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[PMID]:25028518
[Au] Autor:Favrot L; Lajiness DH; Ronning DR
[Ad] Endereço:From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390.
[Ti] Título:Inactivation of the Mycobacterium tuberculosis antigen 85 complex by covalent, allosteric inhibitors.
[So] Source:J Biol Chem;289(36):25031-40, 2014 Sep 05.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The rise of multidrug-resistant and totally drug-resistant tuberculosis and the association with an increasing number of HIV-positive patients developing tuberculosis emphasize the necessity to find new antitubercular targets and drugs. The antigen 85 (Ag85) complex from Mycobacterium tuberculosis plays important roles in the biosynthesis of major components of the mycobacterial cell envelope. For this reason, Ag85 has emerged as an attractive drug target. Recently, ebselen was identified as an effective inhibitor of the Ag85 complex through covalent modification of a cysteine residue proximal to the Ag85 active site and is therefore a covalent, allosteric inhibitor. To expand the understanding of this process, we have solved the x-ray crystal structures of Ag85C covalently modified with ebselen and other thiol-reactive compounds, p-chloromercuribenzoic acid and iodoacetamide, as well as the structure of a cysteine to glycine mutant. All four structures confirm that chemical modification or mutation at this particular cysteine residue leads to the disruption of the active site hydrogen-bonded network essential for Ag85 catalysis. We also describe x-ray crystal structures of Ag85C single mutants within the catalytic triad and show that a mutation of any one of these three residues promotes the same conformational change observed in the cysteine-modified forms. These results provide evidence for active site dynamics that may afford new strategies for the development of selective and potent Ag85 inhibitors.
[Mh] Termos MeSH primário: Aciltransferases/química
Antígenos de Bactérias/química
Cisteína/química
Inibidores Enzimáticos/química
[Mh] Termos MeSH secundário: Aciltransferases/genética
Aciltransferases/metabolismo
Regulação Alostérica
Anti-Inflamatórios não Esteroides/química
Anti-Inflamatórios não Esteroides/farmacologia
Antígenos de Bactérias/genética
Antígenos de Bactérias/metabolismo
Azóis/química
Azóis/farmacologia
Biocatálise/efeitos dos fármacos
Domínio Catalítico
Cloromercurobenzoatos/química
Cloromercurobenzoatos/farmacologia
Cristalografia por Raios X
Cisteína/genética
Cisteína/metabolismo
Ativação Enzimática/efeitos dos fármacos
Inibidores Enzimáticos/farmacologia
Ligações de Hidrogênio/efeitos dos fármacos
Iodoacetamida/química
Iodoacetamida/farmacologia
Modelos Moleculares
Estrutura Molecular
Mutação
Compostos Organosselênicos/química
Compostos Organosselênicos/farmacologia
Conformação Proteica
Estrutura Secundária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Anti-Inflammatory Agents, Non-Steroidal); 0 (Antigens, Bacterial); 0 (Azoles); 0 (Chloromercuribenzoates); 0 (Enzyme Inhibitors); 0 (Organoselenium Compounds); 40X2P7DPGH (ebselen); EC 2.3.- (Acyltransferases); EC 2.3.1.- (antigen 85C, Mycobacterium tuberculosis); K848JZ4886 (Cysteine); ZRH8M27S79 (Iodoacetamide)
[Em] Mês de entrada:1501
[Cu] Atualização por classe:161202
[Lr] Data última revisão:
161202
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140717
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M114.582445


  2 / 2224 MEDLINE  
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[PMID]:15096051
[Au] Autor:Qiu W; Kohen-Avramoglu R; Rashid-Kolvear F; Au CS; Chong TM; Lewis GF; Trinh DK; Austin RC; Urade R; Adeli K
[Ad] Endereço:Division of Clinical Biochemistry, Department of Laboratory Medicine and Pathobiology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8.
[Ti] Título:Overexpression of the endoplasmic reticulum 60 protein ER-60 downregulates apoB100 secretion by inducing its intracellular degradation via a nonproteasomal pathway: evidence for an ER-60-mediated and pCMB-sensitive intracellular degradative pathway.
[So] Source:Biochemistry;43(16):4819-31, 2004 Apr 27.
[Is] ISSN:0006-2960
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Co- and posttranslational regulation of apolipoprotein B (apoB) has been postulated to involve degradation by both proteasomal and nonproteasomal pathways; however, nonproteasomal mechanisms of apoB degradation are currently unknown. We have previously demonstrated an intracellular association of newly synthesized apoB with endoplasmic reticulum (ER)-60, an ER-localized protein, possessing both proteolytic and chaperone activities. In the present paper, adenoviral expression vectors containing rat ER-60 cDNA were used to achieve dose- and time-dependent overexpression of ER-60 to investigate its role in apoB100 turnover. Overexpressed ER-60 accumulated in the microsomal lumen of HepG2 cells and was associated with apoB100 in dense lipoprotein particles. Overexpression of ER-60 in HepG2 cells significantly reduced both intracellular and secreted apoB100, with no effect on the secretion of a control protein, albumin. Similar results were obtained in McA-RH7777 rat hepatoma cells. ER-60-stimulated apoB100 degradation and inhibition of apoB100 secretion were sensitive to the protease inhibitor, p-chloromercuribenzoate (pCMB), in a dose-dependent manner but were unaffected by the proteasomal or lysosomal protease inhibitors, N-acetyl-leucinyl-leucinyl-nor-leucinal, E64, and leupeptin. Interestingly, enhanced expression of ER-60 induced apoB100 fragmentation in permeabilized HepG2 cells and resulted in detection of a unique 50 kDa degradation intermediate, a process that could be inhibited by pCMB. Intracellular stability and secretion of apoB100 in primary hamster hepatocytes were also found to be sensitive to pCMB. When taken together, the data suggest an important role for ER-60 in promoting apoB100 degradation via a pCMB-sensitive process in the ER. ER-60 may act directly as a protease or may be involved indirectly as a chaperone/protein factor targeting apoB100 to this nonproteasomal and pCMB-sensitive degradative pathway.
[Mh] Termos MeSH primário: Apolipoproteínas B/antagonistas & inibidores
Apolipoproteínas B/secreção
Cloromercurobenzoatos/farmacologia
Cisteína Endopeptidases/fisiologia
Regulação para Baixo
Retículo Endoplasmático/enzimologia
Líquido Intracelular/metabolismo
Transdução de Sinais/fisiologia
[Mh] Termos MeSH secundário: Adenoviridae/genética
Animais
Apolipoproteína B-100
Apolipoproteínas B/metabolismo
Linhagem Celular
Linhagem Celular Tumoral
Permeabilidade da Membrana Celular/efeitos dos fármacos
Cricetinae
Cisteína Endopeptidases/biossíntese
Cisteína Endopeptidases/genética
Cisteína Endopeptidases/metabolismo
Inibidores de Cisteína Proteinase/farmacologia
Regulação para Baixo/efeitos dos fármacos
Regulação para Baixo/genética
Retículo Endoplasmático/genética
Vetores Genéticos
Hepatócitos/efeitos dos fármacos
Hepatócitos/enzimologia
Hepatócitos/secreção
Seres Humanos
Líquido Intracelular/enzimologia
Líquido Intracelular/secreção
Microssomos/enzimologia
Ratos
Transdução de Sinais/efeitos dos fármacos
Transdução Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Apolipoprotein B-100); 0 (Apolipoproteins B); 0 (Chloromercuribenzoates); 0 (Cysteine Proteinase Inhibitors); EC 3.4.22.- (Cysteine Endopeptidases); EC 3.4.22.- (ER-60 protease)
[Em] Mês de entrada:0408
[Cu] Atualização por classe:061115
[Lr] Data última revisão:
061115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:040421
[St] Status:MEDLINE


  3 / 2224 MEDLINE  
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[PMID]:14714473
[Au] Autor:Zherebtsov NA; Abramova IN; Shelamova SA; Popova TN
[Ad] Endereço:Voronezh State Technological Academy, Voronezh, 394017 Russia.
[Ti] Título:[Identification of catalytically active groups in inulinase from Bacillus polymyxa 722].
[Ti] Título:Identifikatsiia kataliticheski aktivnykh grupp inulinazy Bacillus polymyxa 772..
[So] Source:Prikl Biokhim Mikrobiol;39(6):619-24, 2003 Nov-Dec.
[Is] ISSN:0555-1099
[Cp] País de publicação:Russia (Federation)
[La] Idioma:rus
[Ab] Resumo:Inulinase from Bacillus polymyxa 722 hydrolyzing a polyfructosan inulin was studied. The dependence of inulinase activity on pH, measurements of pK value, calculation of ionization heat, photoinactivation with methylene blue, and inhibition with p-chloromercuribenzoate suggest that the active center of this enzyme contains imidazole and sulfhydryl groups. A possible mechanism underlying cleavage of beta-2,1-fructoside bonds in the inulin molecule with inulinase is considered.
[Mh] Termos MeSH primário: Bacillus/enzimologia
Glicosídeo Hidrolases/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
Cloromercurobenzoatos/farmacologia
Inibidores Enzimáticos/farmacologia
Glicosídeo Hidrolases/química
Concentração de Íons de Hidrogênio
Imidazóis/química
Inulina/metabolismo
Cinética
Azul de Metileno/farmacologia
[Pt] Tipo de publicação:ENGLISH ABSTRACT; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Chloromercuribenzoates); 0 (Enzyme Inhibitors); 0 (Imidazoles); 7GBN705NH1 (imidazole); 9005-80-5 (Inulin); EC 3.2.1.- (Glycoside Hydrolases); EC 3.2.1.7 (inulinase); T42P99266K (Methylene Blue)
[Em] Mês de entrada:0406
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:040113
[St] Status:MEDLINE


  4 / 2224 MEDLINE  
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[PMID]:11180979
[Au] Autor:Senthilkumar R; Reddy PN; Sharma KK
[Ad] Endereço:Mason Eye Institute, University of Missouri, One Hospital Drive, Columbia, MO 65212, USA.
[Ti] Título:Studies on trypsin-modified bovine and human lens acylpeptide hydrolase.
[So] Source:Exp Eye Res;72(3):301-10, 2001 Mar.
[Is] ISSN:0014-4835
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Acylpeptide hydrolase removes the N -acetylated amino acids from the peptide substrates but not from intact proteins. Cleavage between amino acid residues 203--204 of the native acylpeptide hydrolase results in the formation of a 55 kDa truncated active enzyme in the bovine lens, in vivo. In this study we explored the hydrolytic properties of the truncated enzyme using lens beta- and gamma-crystallins as substrates. SDS--PAGE analysis indicated that the beta B2-crystallin was cleaved by truncated acylpeptide hydrolase into several protein fragments (10--26 kDa). No cleavage of the gamma-crystallins was observed under similar conditions. Both the acylpeptide hydrolase activity and the protease activity of the 55 kDa enzyme were completely inhibited by diisopropylfluorophosphate, p -chloromercuribenzoate and ebelactone, and moderately inhibited by N -tosyl phenylalanine chloromethyl ketone. SDS--PAGE analysis followed by fluorography of ((3)H) diisopropylfluorophosphate labeled human lens acylpeptide hydrolase preparation showed the presence of the 55 kDa truncated form of the enzyme, as observed in the bovine lens. The peptide (d)-AIKGDQFL-NH(2)--the amino acid sequence 200--207 of the native bovine acylpeptide hydrolase with an in vivo cleavage site of native protein--was hydrolysed by the lens protease(s) suggesting that the in vivo generation of the 55 kDa acylpeptide hydrolase may be mediated through a proteolytic processing. The protease(s) responsible for the cleavage of this peptide was inhibited by diisopropylfluorophosphate and p -chloromercuribenzoate.
[Mh] Termos MeSH primário: Cristalino/enzimologia
Peptídeo Hidrolases/química
Tripsina/química
[Mh] Termos MeSH secundário: Adolescente
Adulto
Idoso
Idoso de 80 Anos ou mais
Animais
Bovinos
Cloromercurobenzoatos/farmacologia
Cristalinas/metabolismo
Eletroforese em Gel de Poliacrilamida
Inibidores Enzimáticos/farmacologia
Seres Humanos
Hidrólise
Isoflurofato/farmacologia
Lactonas/farmacologia
Meia-Idade
Fragmentos de Peptídeos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
[Nm] Nome de substância:
0 (Chloromercuribenzoates); 0 (Crystallins); 0 (Enzyme Inhibitors); 0 (Lactones); 0 (Peptide Fragments); 12UHW9R67N (Isoflurophate); 76808-16-7 (ebelactone A); EC 3.4.- (Peptide Hydrolases); EC 3.4.21.4 (Trypsin)
[Em] Mês de entrada:0105
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:010222
[St] Status:MEDLINE


  5 / 2224 MEDLINE  
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[PMID]:10647703
[Au] Autor:Yang SJ; An JY; Shim JO; Park CH; Huh IH; Sohn UD
[Ad] Endereço:Department of Pharmacology, College of Pharmacy, Chung Ang University, Seoul, Republic of Korea.
[Ti] Título:The mechanism of contraction by 2-chloroadenosine in cat detrusor muscle cells.
[So] Source:J Urol;163(2):652-8, 2000 Feb.
[Is] ISSN:0022-5347
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:PURPOSE: Four adenosine receptors (ARs), designated A1AR (A1 adenosine receptor), A2aAR (A2a adenosine receptor), A2bAR (A2b adenosine receptor), and A3AR (A3 adenosine receptor), have been cloned from various species, but the contraction mechanism via A1ARs in cat detrusor muscle cell is not well known. MATERIALS AND METHODS: We examined the cellular mechanism using an A1AR agonist 2-chloroadenosine (2-CA) in cat detrusor cell isolated by enzymatic digestion. To examine which phospholipase mediates the contraction, we used phospholipase inhibitors. RESULTS: The adenosine analog potency order is R-N6-phenylisopropyladenosine (R-PIA) > 5'-N-ethylcarbosamine adenosine (NECA) > 2-chloroadenosine (2-CA) > S-N6-phenylisopropyladenosine (S-PIA). The ratio of equi-effective concentrations of R-PIA/S-PIA was 58.2. 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 300 nM) shifted to the right the concentration-response curves of 2-CA. These results indicate A1ARs mediate 2-CA induced contraction in cat detrusor muscle. G proteins (Gi1, Gi2, Gi3, Go, Gs, and Gq) in cat detrusor muscle were detected by immunoblot analysis. Pertussis toxin (PTX) inhibited 2-CA induced contraction. In permeabilized cells, antibodies against Galphai3 antagonized 2-CA induced contraction, suggesting that the contraction is mediated by Gi3 protein. A phosphatidylinositol-specific phospholipase C (PLC) inhibitor, neomycin, reduced 2-CA induced contraction, but a phospholipase D (PLD) inhibitor, p-chloromercuribenzoic acid, and a phospholipase A2 (PLA2) inhibitor, dimethyl-eicosa-dienoic acid (DEDA), had no effect. We found the presence of the main PLC isozymes, PLC-beta1, PLC-beta3, and PLC-gamma1. 2-CA induced contraction in permeabilized cells was inhibited by PLC-beta3 but not by PLC-beta1 or PLC-gamma1 antibody. These results imply that A1ARs are coupled to PLC-beta3 via PTX-sensitive Gi3 protein. Sr2+ medium and thapsigargin, which replaces intracellular Ca2+ and deplete intracellular calcium stores respectively, inhibited 2-CA induced contraction. CONCLUSIONS: These results suggest that A1ARs mediating 2-CA induced contraction exist in cat detrusor muscle and the contraction depends on a PTX-sensitive Gi3 protein, PLC-beta3 and the release of intracellular Ca2+.
[Mh] Termos MeSH primário: 2-Cloroadenosina/farmacologia
Contração Muscular/efeitos dos fármacos
Músculo Liso/efeitos dos fármacos
Músculo Liso/fisiologia
Bexiga Urinária/efeitos dos fármacos
Bexiga Urinária/fisiologia
[Mh] Termos MeSH secundário: Animais
Gatos
Cloromercurobenzoatos/farmacologia
Proteínas de Ligação ao GTP/fisiologia
Toxina Pertussis
Antagonistas de Receptores Purinérgicos P1
Fatores de Virulência de Bordetella/farmacologia
Xantinas/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Chloromercuribenzoates); 0 (Purinergic P1 Receptor Antagonists); 0 (Virulence Factors, Bordetella); 0 (Xanthines); 146-77-0 (2-Chloroadenosine); 9PTP4FOI9E (1,3-dipropyl-8-cyclopentylxanthine); EC 2.4.2.31 (Pertussis Toxin); EC 3.6.1.- (GTP-Binding Proteins)
[Em] Mês de entrada:0002
[Cu] Atualização por classe:161124
[Lr] Data última revisão:
161124
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:000127
[St] Status:MEDLINE


  6 / 2224 MEDLINE  
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[PMID]:9720226
[Au] Autor:Shin HH; Choi HS
[Ad] Endereço:Department of Microbiology, University of Ulsan, Korea.
[Ti] Título:Purification and characterization of cysteine protease from Pleurotus ostreatus.
[So] Source:Biosci Biotechnol Biochem;62(7):1416-8, 1998 Jul.
[Is] ISSN:0916-8451
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Cysteine protease activity in mycelial culture increased 7.7-fold after fruit body formation in Pleurotus ostreatus, using the Leu pNA (LPNA) cleavage assay. The enzyme was purified from fruit bodies and its M(r) was 97,000 by gel filtration and 48,500 by SDS-PAGE, indicating that it is a dimer. The enzyme was sensitive to iodoacetic acid, p-chloromercuribenzoate, N-ethylmaleimide, and HgCl2. The sequence of the first 9 N-terminal amino acids of cysteine protease was ASGLXXAIL.
[Mh] Termos MeSH primário: Basidiomycota/enzimologia
Cisteína Endopeptidases/isolamento & purificação
[Mh] Termos MeSH secundário: Cloromercurobenzoatos/química
Cromatografia em Gel
Cisteína Endopeptidases/química
Dimerização
Eletroforese em Gel de Poliacrilamida
Etilmaleimida/química
Concentração de Íons de Hidrogênio
Iodoacetatos/química
Ácido Iodoacético
Cloreto de Mercúrio/química
Peso Molecular
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Chloromercuribenzoates); 0 (Iodoacetates); 53GH7MZT1R (Mercuric Chloride); EC 3.4.22.- (Cysteine Endopeptidases); O3C74ACM9V (Ethylmaleimide); WF5188V710 (Iodoacetic Acid)
[Em] Mês de entrada:9809
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:980828
[St] Status:MEDLINE


  7 / 2224 MEDLINE  
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[PMID]:9671510
[Au] Autor:Behrens W; Alexiev U; Mollaaghababa R; Khorana HG; Heyn MP
[Ad] Endereço:Biophysics Group, Department of Physics, Freie Universität Berlin, Germany.
[Ti] Título:Structure of the interhelical loops and carboxyl terminus of bacteriorhodopsin by X-ray diffraction using site-directed heavy-atom labeling.
[So] Source:Biochemistry;37(29):10411-9, 1998 Jul 21.
[Is] ISSN:0006-2960
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The positions of single amino acids in the interhelical loop regions and the C-terminal tail of bacteriorhodopsin (bR) were investigated by X-ray diffraction using site-directed heavy-atom labeling. Since wild-type bR does not contain any cysteines, appropriate cysteine mutants were produced with a unique sulfhydryl group at specific positions. These sites were then labeled with mercury using the sulfhydryl specific reagent p-chloromercuribenzoate (p-CMB). The cysteine mutants D96A/V101C, V130C, A160C, and G231C were derivatized with labeling stoichiometries of 0.93 +/- 5%, 0.85 +/- 5%, 0.79 +/- 7%, and 0.77 +/- 8%, respectively (Hg per bR). No incorporation was observed with wild-type bR under the same conditions. All mutants and heavy-atom derivatives were fully active as judged by the kinetics of the photocycle and of the proton release and uptake. Moreover, the unit cell dimensions of the two-dimensional P3 lattice were unchanged by the mutations and the derivatization. This allowed the position of the mercury atoms, projected onto the plane of the membrane, to be calculated from the intensity differences in the X-ray diffraction pattern between labeled and unlabeled samples using Fourier difference methods. The X-ray diffraction data were collected at room temperature from oriented purple membrane films at 100% relative humidity without the use of dehydrating solvents. These native conditions of temperature, humidity, and solvent are expected to preserve the structure of the surface-exposed loops. Sharp maxima corresponding to a single mercury atom were found in the difference density maps for D96A/V101C and V130C. Residues 101 and 130 are in the short loops connecting helices C/D and D/E, respectively. No localized difference density was found for A160C and G231C. Residue 160 is in the longer loop connecting helices E and F, whereas residue 231 is in the C-terminal tail. Residues 160 and 231 are apparently in a more disordered and mobile part of the structure.
[Mh] Termos MeSH primário: Bacteriorodopsinas/química
Cloromercurobenzoatos/metabolismo
Estrutura Secundária de Proteína
[Mh] Termos MeSH secundário: Alanina/genética
Sequência de Aminoácidos
Ácido Aspártico/genética
Bacteriorodopsinas/genética
Bacteriorodopsinas/metabolismo
Cisteína/genética
Glicina/genética
Marcação por Isótopo/métodos
Dados de Sequência Molecular
Mutagênese Sítio-Dirigida
Fotoquímica
Bombas de Próton/química
Espectrofotometria Ultravioleta
Valina/genética
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
[Nm] Nome de substância:
0 (Chloromercuribenzoates); 0 (Proton Pumps); 30KYC7MIAI (Aspartic Acid); 53026-44-1 (Bacteriorhodopsins); HG18B9YRS7 (Valine); K848JZ4886 (Cysteine); OF5P57N2ZX (Alanine); TE7660XO1C (Glycine)
[Em] Mês de entrada:9808
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:980722
[St] Status:MEDLINE


  8 / 2224 MEDLINE  
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[PMID]:9597757
[Au] Autor:Cunningham DF; O'Connor B
[Ad] Endereço:School of Biological Sciences, Dublin City University, Ireland.
[Ti] Título:A study of prolyl endopeptidase in bovine serum and its relevance to the tissue enzyme.
[So] Source:Int J Biochem Cell Biol;30(1):99-114, 1998 Jan.
[Is] ISSN:1357-2725
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Prolyl endopeptidase (PE) belongs to a group of enzymes that specifically recognise the imino acid proline. The characterisation of bovine serum PE was undertaken so that its relationship to its tissue counterparts could be considered. Using various chromatographic methods, PE was partially purified from bovine serum. This preparation was deemed to be enzymatically pure, based on its failure to hydrolyse a wide range of fluorimetric substrates. A native molecular mass of 69.7 kDa was estimated for the enzyme. PE was optimally active at pH 8.0-8.5, demonstrated a preference for phosphate buffer and remained stable over a pH range of 5.0-9.0. A narrowly focused optimal assay temperature of 37 degrees C was evident. Functional reagent studies indicated that this enzyme was a serine protease with a cysteine residue located near or at the active site. The enzyme was also sensitive to heavy metal inhibition. Substrate specificity investigations revealed that the bioactive peptides angiotensin II, bradykinin, luliberin and substance P were hydrolysed by the enzyme preparation, but lower specificities were evident towards these peptides in comparison with the enzyme's tissue counterparts. Specific inhibitor studies, using a range of compounds previously untested against a single PE source, indicated that alpha-ketobenzothiazole was the most effective PE inhibitor, with an IC50 value of 41 pM. In conclusion, the results presented in this paper indicate that bovine serum PE shares many of the characteristics associated with its tissue counterparts, with the exception of its specificity towards certain bioactive peptides.
[Mh] Termos MeSH primário: Inibidores Enzimáticos/farmacologia
Metais/farmacologia
Serina Endopeptidases/sangue
Serina Endopeptidases/efeitos dos fármacos
[Mh] Termos MeSH secundário: Angiotensina II/metabolismo
Animais
Ligação Competitiva
Bradicinina/metabolismo
Bovinos
Cloromercurobenzoatos/farmacologia
Cumarínicos/química
Cumarínicos/farmacologia
Estabilidade Enzimática/efeitos dos fármacos
Estabilidade Enzimática/fisiologia
Fluorometria
Hormônio Liberador de Gonadotropina/metabolismo
Concentração de Íons de Hidrogênio
Peso Molecular
Neuropeptídeos/metabolismo
Serina Endopeptidases/química
Substância P/metabolismo
Especificidade por Substrato
Ácido p-Cloromercurobenzoico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Chloromercuribenzoates); 0 (Coumarins); 0 (Enzyme Inhibitors); 0 (Metals); 0 (Neuropeptides); 11128-99-7 (Angiotensin II); 33507-63-0 (Substance P); 33515-09-2 (Gonadotropin-Releasing Hormone); 59-85-8 (p-Chloromercuribenzoic Acid); 68542-93-8 (N-carbobenzoxyglycyl-prolyl-4-methylcoumarinyl amide); EC 3.4.21.- (Serine Endopeptidases); EC 3.4.21.26 (prolyl oligopeptidase); S8TIM42R2W (Bradykinin)
[Em] Mês de entrada:9807
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:980523
[St] Status:MEDLINE


  9 / 2224 MEDLINE  
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Fotocópia
[PMID]:9576484
[Au] Autor:Park JH; Edwards MR; Schofield PJ
[Ad] Endereço:School of Biochemistry and Molecular Genetics, University of New South Wales, Sydney, Australia. parkjh@u.washington.edu
[Ti] Título:Swelling detection for volume regulation in the primitive eukaryote Giardia intestinalis: a common feature of volume detection in present-day eukaryotes.
[So] Source:FASEB J;12(7):571-9, 1998 May.
[Is] ISSN:0892-6638
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:It is increasingly evident that cell swelling is associated with the triggering of many biological processes, including progression of the cell cycle, hormonal response, and gene expression. However, the mechanism by which cell swelling is initially sensed and converted into intracellular signals is still ill-defined. We report here an early event in the detection of cell swelling and initiation of the volume regulatory response in Giardia intestinalis, an ancient representative of the eukaryotic kingdom. Giardial cell swelling, irrespective of the extent, was sensed at a cell volume of 1.06 x isosmotic volume (the threshold volume), at which the transition of the volume regulatory transport system from the 'resting' to the 'open' state occurred. Irreversible modification by p-chloromercuribenzoate (pCMB) and N-ethylmaleimide (NEM) of reduced thiols affected the threshold volume, but in opposing manners: pCMB increased the threshold volume to 1.14 x and NEM decreased to 0.85 x isosmotic volume. The simple modification of the threshold volume by NEM caused a drastic reduction of giardial cell volume under isosmotic conditions, with a process strikingly similar to the opening of mitochondrial permeability transition pore, a causative event in stress-induced programmed cell death. Substantial evidence supports the hypothesis that modulation of the membrane thiol moieties at the threshold volume, causing the 'all-or-nothing' type of swelling detection, represents the event linking cell swelling to the second messenger systems for volume regulation in present eukaryotes. Pathophysiological implications of alteration of the threshold volume are discussed.
[Mh] Termos MeSH primário: Tamanho Celular/fisiologia
Giardia lamblia/fisiologia
[Mh] Termos MeSH secundário: Alanina/metabolismo
Aminoácidos/metabolismo
Animais
Apoptose
Tamanho Celular/efeitos dos fármacos
Cloromercurobenzoatos/farmacologia
Etilmaleimida/farmacologia
Células Eucarióticas
Giardia lamblia/efeitos dos fármacos
Cinética
Concentração Osmolar
Estresse Fisiológico
Fatores de Tempo
Ácido p-Cloromercurobenzoico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acids); 0 (Chloromercuribenzoates); 59-85-8 (p-Chloromercuribenzoic Acid); O3C74ACM9V (Ethylmaleimide); OF5P57N2ZX (Alanine)
[Em] Mês de entrada:9805
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:980512
[St] Status:MEDLINE


  10 / 2224 MEDLINE  
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Fotocópia
[PMID]:9540790
[Au] Autor:Huang HS; Kabashima T; Ito K; Yin CH; Nishiya Y; Kawamura Y; Yoshimoto T
[Ad] Endereço:School of Pharmaceutical Sciences, Nagasaki University, Japan.
[Ti] Título:Thermostable glycerol kinase from Thermus flavus: cloning, sequencing, and expression of the enzyme gene.
[So] Source:Biochim Biophys Acta;1382(2):186-90, 1998 Feb 17.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The thermostable glycerol kinase (EC 2.7.1.30) gene from Thermus flavus was cloned and expressed in Escherichia coli DH5 alpha. An open reading frame of 1488 bp for the glycerol kinase gene (glpK) starting with an ATG methionine codon was found, which encodes a protein of 496 amino acid residues whose calculated molecular weight is 54,835. The amino acid sequence of T. flavus glycerol kinase is 80.6% and 64.1% identical with those of Bacillus subtilis and E. coli. Transformants of E. coli DH5 alpha harboring plasmid pGYK12 with a 1505 bp chromosomal DNA fragment containing the T. flavus glycerol kinase gene showed about 23.8-fold higher glycerol kinase activity than T. flavus.
[Mh] Termos MeSH primário: Glicerol Quinase/química
Thermus/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas Arqueais/química
Sequência de Bases
Cloromercurobenzoatos/farmacologia
Clonagem Molecular
Sequência Consenso/genética
Estabilidade Enzimática
Expressão Gênica/genética
Dados de Sequência Molecular
Proteínas Recombinantes
Análise de Sequência de DNA
Homologia de Sequência de Aminoácidos
Ácido p-Cloromercurobenzoico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Chloromercuribenzoates); 0 (Recombinant Proteins); 59-85-8 (p-Chloromercuribenzoic Acid); EC 2.7.1.30 (Glycerol Kinase)
[Em] Mês de entrada:9805
[Cu] Atualização por classe:161126
[Lr] Data última revisão:
161126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:980416
[St] Status:MEDLINE



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