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1.
Clin Chim Acta ; 548: 117489, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37451420

RESUMO

BACKGROUND: Endometriosis is an immune-mediated inflammatory disease that causes the growth of endometrial-like tissue outside the uterus. Diagnostics of this disease are difficult, often invasive, and time-consuming, therefore non-invasive diagnostic methods and parameters are very desirable in endometriosis detection. OBJECTIVES: The study aimed to check whether there are any differences in the monosaccharide composition of N-glycans in serum IgG of women with advanced endometriosis and women with mild gynecological diseases. MATERIALS AND METHODS: The study material consisted of IgG samples isolated from blood sera derived from patients diagnosed with advanced endometriosis and women without endometriosis but with other gynecological diseases. To determine the monosaccharide composition of N-glycans in IgG, the gas chromatography-mass spectrometry (GC-MS) method was used. RESULTS: It was observed a significantly higher content of GlcNAc in the group of women with mild gynecological diseases, compared to the group of patients with advanced endometriosis (6.5 ± 5.2 and 4.5 ± 5.7; p = 0.0007704, respectively). In addition, the content of fucose was significantly higher in the group of women with mild gynecological diseases compared to women with advanced endometriosis (1.9 ± 0.5 and 1.7 ± 1.2; p = 0.000274, respectively). CONCLUSIONS: The content of GlcNAc and fucose in serum IgG may be useful markers differentiating patients with advanced endometriosis from women without endometriosis but with mild gynecological diseases.


Assuntos
Endometriose , Humanos , Feminino , Endometriose/diagnóstico , Cromatografia Gasosa-Espectrometria de Massas , Fucose , Polissacarídeos , Imunoglobulina G , Monossacarídeos
2.
Int J Mol Sci ; 23(15)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35897676

RESUMO

Endometriosis is a gynecological disease, the pathogenesis of which seems to be directly related to inflammatory processes with an immune basis. Our study aimed to analyze the O-glycosylation of native serum IgG and IgG isolated from sera of women with advanced endometriosis, without endometriosis but with benign gynecological diseases, and from a control group of healthy women, in the context of its utility for differentiation of advanced endometriosis from the other two groups of women studied. For the analysis of serum IgG O-glycosylation and the expression of multi-antennary N-glycans, lectin-ELISA with lectins specific to O-glycans (MPL, VVL, and Jacalin) and highly branched N-glycans (PHA-L) was used. The relative reactivities of isolated serum IgG O-linked glycans with specific lectins as well as the MPL/VVL O-glycosylation ratio were significantly higher in patients with advanced endometriosis and those with other gynecological diseases when compared to the control group of healthy women. We also showed significantly higher expression of PHA-L-reactive multi-antennary N-glycans in isolated IgG in the advanced endometriosis and the non-endometriosis groups in comparison to the control group. Additionally, significantly higher expression of Jacalin-reactive O-glycans in isolated IgG was observed in the non-endometriosis than in the advanced endometriosis group. The results of the ROC curve and cluster analysis additionally confirmed that the lectin-based analysis of isolated serum IgG O-glycosylation and the expression of highly branched N-glycans may help distinguish women with advanced endometriosis from healthy women. Moreover, the analysis of the expression of Jacalin-reactive i-IgG O-glycans may be helpful in differentiation between women with advanced endometriosis and patients with other gynecological diseases with an inflammatory background. In the case of non-endometriosis patients, the observed differences were most probably caused by increased expression of core 3 type O-glycans.


Assuntos
Imunoglobulina G , Lectinas , Feminino , Glicosilação , Humanos , Inflamação , Lectinas/metabolismo , Polissacarídeos/metabolismo
3.
J Inflamm Res ; 15: 251-266, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35058701

RESUMO

BACKGROUND: Endometriosis is an inflammatory disease leading to the growth of endometrial-like tissue outside of the uterus, which affects approximately 10% of young women of reproductive potential. The diagnosis of this disease is difficult, often invasive and time-consuming, therefore non-invasive diagnostic methods are strongly desirable in endometriosis detection. The aim of our project was to investigate whether any associations exist between the expression of serum IgG fucosylation and advanced stages of endometriosis. We were also interested in whether native serum IgG (s-IgG) fucosylation analysis, without prior IgG isolation, could provide a panel of parameters helpful in non-invasive diagnostics of advanced endometriosis. METHODS: IgG fucosylation was examined using a lectin-ELISA test with fucose-specific lectins: AAL and LCA, specific for core fucose α1,6-linked, as well as LTA and UEA which recognize α1,3- and α1,2-linked fucose, respectively. RESULTS: ROC curve and cluster analysis showed s-IgG reactivities with the panel of fucose-specific lectins AAL, LCA and LTA. CONCLUSION: s-IgG reactivity with the panel of fucose-specific lectins AAL, LCA and LTA can be taken into account as a useful diagnostic and clinical tool to differentiate women with advanced endometriosis. Moreover, it has been shown that the analysis of native IgG fucosylation directly in serum, without prior time-consuming, expensive IgG isolation, is sufficient to distinguish advanced stages of endometriosis from a control group of healthy women.

5.
Sci Rep ; 11(1): 5586, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33692455

RESUMO

Endometriosis is an inflammatory disease which diagnostics is difficult and often invasive, therefore non-invasive diagnostics methods and parameters are needed for endometriosis detection. The aim of our study was to analyse the glycosylation of native serum IgG and IgG isolated from sera of women classified as: with endometriosis, without endometriosis but with some benign ginecological disease, and control group of healthy women, in context of its utility for differentiation of advanced endometriosis from the group of healthy women. IgG sialylation and galactosylation/agalactosylation degree was determined using specific lectins: MAA and SNA detecting sialic acid α2,3- and α2,6-linked, respectively, RCA-I and GSL-II specific to terminal Gal and terminal GlcNAc, respectively. The results of ROC and cluster analysis showed that the serum IgG MAA-reactivity, sialylation and agalactosylation factor may be used as supplementary parameters for endometriosis diagnostics and could be taken into account as a useful clinical tool to elucidate women with high risk of endometriosis development. Additionally, we have shown that the analysis of native serum IgG glycosylation, without the prior time-consuming and expensive isolation of the protein, is sufficient to differentiation endometriosis from a group of healthy women.


Assuntos
Endometriose/sangue , Imunoglobulina G/sangue , Ácido N-Acetilneuramínico/sangue , Adulto , Feminino , Glicosilação , Humanos
7.
Arch Immunol Ther Exp (Warsz) ; 66(6): 407-413, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30327837

RESUMO

Archivum Immunologiae et Therapiae Experimentalis (AITE) was founded in 1953 by Ludwik Hirszfeld, a world famous Polish physician and scientist in the field of microbiology and immunology. Initially, AITE was published in Polish, but within a few years, it changed to English to increase the range and number of international readers. In its over 65 year history, AITE has had several Editors and a number of Publishers. In the period 1977-1991, AITE was listed in the system of scientific information Current Contents/Life Sciences, but for several years, its impact on the international readership of the Journal was negligible. The political and economic crisis in Poland in late 1980s led to serious delays in printing of successive AITE issues, so the Journal was removed from the Current Contents. Year 1991 was a turning point for the Journal, guided since then by prof. Dubowska-Inglot, who changed its image and format, and allowed acceptance of review articles. In 1999, prof. Górski became the Editor-in-Chief, giving a new impulse for further development of the Journal. In a consequence, AITE was accepted to Science Citation Index Expanded (in 2001) and to Institute for Scientific Information Master Journal List (in 2002). Eventually, AITE has evolved to become a truly international, multidisciplinary journal, publishing original articles, and reviews relating to basic and clinical immunology, experimental therapy, immunogenetics, transplantology, microbiology, immunochemistry, as well as bioethics. Currently, AITE is cited in a number of major scientific information databases. Since 2011, the Journal is published by Springer Publishing House, it has achieved international recognition with its latest impact factor (for 2017) of 3.018. AITE, whose Editors are professors of Hirszfeld Institute of Immunology and Experimental Therapy, strengthens the status and position of the Institute as one of the leading scientific institutions in Poland.


Assuntos
Alergia e Imunologia , Imunoterapia/tendências , Editoração , Humanos , Cooperação Internacional , Fator de Impacto de Revistas , Polônia
8.
Arch Immunol Ther Exp (Warsz) ; 64(2): 149-56, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26439848

RESUMO

The erythrocyte binding ligand 140 (EBA-140) is a member of the Plasmodium falciparum erythrocyte binding antigens (EBA) family, which are considered as prospective candidates for malaria vaccine development. EBA proteins were identified as important targets for naturally acquired inhibitory antibodies. Natural antibody response against EBA-140 ligand was found in individuals living in malaria-endemic areas. The EBA-140 ligand is a paralogue of the well-characterized P. falciparum EBA-175 protein. They both share homology of domain structure, including the binding region (Region II), which consists of two homologous F1 and F2 domains and is responsible for ligand-erythrocyte receptor interaction during merozoite invasion. It was shown that the erythrocyte receptor for EBA-140 ligand is glycophorin C-a minor human erythrocyte sialoglycoprotein. In studies on the immunogenicity of P. falciparum EBA ligands, the recombinant proteins are of great importance. In this report, we have demonstrated that the recombinant baculovirus-obtained EBA-140 Region II is immunogenic and antigenic. It can raise specific antibodies in rabbits, and it is recognized by natural antibodies present in sera of patients with malaria, and thus, it may be considered for inclusion in multicomponent blood-stage vaccines.


Assuntos
Proteínas de Transporte/metabolismo , Eritrócitos/fisiologia , Vacinas Antimaláricas/imunologia , Malária Falciparum/prevenção & controle , Plasmodium falciparum/imunologia , Proteínas de Protozoários/metabolismo , Animais , Formação de Anticorpos , Baculoviridae/genética , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Vetores Genéticos/genética , Humanos , Malária Falciparum/imunologia , Proteínas de Membrana , Ligação Proteica , Domínios Proteicos/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Coelhos , Células Sf9 , Vacinas Sintéticas/imunologia
10.
FEBS Lett ; 588(23): 4319-24, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25304424

RESUMO

We previously showed that lumican regulates MMP-14 expression. The aim of this study was to compare the effect of lumican and decorin on MMP-14 activity. In contrast to decorin, the glycosylated form of lumican was able to significantly decrease MMP-14 activity in B16F1 melanoma cells. Our results suggest that a direct interaction occurs between lumican and MMP-14. Lumican behaves as a competitive inhibitor which leads to a complete blocking of the activity of MMP-14. It binds to the catalytic domain of MMP-14 with moderate affinity (KD∼275 nM). Lumican may protect collagen against MMP-14 proteolysis, thus influencing cell-matrix interaction in tumor progression.


Assuntos
Proteoglicanas de Sulfatos de Condroitina/farmacologia , Sulfato de Queratano/farmacologia , Metaloproteinase 14 da Matriz/metabolismo , Inibidores de Metaloproteinases de Matriz/farmacologia , Animais , Ligação Competitiva , Linhagem Celular Tumoral , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Colágeno/metabolismo , Humanos , Sulfato de Queratano/metabolismo , Lumicana , Inibidores de Metaloproteinases de Matriz/metabolismo , Camundongos , Proteólise/efeitos dos fármacos
11.
Transfus Med Rev ; 28(3): 126-36, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24895151

RESUMO

Antigens belonging to the P1PK, GLOB, and FORS blood group systems and the GLOB blood group collection represent a closely related set of 13 glycosphingolipids (GSLs). They are synthesized by the coordinated action of glycosyltransferases, encoded by at least 7 different loci. Three of these enzymes show either different activity or a different mRNA expression profile due to genetic polymorphisms, resulting in blood group diversity. In recent years, significant progress has been made in understanding the molecular background and biological functions of these GSLs. Their medical significance is often related to the existence of natural antibodies, as they may cause complications after transfusions and during pregnancies. In addition, GSLs belonging to these blood group systems are receptors for several pathogens. This review summarizes the present knowledge about the complicated network of enzymatic interactions leading to synthesis of these GSLs, as well as their clinical implications.


Assuntos
Antígenos de Grupos Sanguíneos/química , Glicoesfingolipídeos/química , Sistema do Grupo Sanguíneo P/imunologia , Transfusão de Sangue , Feminino , Genótipo , Globosídeos/química , Glicoesfingolipídeos/genética , Humanos , Masculino , Fenótipo , Polimorfismo Genético , Gravidez , Receptores Imunológicos , Receptores Virais
12.
Przegl Lek ; 70(3): 131-4, 2013.
Artigo em Polonês | MEDLINE | ID: mdl-24003667

RESUMO

Over last few years, biosensors have become increasingly used as a research tool. Using innovative techniques of detection and estimation of the strength of intermolecular bonds, is particularly important in biochemical processes, including the study of mechanisms of interactions between plasma proteins in the circulatory system. With the numerous enhancements biosensors have become extremely sensitive devices, allowing for analysis of diverse biological material. Moreover, the use of immobilization techniques enables to use sample repeatedly, which significantly reduces costs and the ability to monitor tests in real-time shorten the time of experiment. The presented work discusses examples of the usage of biosensors in the research on the mechanisms of the interactions of blood plasma proteins. The experiments on cancer biomarkers present in the blood circulation system, protein C deficiency causing non-controlled hemorrhagic accidents, and on the level of fibrinogen, as well as 20S proteasome concentration in plasma, are just some examples of biosensors usage in the analyses of blood. They are also applicable in the research work performed the project WROVASC--Integrated Cardiovascular Center, concerning the mechanisms of anticoagulant activity in blood plasma of the polyphenolic-polysaccharide macromolecules of plant origin.


Assuntos
Biomarcadores Tumorais/sangue , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Proteínas Sanguíneas/análise , Anticoagulantes/sangue , Biomarcadores/sangue , Técnicas Biossensoriais/economia , Controle de Custos , Hemorragia/sangue , Humanos
13.
Anim Sci J ; 84(10): 702-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23607457

RESUMO

Glycated proteins are considered as one of the factors involved in the pathogenesis of diabetic complications, including nephropathy. These proteins are formed endogenously under conditions of hyperglycemia, as well as being provided with food containing sugars, which was subjected to high temperature. Examples are egg products. One of the proteins found in eggs in a relatively high concentration is chicken cystatin (ovocystatin). It is now believed that some proteins can passage the intestinal epithelium by transcytosis directly into the bloodstream. Thus, glycated protein present in food can be an additional source of glycotoxins. The aim of this study was to compare the affinity of native and glycated cystatin to the brush border membranes of rat kidney. Kinetic analysis was performed with surface plasmon resonance technique using sensor chip L1. Dissociation constants for native and glycated cystatin (Kd ) were 2.76 µmol/L and 3.82 µmol/L, respectively. The results of our study indicate that glycation only slightly affects binding of cystatin to brush border membranes. This suggests that glycated cystatin and other glycated proteins may also be efficiently taken up in the kidney proximal tubule. The observation may be important for understanding the mechanisms involved in the development of diabetic nephropathy.


Assuntos
Rim/metabolismo , Animais , Galinhas , Cistatinas/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Microvilosidades/metabolismo , Peptídeos/metabolismo , Ratos
14.
Neurochem Res ; 37(6): 1154-69, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22451227

RESUMO

Spingolipids (SLs) are an important component of central nervous system (CNS) myelin sheaths and affect the viability of brain cells (oligodendrocytes, neurons and astrocytes) that is determined by signaling mediated by bioactive sphingoids (lyso-SLs). Recent studies indicate that two lipids, ceramide and sphingosine 1-phosphate (S1P), are particularly involved in many human diseases including the autoimmune inflammatory demyelination of multiple sclerosis (MS). In this review we: (1) Discuss possible sources of ceramide in CNS; (2) Summarize the features of the metabolism of S1P and its downstream signaling through G-protein-coupled receptors; (3) Link perturbations in bioactive SLs metabolism to MS neurodegeneration and (4) Compile ceramide and S1P relationships to this process. In addition, we described recent preclinical and clinical trials of therapies targeting S1P signaling, including 2-amino-2-propane-1,3-diol hydrochloride (FTY720, fingolimod) as well as proposed intervention to specify critical SL levels that tilt balances of apoptotic/active ceramide versus anti-apoptotic/inactive dihydroceramide that may offer a novel and important therapeutic approach to MS.


Assuntos
Ceramidas/metabolismo , Lisofosfolipídeos/fisiologia , Esclerose Múltipla/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Esfingolipídeos/fisiologia , Esfingolipídeos/uso terapêutico , Esfingosina/análogos & derivados , Apoptose , Ceramidas/antagonistas & inibidores , Ácidos Graxos Monoinsaturados/uso terapêutico , Cloridrato de Fingolimode , Humanos , Redes e Vias Metabólicas , Esclerose Múltipla/fisiopatologia , Bainha de Mielina/patologia , Propilenoglicóis/uso terapêutico , Receptores Acoplados a Proteínas G/metabolismo , Serina C-Palmitoiltransferase/antagonistas & inibidores , Esfingosina/fisiologia , Esfingosina/uso terapêutico
15.
Arch Biochem Biophys ; 498(2): 127-35, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20434428

RESUMO

We previously showed that a small proportion of the O-linked oligosaccharide chains of human glycophorin A (GPA) contains blood group A, B or H antigens, relevant to the ABO phenotype of the donor. The structures of these minor O-glycans have been established (Podbielska et al. (2004) [20]). By the use of immunochemical methods we obtained results indicating that ABH blood group epitopes are also present in N-glycan of human GPA (Podbielska and Krotkiewski (2000) [22]). In the present paper we report a detailed analysis of GPA N-glycans using nanoflow electrospray ionization tandem mass spectrometry. N-glycans containing A-, B- and H-related sequences were identified in GPA preparations obtained from erythrocytes of blood group A, B and O donors, respectively. The ABH blood group epitopes are present on one antenna of the N-glycan, whereas a known sialylated sequence NeuAcalpha2-6Galbeta1-4GlcNAc- occurs on the other antenna and other details are in agreement with the known major structure of the GPA N-glycan. In the bulk of the biantennary sialylated N-glycans released from GPA preparations, the blood group ABH epitopes-containing N-glycans, similarly O-glycans, constituted only a minor part. The amount relative to other N-glycans was estimated to 2-6% of blood group H epitope-containing glycans released from GPA-O preparations and 1-2% of blood group A and B epitope-containing glycans, released from GPA-A and GPA-B, respectively.


Assuntos
Sistema ABO de Grupos Sanguíneos/química , Epitopos/química , Glicoforinas/química , Oligossacarídeos/química , Humanos , Espectrometria de Massas/métodos
16.
Biochim Biophys Acta ; 1770(5): 774-80, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17343985

RESUMO

Protein O-mannosylation has been postulated to be critical for production and secretion of glycoproteins in fungi. Therefore, understanding the regulation of this process and the influence of heterologous expression of glycoproteins on the activity of enzymes engaged in O-glycosylation are of considerable interest. In this study we expressed cellobiohydrolase II (CBHII) of T. reesei, which is normally highly O-mannosylated, in Saccharomyces cerevisiae pmt mutants partially blocked in O-mannosylation. We found that the lack of Pmt1 or Pmt2 protein O-mannosyltransferase activity limited the glycosylation of CBHII, but it did not affect its secretion. The S. cerevisiae pmt1Delta and pmt2Delta mutants expressing T. reesei cbh2 gene showed a decrease of GDP-mannose level and a very high activity of cis-prenyltransferase compared to untransformed strains. On the other hand, elevation of cis-prenyltransferase activity by overexpression of the S. cerevisiae RER2 gene in these mutants led to an increase of dolichyl phosphate mannose synthase activity, but it did not influence the activity of O-mannosyltransferases. Overexpression of the MPG1 gene increased the level of GDP-mannose and stimulated the activity of mannosyltransferases elongating O-linked sugar chains, leading to partial restoration of CBHII glycosylation.


Assuntos
Celulose 1,4-beta-Celobiosidase/metabolismo , Guanosina Difosfato Manose/metabolismo , Manosiltransferases/genética , Saccharomyces cerevisiae/genética , Transferases/metabolismo , Trichoderma/genética , Celulose 1,4-beta-Celobiosidase/genética , Glicosilação , Guanosina Difosfato Manose/genética , Manosiltransferases/metabolismo , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Transferases/genética , Trichoderma/enzimologia
17.
Glycobiology ; 17(3): 304-12, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17118951

RESUMO

Rare polyagglutinable erythrocytes of NOR phenotype were found to contain two unique glycosphingolipids (designated NOR1 and NOR2). These components (not detected in normal erythrocytes) were reactive with Griffonia simplicifolia isolectin IB4 (GSL-IB4) and commonly present human anti-NOR antibodies. The NOR1 component has been reported to be a globoside containing a single galactose residue linked alpha1,4 to the terminal N-acetylgalactosamine. Here, we report the structural studies on a second glycolipid, NOR2, and a third novel component migrating in high-performance thin-layer chromatography (HPTLC) between NOR1 and NOR2. The structures were determined by a combination of ion trap sequential mass spectrometry (MALDI-QIT-TOF) and step-wise treatment with glycosidases, followed by identification of products on HPTLC plates with lectins and mouse monoclonal anti-NOR antibody. The NOR2 component was found to be a disaccharide extension of NOR1 with the following structure: Galalpha1-4GalNAcbeta1-3Galalpha1-4GalNAcbeta1-3Galalpha1-4Galbeta1-4Glcbeta1-Cer. Treatment of NOR2 with alpha-galactosidase gave a glycolipid migrating between NOR1 and NOR2, which did not react with either GSL-IB4 or anti-NOR antibodies but did react with GalNAc-specific soybean agglutinin. This intermediate glycolipid (now designated NOR(int)) was identified as a relatively abundant component of a neutral glycolipid fraction from NOR erythrocytes, suggesting its presence as a precursor to NOR2. The structure of NOR(int) was also confirmed by sequential mass spectrometry studies. These results indicate that polyagglutination in NOR subjects is due to unique erythrocyte glycolipids that are synthesized by sequential addition of Galalpha1,4 and GalNAcbeta1,3 to globoside.


Assuntos
Eritrócitos/imunologia , Globosídeos/química , Hemaglutinação , Sequência de Carboidratos , Cromatografia Líquida de Alta Pressão , Globosídeos/imunologia , Humanos , Dados de Sequência Molecular , Estrutura Molecular , Ácido Periódico/química , Fenótipo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
18.
Glycoconj J ; 23(7-8): 463-71, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17006638

RESUMO

It is well documented that serum IgG from rheumatoid arthritis (RA) patients exhibits decreased galactosylation of its conservative N-glycans (Asn-297) in CH2 domains of the heavy chains; it has been shown that this agalactosylation is proportional to disease severity. In the present investigation we analyzed galactosylation of IgG derived from the patients using a modified ELISA-plate test, biosensor BIAcore and total sugar analysis (GC-MS). For ELISA and BIAcore the binding of IgG preparations, purified from the patients' sera, to two lectins: Ricinus communis (RCA-I) and Griffonia simplicifolia (GSL-II) was applied. Based on ELISA-plate test an agalactosylation factor (AF, a relative ratio of GSL-II/RCA-I binding) was calculated, which was proportional to actual disease severity. Repeated testing of several patients before and after treatment with methotrexate (MTX) alone or in combination with Remicade (a chimeric antibody anti-TNF-alpha) supplied results indicating an increase of IgG galactosylation during the treatment. This introductory observation suggests that IgG galactosylation may be an additional indicator of the RA patients' improvement.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/imunologia , Imunoglobulina G/sangue , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Antirreumáticos/uso terapêutico , Ensaio de Imunoadsorção Enzimática/métodos , Galactose/química , Humanos , Imunoglobulina G/química , Infliximab , Lectinas , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Ressonância de Plasmônio de Superfície/métodos
19.
Biochemistry ; 43(47): 14948-57, 2004 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-15554702

RESUMO

Fructose 1,6-bisphosphatase (FBPase) is known to form a supramolecular complex with alpha-actinin and aldolase on both sides of the Z-line in skeletal muscle cells. It has been proposed that association of aldolase with FBPase not only desensitizes muscle FBPase toward AMP inhibition but it also might enable the channeling of intermediates between the enzymes [Rakus et al. (2003) FEBS Lett. 547, 11-14]. In the present paper, we tested the possibility of fructose 1,6-bisphosphate (F1,6-P(2)) channeling between aldolase and FBPase using the approach in which an inactive form of FBPase competed with active FBPase for binding to aldolase and thus decreased the rate of aldolase-FBPase reaction. The results showed that F1,6-P(2) is transferred directly from aldolase to FBPase without mixing with the bulk phase. Further evidence that F1,6-P(2) is channeled from aldolase to FBPase comes from the experiments investigating the inhibitory effect of a high concentration of magnesium ions on aldolase-FBPase activity. FBPase in a complex with aldolase, contrary to free muscle FBPase, was not inhibited by high Mg(2+) concentrations, which suggests that free F1,6-P(2) was not present in the assay mixture during the reaction. A real-time interaction analysis between aldolase and FBPase revealed a dual role of Mg(2+) in the regulation of the aldolase-FBPase complex stability. A physiological concentration of Mg(2+) increased the affinity of muscle FBPase to muscle aldolase, whereas higher concentrations of the cation decreased the concentration of the complex. We hypothesized that the presence of Mg(2+) stabilizes a positively charged cavity within FBPase and that it might enable an interaction with aldolase. Because magnesium decreased the binding constant (K(a)) between aldolase and FBPase in a manner similar to the decrease of K(a) caused by monovalent cations, it is postulated that electrostatic attraction might be a driving force for the complex formation. It is presumed that the biological relevance of F1,6-P(2) channeling between aldolase and FBPase is protection of this glyconeogenic, as well as glycolytic, intermediate against degradation by cytosolic aldolase, which is one of the most abundant enzyme of glycolysis.


Assuntos
Frutose-Bifosfatase/metabolismo , Frutose-Bifosfato Aldolase/metabolismo , Músculo Esquelético/química , Músculo Esquelético/enzimologia , Especificidade por Substrato , Actinina/metabolismo , Monofosfato de Adenosina/farmacologia , Animais , Cátions Monovalentes/farmacologia , Simulação por Computador , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Frutose-Bifosfatase/antagonistas & inibidores , Frutose-Bifosfatase/isolamento & purificação , Frutose-Bifosfato Aldolase/antagonistas & inibidores , Frutose-Bifosfato Aldolase/isolamento & purificação , Cinética , Magnésio/metabolismo , Magnésio/farmacologia , Modelos Moleculares , Polietilenoglicóis , Ligação Proteica , Desnaturação Proteica , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/farmacologia , Coelhos , Espectrometria de Fluorescência , Eletricidade Estática , Ressonância de Plasmônio de Superfície , Temperatura , o-Ftalaldeído/farmacologia
20.
Arch Biochem Biophys ; 429(2): 145-53, 2004 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-15313217

RESUMO

The major O-linked oligosaccharide structures attached to human glycophorin A (GPA) have been extensively characterized previously. Our own recent findings, obtained by immunochemical methods, suggested the presence of blood group A and B determinants in O-glycans of human glycophorin originating from blood group A or B erythrocytes, respectively. Here, we elucidate the structure of O-glycans, isolated from GPA of blood group A, B, and O individuals by reductive beta-elimination, carrying A, B or H blood group epitopes, respectively. Structural studies based on nanoflow electrospray-ionization tandem mass spectrometry and earlier reported data on the carbohydrate moiety of GPA and ABH antigens allowed us to conclude that these blood group epitopes are elongations of the beta-GlcNAc branch attached to C-6 of the reducing GalNAc. The galactose linked to C-3 of the reducing GalNAc carries NeuAcalpha2-3 linked residue. Identified here O-glycans were found in low amounts, their content estimated at about one percent of all GPA O-glycans. These O-glycans with type-2 core, carrying the blood group A, B or H determinants, have not been identified in GPA so far. Our results demonstrate the efficacy of nanoESI MS/MS in detecting minor oligosaccharide components present in a mixture with much more abundant structures.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Glicoforinas/imunologia , Polissacarídeos/química , Western Blotting , Sequência de Carboidratos , Eletroforese em Gel de Poliacrilamida , Metilação , Dados de Sequência Molecular , Polissacarídeos/imunologia , Espectrometria de Massas por Ionização por Electrospray
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