽  
Enzyme Linked Immunosorbent Assay ◽  
Western Blots ◽  
Eye Muscle ◽  
Autoimmune Thyroid ◽  
Thyroid Associated Ophthalmopathy

ABSTRACT The nature of the association of ophthalmopathy with autoimmune thyroid disease is not understood. Serum autoantibodies to eye muscle have previously been identified and in this study we have explored the hypothesis that there may be shared antigenic determinants between orbital and thyroid tissues. Sera were obtained from patients in whom eye muscle antibodies (EMAb) had been detected by an enzyme-linked immunosorbent assay (ELISA); the sera were preincubated with membrane preparations of thyroid or eye muscle, hepatic membranes being used as control. Tissue-binding antibodies were removed from serum by centrifugation and the supernatant serum was analysed using an indirect ELISA and by immunoblotting. In the ELISA, all sera gave a positive response for EMAb. In one serum, the binding was entirely non-specific. All sera showed significant neutralization of EMAb by eye muscle. In six sera there was reduction of EMAb after exposure to thyroidal antigens, indicative of cross-reaction. Western blotting confirmed the non-specific nature of the binding in one serum. In five of the remaining nine sera, protein bands were identified which interacted specifically with eye muscle and, in two of these, the same determinants were neutralized by preincubation with thyroid tissue. The Western blots confirmed the findings in the ELISA. The determinants recognized by IgG were variable between patients and no common antigen could be identified. This study demonstrates that, in some cases of thyroid-associated ophthalmopathy, there is cross-reaction of EMAb with thyroidal antigens, but this is variable and not found in every case. This may explain the association of the disease with autoimmune thyroid disease, at least in some cases. Journal of Endocrinology (1989) 122, 201–206

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Produktivkraft als Versprechen

2016 ◽  
Vol 46 (185) ◽  
pp. 621-638 ◽  
Author(s):  
Christian Siefkes
Keyword(s):  
Private Consumption ◽  
Minor Role ◽  
Progressive Reduction ◽  
Internal Forces ◽  
A Minor

The ‘Fragment on Machines’ from Marx’s Grundrisse is often cited as an argument that the internal forces of capitalism will lead to its doom. But the argument that the progressive reduction of labor must doom capitalism lacks a proper foundation, as a comparison with the ‘Schemes of Reproduction’ given in Capital II shows. The latter, however, aren’t fully convincing either. In reality, more depends on the private consumption of capitalists than either model recognizes. Ultimately, most can be made of the ‘Fragment on Machines’ by reading it not as an exposure of capitalism’s internal contractions, but as a discussion of a possible communist future where labor (or work) will play but a minor role.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

Extraction of polyethylene glycols with dicarbolide solutions in nitrobenzene

1990 ◽  
Vol 55 (8) ◽  
pp. 1959-1967 ◽  
Author(s):  
Petr Vaňura ◽  
Pavel Selucký
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Mass ◽  
Extraction Constant ◽  
Metal Extraction ◽  
Polyethylene Glycols ◽  
Relative Molecular Mass ◽  
Published Data ◽  
Average Molecular Mass ◽  
Peg 400 ◽  
Extraction Constants

The extraction of polyethylene glycol of average molecular mass 400 (PEG 400) with dicarbolide solution in nitrobenzene and of longer-chain polyethylene glycol, of average molecular mass 1 500 (PEG 1 500), with chlorinated dicarbolide solution in nitrobenzene was studied. During the extraction of PEG 400, the polyethylene glycol solvates the Horg+ ion in the organic phase giving rise to the HLorg+ species (L is polyethylene glycol). The obtained value of the extraction constant Kex(HLorg+) = 933 is consistent with published data of metal extraction. Extraction of PEG 1 500 was treated applying the simplified assumption that the thermodynamic behaviour of PEG 1 500 is the same as that of n molecules of polyethylene glycol with relative molecular mass 1 500/n, each solvating one cation. For this model, the value of n = 3.2 ± 1.1 and the values of the extraction constants of the HL1/n,org+ and HL2/n,org+ species were obtained by using the adapted program LETAGROP. This value of n is consistent with published extraction data in the presence of polyethylene glycol with a relative molecular mass from 200 to 1 000.

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