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1.
Clin Exp Immunol ; 197(3): 361-365, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31032886

RESUMO

The objectives of this study were to evaluate patients with aortic abdominal aneurysm (AAA) with regard to immunoglobulin (Ig)G4-related disease (IgG4-RD). IgG4-RD represents a recently defined condition comprised of a collection of disorders characterized by IgG4 hypergammaglobulinemia, the presence of IgG4-positive plasma cells in organs affected with fibrotic or sclerotizing changes and typical histopathological features. It was identified as a possible cause of vasculitis in large vessels. Studies have been published on a possible association between inflammatory aortic or cardiovascular disease and IgG4-RD. We examined 114 patients with AAA requiring surgery in order to identify findings which are characteristic of IgG4-RD. Aneurysm samples from seven patients showed histopathological features consistent with IgG4-RD and the presence of IgG4+ plasma cells. Only two of these seven patients showed elevated IgG4 serum levels higher 1·35 g/l. In five of the patients, the concentration of serum IgG4 was lower than 1·20 g/l, with the number of IgG4+ plasma cells being higher than 50/high-power field. These findings were consistent with AAA being a heterogeneous group of inflammatory diseases with different pathogenesis.


Assuntos
Aneurisma da Aorta Abdominal/imunologia , Hipergamaglobulinemia/imunologia , Doença Relacionada a Imunoglobulina G4/imunologia , Imunoglobulina G/imunologia , Plasmócitos/imunologia , Idoso , Aorta/imunologia , Aorta/metabolismo , Aorta/patologia , Aneurisma da Aorta Abdominal/sangue , Aneurisma da Aorta Abdominal/patologia , Feminino , Humanos , Hipergamaglobulinemia/sangue , Hipergamaglobulinemia/patologia , Imunoglobulina G/sangue , Doença Relacionada a Imunoglobulina G4/sangue , Doença Relacionada a Imunoglobulina G4/patologia , Masculino , Pessoa de Meia-Idade , Plasmócitos/metabolismo , Plasmócitos/patologia , Estudos Retrospectivos
2.
Physiol Res ; 68(3): 385-394, 2019 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-30904002

RESUMO

Abdominal aortic aneurysm (AAA) is a serious condition of unclear pathogenesis and progression. Two samples were collected from 48 patients during AAA surgery. One sample was collected from the aneurysm, the other from the aneurysm proximal neck where the tissue did not exhibit any aneurysmal changes. Subsequently, gene expression profiles using microarrays (Illumina) were compared in RNA extracted from the samples. Overall, 2,185 genes were found to be upregulated and 2,100 downregulated; from which 158 genes had a different expression with FDR<0.05 (False Discovery Rate) and FC>/=2 (Fold Change). Of this number, 115 genes were over-expressed and 43 under-expressed. The analysis of the gene list based on their biological pathways revealed that the regulation of inflammation was mediated by chemokine and cytokine signaling pathways, the integrin signaling pathway, and T and B cell activation. Moreover, a change was identified in the expression of genes involved in both intercellular and intracellular signaling systems.


Assuntos
Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/imunologia , Perfilação da Expressão Gênica/métodos , Mediadores da Inflamação/imunologia , Idoso , Aneurisma da Aorta Abdominal/metabolismo , Feminino , Expressão Gênica/fisiologia , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade
4.
Prague Med Rep ; 114(4): 246-57, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24485342

RESUMO

In this retrospective study we assessed the frequency of hypogammaglobulinemia in 708 patients with SIRS, severe sepsis and septic shock. We evaluated the relationship between hypogammaglobulinemia IgG, IgM and 28 day mortality. Total of 708 patients and 1,513 samples were analyzed. In the three subgroups we investigated, patients met the criteria of SIRS, severe sepsis and septic shock. IgG hypogammaglobulinemia was demonstrated in 114 patients with severe sepsis (25.2%), 11 septic shock patients (24.4%), and in 29 SIRS patients (13.9%). IgM hypogammaglobulinemia was documented in 55 patients with severe sepsis (12.2%), 6 septic shock patients (13.3%), and in 17 SIRS patients (8.1%). Mortality of patients with severe sepsis and normal IgG levels was significantly lower (111 patients; 32.8%) compared with those with IgG hypogammaglobulinemia (49 patients; 43.0%; p=0.001). Mortality of patients with septic shock and IgG hypogammaglobulinemia (n=5) was significantly higher compared with those with normal IgG levels (45.5% vs. 38.2%; p=0.001). Mortality of patients with severe sepsis and IgM hypogammaglobulinemia did not differ from that of patients with normal IgM levels (37.0 vs. 41.8%). Mortality of patients with septic shock and IgM hypogammaglobulinemia was significantly higher compared with those with normal IgM levels (50% vs. 38.5%; p=0.0001). This study documented relatively high incidence of hypogammaglobulinemia IgG and IgM in patients with severe sepsis, septic shock and SIRS respectively. The presence of IgG hypogammaglobulinemia in patients with severe sepsis is independent factor of mortality.


Assuntos
Agamaglobulinemia/etiologia , Sepse/complicações , Agamaglobulinemia/sangue , Agamaglobulinemia/mortalidade , Idoso , República Tcheca/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Sepse/mortalidade , Choque Séptico/complicações , Choque Séptico/mortalidade , Taxa de Sobrevida/tendências
5.
Prague Med Rep ; 112(3): 205-15, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21978781

RESUMO

UNLABELLED: Determination of mTREM-1 expression on monocytes has been investigated as a perspective diagnostic method to distinguish infectious from non-infectious etiology of the inflammation. THE AIMS OF OUR STUDY WERE: i) to investigate the expression of TREM-1 on monocytes in septic patients and in those after elective spinal surgery without infection; ii) to assess the dynamics of mTREM-1 expression on monocytes and its association with the outcome in patients with severe sepsis. Fifty two patients with severe sepsis, 20 healthy volunteers, and 20 patients after elective spinal surgery were involved in our study. TREM-1 expression on monocytes was evaluated by flow cytometry. Compared with the group of healthy adults (median 42.0, interquartile range (IQR) 30.3-76 MFI), mTREM-1 expression was increased in the group of septic patients both at entry (median 138.4, IQR 78.4-187.5 MFI) and the last examination (median 136.5, IQR 69.0-170.0 MFI) as well as in patients 24 hours after spinal surgery (median 138.5, IQR 45.3-165.5 MFI). The increase was statistically significant. mTREM-1 expression in patients undergoing spinal surgery and those with severe sepsis did not differ. TREM-1 expression on the monocytes in survivors was higher than in non-survivors (p=0.007). TREM-1 levels in septic non-surviving patients correlated weakly with TNF-α levels (r=0.38; p=0.003) and with HLA-DR/CD14 levels (r=0.38; p=0.003). Increased TREM-1 expression on monocytes is not associated exclusively with the presence of systemic infection.


Assuntos
Glicoproteínas de Membrana/metabolismo , Monócitos/metabolismo , Receptores Imunológicos/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/metabolismo , Adulto , Feminino , Antígenos HLA-DR/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Coluna Vertebral/cirurgia , Receptor Gatilho 1 Expresso em Células Mieloides , Adulto Jovem
6.
Epidemiol Mikrobiol Imunol ; 59(3): 126-32, 2010 Aug.
Artigo em Tcheco | MEDLINE | ID: mdl-20925249

RESUMO

BACKGROUND: Pernicious anaemia is an autoimmune disease that causes acquired vitamin B12 deficiency. The diagnostic process includes the detection of typical changes in the blood count, low serum levels of vitamin B12, endoscopic and histological signs of gastritis and autoantibodies against the gastric parietal cells antigen H+/K+ ATPase and intrinsic factor. OBJECTIVE: Our aims were to establish immunological tests for the detection of autoantibodies against intrinsic factor and target gastric parietal cell antigen H+/K+ ATPase and to evaluate their diagnostic benefits in patients with pernicious anaemia. MATERIAL AND METHODS: Sera from 95 patients were tested for autoantibodies against H+/K+ ATPase and intrinsic factor by multiplex Luminex assay. The results were compared with those of the immunofluorescence assay for the detection of autoantibodies against gastric parietal cells and with the diagnostic criteria. RESULTS: The autoantibodies against gastric parietal cell H+/K+ ATPase had a sensitivity of 68.2% with a specificity of 91.7% for the diagnosis of pernicious anaemia. The respective rates for the autoantibodies against intrinsic factor were 40.9% and 98.6%. The combined sensitivity and specificity rates for both autoantibodies were 86.36% and 90.28%, respectively, the combined positive predictive value was 73.08% and the combined negative predictive value was 95.59%. CONCLUSION: The detection of both autoantibodies is helpful in diagnosing pernicious anaemia and the combination of the two assays increases diagnostic sensitivity.


Assuntos
Anemia Perniciosa/diagnóstico , Autoanticorpos/sangue , ATPase Trocadora de Hidrogênio-Potássio/imunologia , Fator Intrínseco/imunologia , Células Parietais Gástricas/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Adulto Jovem
7.
Cas Lek Cesk ; 148(2): 86-90, 2009.
Artigo em Tcheco | MEDLINE | ID: mdl-19637444

RESUMO

Sepsis, the systemic inflammatory response to infection, causes high mortality in patients in non-coronary units of intensive care. The most important characteristic of sepsis is the interaction between two subjects, the macro and the microorganism, associated with the dysfunction of innate and adaptive immunity. Sepsis is understood more as a dynamic syndrome characterized by many phenomenona which are often antagonistic. The inflammation, characterizing sepsis, does not act as a primary physiological compensatory mechanism and rather oscillates between the phase of hyperinflammatory response and anergy or immunoparalysis. The elucidation of the pathogenesis of sepsis is linked to the understanding of immunopathogenetic mechanisms, which characterize the interaction between the macro and microorganisms.


Assuntos
Sepse/imunologia , Apoptose , Predisposição Genética para Doença , Humanos , Mediadores da Inflamação/metabolismo , Sepse/genética , Sepse/microbiologia , Sepse/fisiopatologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia
9.
Vnitr Lek ; 54(3): 282-6, 2008 Mar.
Artigo em Tcheco | MEDLINE | ID: mdl-18522298

RESUMO

Ormond disease - idiopathic retroperitoneal fibrosis - is a rare condition characterized in situ by the development of fibrous plaques in the retroperitoneal space and anatomicaly dependent structures. The associated encasement of both ureters and progress to hydronefrosis of the kidney are typical clinical manifestations. Less typical manifestations are possible (for example chronic periaortitis), where clinical diagnosis is more difficult. The laboratory findings are not specific for this disease and a biopsy is not always possible for anatomical reasons. In these cases, the use of positron emission tomography/computed tomography - has been found to be the solution, specifically for patients with periaortitis. Ormond disease is generally idiopathic, and secondary - to the use of certain drugs, malignant diseases, infections. Idiopathic retroperitoneal disease is thought to result from the clinical manifestation of a systemic autoimmune disease. The purpose of this article is to present two casuistics, one of a less than usual clinical manifestation. Both positron emission tomography/computed tomography were used in the diagnostics. The treatment ofOrmond disease involves the combination of surgical and immunosuppressive treatment.


Assuntos
Fibrose Retroperitoneal , Adulto , Feminino , Humanos , Masculino , Tomografia por Emissão de Pósitrons , Fibrose Retroperitoneal/complicações , Fibrose Retroperitoneal/diagnóstico , Tomografia Computadorizada por Raios X
10.
Prague Med Rep ; 109(2-3): 113-26, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19548592

RESUMO

There is no doubt that, in infectious disease, genetic predisposition plays a very important role in clinical outcome. Sepsis is a polygenic syndrome initiated by infection. A fact confounding the situation is that two factors--the macroorganism and the microorganism--are at play at the same time; hence of genotype effect must be assessed in light of their interaction. From a phylogenetic point of view, infectious disease is a companion of man throughout their life and its role in terms of function of the system of innate immunity is perceived as a beneficial one. However, the presence of a major antigen load by the infectious agent results in pathological responses at the levels of the macroorganism. Assessment of the severity of the inflammatory process on the basis of genetic predisposition is a most challenging issue. Genetic polymorphisms in the immune response to infection have been shown to be associated with clinical outcomes. The advancement of single nucleotide polymorphism (SNP) genotyping in basic genes--CD14, Toll like receptors, LBP, cytokines, cytokine receptors and coagulation factors have provided valuable information on the interaction of the macro and microorganisms. The understanding of the variation in genes and differences in response to infection may contribute to tailored diagnostic and therapeutic interventions with improved outcome in these patients.


Assuntos
Polimorfismo Genético , Sepse/genética , Citocinas/genética , Genótipo , Humanos , Farmacogenética , Receptores de Citocinas/genética , Receptores Imunológicos/genética , Sepse/tratamento farmacológico , Sepse/imunologia
13.
Epidemiol Mikrobiol Imunol ; 54(2): 54-61, 2005 Apr.
Artigo em Tcheco | MEDLINE | ID: mdl-16050543

RESUMO

BACKGROUND: Sepsis is a serious disease with a high case fatality rate. A variety of changes in the host immune responsiveness are observed in the pathogenesis of sepsis, ranging from detrimental hyperinflammation to profound immunoparalysis, i.e. acquired immunodeficiency. The level of monocyte HLA-DR expression reflects the functional status of monocytes as antigen-presenting cells and granulocyte CD64 expression is also indicative of infectious inflammation. MATERIAL AND METHODS: Monocyte HLA-DR expression and granulocyte CD64 expression were measured in 49 septic patients and 30 healthy controls using flow cytometry focused on three parameters: positive cell percentage, mean fluorescence intensity and quantitation of antibodies bound per cell (QuantiBRITE). RESULTS: The significance of both monocyte HLA-DR expression and granulocyte CD64 expression in septic patients was confirmed. Monocyte HLA-DR dramatically decreases in septic patients compared to controls, is one of the prognostic factors and correlates with C-reactive protein. In contrast, granulocyte CD64 sharply rises in patients with sepsis and correlates with mediators of systemic inflammation (procalcitonin - PCT), proinflammatory mediators (interleukin-6 - IL-6, lipopolysaccharide binding protein - LBP) and anti-inflammatory cytokines (interleukin-10 - IL10). CONCLUSION: Quantitative monocyte HLA-DR expression and granulocyte CD64 expression are useful indicators in septic patients when considered along with the panel of other markers, monitored over a period of time and in the context of the clinical course of sepsis.


Assuntos
Citometria de Fluxo , Granulócitos/imunologia , Antígenos HLA-DR/análise , Monócitos/imunologia , Receptores de IgG/análise , Sepse/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
14.
Epidemiol Mikrobiol Imunol ; 53(1): 12-6, 2004 Feb.
Artigo em Tcheco | MEDLINE | ID: mdl-15052829

RESUMO

Disorders in immune reactions represent one of the main pathogenetic mechanisms in patients of Intensive Care Units who suffer from sepsis or syndrome of systemic inflammatory response. The determination of early activation sign CD69 on T lymphocytes makes it possible to evaluate functional capacity of this cell population. The determination of other selected immunological parameters contributes to differential diagnosis of infectious and non-infectious etiology of systemic inflammatory response. The authors demonstrated lower expression of CD69 on CD3+ CD8+ lymphocytes after stimulation with phytohemagglutinin in patients with sepsis as well as patients with the syndrome of systemic inflammatory response of non-infections etiology. No statistically significant differences were proved in the concentrations of IgG, IgA and IgM, number of leukocytes, percentual representation of lymphocytes, TNF alpha production and the expression of surface sign of CD64 in both groups of patients. There were statistically significant differences in the concentrations of C3 and C4 components of complement, prealbumin and procalcitonin. The study did not show correlation between the expression of CD69 and selected immunological parameters (IgA, IgM, IgG, C3, C4, leukocytes, lymphocytes, prealbumin, procalcitonin, TNF alpha and CD64).


Assuntos
Antígenos CD/análise , Antígenos de Diferenciação de Linfócitos T/análise , Ativação Linfocitária , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Feminino , Humanos , Unidades de Terapia Intensiva , Lectinas Tipo C , Masculino , Pessoa de Meia-Idade , Síndrome de Resposta Inflamatória Sistêmica/diagnóstico , Linfócitos T/imunologia
15.
Sb Lek ; 104(1): 1-12, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14577135

RESUMO

Complete evaluation of cerebrospinal fluid proteinogram represents a routine request of the clinician in the analysis of CSF in the Czech Republic. It comprises the measurement of concentrations of acute phase proteins (CRP, orosomucoid, haptoglobin, transferrin, prealbumin), immunoglobulins (IgG, IgA, IgM), compressive markers (albumin, fibrinogen), markers of CNS tissue destruction (apolipoproteins A-I, A-II, Apo B), complement components (C3, C4), alpha-1-microglobulin, beta-2-microglobulin, and proteinase inhibitors (alpha-1-antitrypsin, antithrombin III). Therefore, 19 CSF proteins of precisely verified clinical relevance are routine parameters for the assessment of the functional state of the blood-CSF barrier, presence of the intrathecal synthesis of immunoglobulins, inflammatory changes and verification of CNS tissue destruction. Evidence of these clinically relevant and independent parameters enabled the detection of the presence of autoimmune and neuroinfective diseases of CNS, even in clinical cases where the basic CSF parameters do not express relevant changes, or they are of a bordering or non-specific character. Clinically typical and the most significant abnormalities in the CSF proteinogram represent themselves a new access to a contemporary CSF analysis. Despite the fact that assessment of CSF proteins and their analysis is quite a difficult field in laboratory medicine, it is now routinely requested and routinely performed in the Czech Republic.


Assuntos
Doenças Autoimunes do Sistema Nervoso/líquido cefalorraquidiano , Infecções do Sistema Nervoso Central/líquido cefalorraquidiano , Proteínas do Líquido Cefalorraquidiano/líquido cefalorraquidiano , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Biomarcadores/líquido cefalorraquidiano , Infecções do Sistema Nervoso Central/diagnóstico , Humanos
16.
Vnitr Lek ; 49(7): 541-7, 2003 Jul.
Artigo em Tcheco | MEDLINE | ID: mdl-12931436

RESUMO

UNLABELLED: One of the most difficult tasks in differential diagnosis of patients with septic syndrome at the Intensive Care Units is to differentiate between infection and non-infection etiology of this syndrome. In the last years, new parameters have played an important role in this area--C-reactive protein, Interleukin-6 and procalcitonin. THE AIM: Of the investigation was to compare these three parameters in differential diagnosis of the septic syndrome. THE COHORT AND METHODS: The authors examined 56 patients (17 women and 39 men, mean age being 43 and 51 years, respectively) hospitalized at the Intensive Care Units who corresponded to the criteria of the syndrome of inflammatory response, sepsis or septic shock. A total of 99 examinations were done. The samples were taken up to 24 hours after the beginning of clinical symptomatology and submitted to the laboratory within four hours. Immediately afterwards the determination of concentrations of all three parameters--C-reactive protein, interlaukin-6 and procalcitonin, were done. The results of the examinations were compared to each other as well as to the diagnosis of sepsis--the confirmed infection etiology. RESULTS: In all the evaluated parameters the authors detected significant differences between the values of entry examination and all measurements between the patients with the syndrome of systemic inflammatory response and septic shock as well as among patients with sepsis and the septic shock. Likewise, the authors confirmed significant differences between concentrations of all three parameters in comparing the patients with sepsis and those with the septic shock. Only in the case of procalcitonin there was a significant difference in concentration between patients with the syndrome of systemic inflammatory response of non-infectious etiology and those with sepsis. The concentration of procalcitonin was the only predictive marker of diagnosis with the correlation coefficient r = 0.7263, r2 = 0.5275, P < 0.00005. CONCLUSION: Calcitonin proved to be the most specific parameter in demonstrating infection etiology in patients with the septic syndrome, its predictive value being higher than that of C-reactive protein and Interleukin-6. Monitoring of calcitonin dynamism provides important information on efficiency of the applied antibiotic treatment. In patients with diagnostic uncertainties as far as the etiology of the septic syndrome is concerned; procalcitonin is the parameter of choice, while it may be supplemented with the examination of C-reactive protein.


Assuntos
Proteína C-Reativa/análise , Calcitonina/sangue , Interleucina-6/sangue , Precursores de Proteínas/sangue , Síndrome de Resposta Inflamatória Sistêmica/diagnóstico , Adulto , Biomarcadores/sangue , Peptídeo Relacionado com Gene de Calcitonina , Diagnóstico Diferencial , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Sepse/diagnóstico , Choque Séptico/diagnóstico , Síndrome de Resposta Inflamatória Sistêmica/etiologia
18.
Arch Microbiol ; 168(1): 33-8, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9211711

RESUMO

An enzyme specifically induced during 4-methylmuconolactone metabolism by Alcaligenes eutrophus JMP 134 and that exhibited muconolactone isomerizing activity was purified to homogeneity. The enzyme, involved in the isomerization of 3-methylmuconolactone had a high degree of sequence similarity with muconolactone isomerase of Alcaligenes eutrophus JMP 134 and other previously described muconolactone isomerases of the 3-oxoadipate pathway. Kinetic analysis showed that the enzyme has a substrate spectrum and a reaction mechanism similar to those of the muconolactone isomerase, but that it has distinct kinetic properties.


Assuntos
Alcaligenes/enzimologia , Transferases Intramoleculares , Isomerases/metabolismo , Lactonas/metabolismo , Alcaligenes/metabolismo , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Isoenzimas/isolamento & purificação , Isoenzimas/metabolismo , Isomerases/química , Isomerases/isolamento & purificação , Cinética , Dados de Sequência Molecular , Estrutura Molecular , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
19.
Eur J Biochem ; 237(2): 350-6, 1996 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-8647072

RESUMO

An enzyme of Alcaligenes eutrophus JMP 134 which catalyzes dechlorination of (4R, 5R)- and (4R,5S)-5-chloro-3-methyl- and (4R, 5S)-5-chloromuconolactone of principally 3-methyl-trans-, 3-methyl-cis-dienelactone and cis-dienelactone, respectively, was purified to homogeneity. The enzyme was identified as muconolactone isomerase on the basis of its high activity with muconolactone and on its high degree of sequence similarity with previously described muconolactone isomerases. Molecular mass determinations of the highly hydrophobic and heat-resistant enzyme indicated a decameric structure involving a single 10.100-kDa subunit similar to that of muconolactone isomerase of Pseudomonas putida. Kinetic analysis showed cooperative effects between the subunits during conversion of (4R, 5S)-5-chloro-3 -methylmuconolactone. (4R, 5S)-5-chloromuconolactone was the preferred substrate, over the natural substrate (4S)-muconolactone. The (4S, 5S)-structure was found to be an inhibitor of (4R, 5R)-5-chloro-3-methylmuconolactone transformation. Methylsubstitution of the substrate results in a higher affinity for the enzyme, but a drastically lower velocity, resulting in a lower specificity constant.


Assuntos
4-Butirolactona/análogos & derivados , Alcaligenes/enzimologia , Proteínas de Bactérias , Isomerases de Ligação Dupla Carbono-Carbono , Isomerases/metabolismo , 4-Butirolactona/química , 4-Butirolactona/metabolismo , Adipatos/metabolismo , Alcaligenes/genética , Sequência de Aminoácidos , Concentração de Íons de Hidrogênio , Isomerases/química , Isomerases/genética , Cinética , Lactonas/química , Lactonas/metabolismo , Dados de Sequência Molecular , Estrutura Molecular , Peso Molecular , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
20.
Eur J Biochem ; 237(2): 357-66, 1996 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-8647073

RESUMO

The stereochemistry of the four stereoforms of 5-chloro-3-methylmuconolactones could be deduced from NMR and stability data, and from the comparison with authentic (4R, 5S)-5-chloromuconolactone. Muconolactone isomerase of Alcaligenes eutrophus JMP 134 was shown to catalyze syn-elimination of hydrogen chloride from (4R, 5R)-5-chloro-3-methylmuconolactone, (4R, 5S)-5-chloro-3 -methylmuconolactone and (4R, 5S)-5-chloromuconolactone to form 3-methyl-trans-dienelactone, 3-methyl-cis-dienelactone and a 3:1 mixture of cis- and trans-dienelactone, respectively. 3-Methyl-trans-dienelactone was a substrate of pJP4-encoded dienelactone hydrolase of A. eutrophus JMP 134, whereas 3-methyl-cis-dienelactone transformation was negligible indicating a restricted substrate specificity of this enzyme. Both substrates were transformed into 3-methylmaleylacetate which in turn was a substrate for maleylacetate reductase. This compound was shown to possess a cyclic structure (4-hydroxy-3-methyl-muconolactone) under acidic conditions.


Assuntos
4-Butirolactona/análogos & derivados , Proteínas de Bactérias , Isomerases de Ligação Dupla Carbono-Carbono , 4-Butirolactona/química , 4-Butirolactona/metabolismo , 4-Butirolactona/farmacocinética , Alcaligenes/enzimologia , Biotransformação , Hidrolases de Éster Carboxílico/metabolismo , Isomerases/metabolismo , Maleatos/química , Maleatos/metabolismo , Estrutura Molecular , Estereoisomerismo , Especificidade por Substrato
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