Assuntos
Aneurisma da Aorta Torácica/complicações , Doenças da Aorta/patologia , Dissecção Aórtica/complicações , Fístula Esofágica/patologia , Fístula Vascular/patologia , Idoso , Dissecção Aórtica/patologia , Aneurisma da Aorta Torácica/patologia , Doenças da Aorta/etiologia , Fístula Esofágica/etiologia , Esofagoscopia , Evolução Fatal , Feminino , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/patologia , Humanos , Choque/etiologia , Tomografia Computadorizada por Raios X , Úlcera/etiologia , Úlcera/patologia , Fístula Vascular/etiologiaRESUMO
The Fas-Fas ligand system is involved in apoptosis. The mouse anti-human Fas monoclonal antibody HFE7A (m-HFE7A) has a potential use in human therapy against autoimmune diseases such as rheumatoid arthritis. Information on the three-dimensional structure is essential for antibody humanization. Crystals of an antigen-binding fragment (Fab) of m-HFE7A were obtained by the hanging-drop vapour-diffusion method using sodium citrate as a precipitant and 2-methyl-2,4-pentanediol as an additive. Fast optimization to produce single crystals suitable for X-ray analysis was achieved by the streak-seeding technique. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 43.4, b = 74.0, c = 133.8 A. The crystals diffract at least to 2.5 A resolution.
Assuntos
Anticorpos Monoclonais/química , Fragmentos Fab das Imunoglobulinas/química , Animais , Anticorpos Monoclonais Murinos , Cristalização , Cristalografia por Raios X , Humanos , Camundongos , Conformação ProteicaRESUMO
Four patients (three males and one female) were diagnosed as myeloid/natural killer (NK) cell precursor acute leukemia in our department. Two patients showed the extramedullary involvement at initial presentation. Leukemic cells expressed CD7, CD33, CD45 and CD56 in all patients. Additionally, CD13, CD34, HLA-DR, cytoplasmic CD3 and myeloperoxidase were expressed in some patients. Trisomy 10 was found in two patients, which has not been reported in this disease. Therefore, myeloid/NK cell precursor acute leukemia might be rather heterogeneous especially in chromosomal abnormality though it seemed to constitute the distinct clinical entity among acute myeloid leukemia of M0 subtype.
Assuntos
Células da Medula Óssea/imunologia , Células Matadoras Naturais/imunologia , Leucemia/patologia , Doença Aguda , Adulto , Idoso , Antígenos CD/imunologia , Feminino , Humanos , Imunofenotipagem , Leucemia/imunologia , Masculino , Pessoa de Meia-IdadeRESUMO
A 58-year-old man was admitted to our hospital in November 1992 because of fever and arthralgia. He was given a diagnosis of acute lymphoblastic leukemia and treated with an Ad-VP regimen, which resulted in complete remission. After two courses of consolidation therapy and intrathecal (IT) injections of methotrexate, Ara-C, and prednisolone the patient received high-dose Ara-C plus VP-16 followed by recombinant human G-CSF for the collection of peripheral blood stem cells. However, he relapsed with the appearance of leukemic cells in cerebrospinal fluid (CSF), and was accordingly given IT injections 8 more times. After the disappearance of leukemic cells from CSF, the patient received a peripheral blood stem cell transplant (PBSCT) and achieved rapid hematopoietic recovery. However, he suffered mental aberrations and loss of consciousness 9 days after PBSCT. Proton magnetic resonance spectroscopy (1H-MRS) disclosed severe necrosis due to leukoencephalopathy in the frontal lobe and invasion of leukemic cells around the lateral ventricles. The patient did not receive any therapy for neurological symptoms because of severe necrosis in the frontal lobe, and died of bone marrow relapse in April 1995. MRS is useful for the discrimination of leukoencephalopathy from leukemic cell invasion.
Assuntos
Encefalopatias/diagnóstico , Encéfalo/patologia , Infiltração Leucêmica/patologia , Espectroscopia de Ressonância Magnética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Antineoplásicos/efeitos adversos , Encefalopatias/induzido quimicamente , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaçõesRESUMO
A novel endothelin-converting enzyme (ECE) inhibitor, B-90063, was isolated from the culture supernatant of the newly discovered marine bacterium Blastobacter sp. SANK 71894. Based on spectral analyses and chemical reactions, the structure of B-90063 was determined to be bis[6-formyl-4-hydroxy-2-(2'-n-pentyloxazol-4'-yl)-4-pyridon -3-yl]-disulfide (1a). Human and rat ECEs were inhibited more potently by B-90063, with respective IC50 values of 1.0 and 3.2 microM, than were other neutral endopeptidases such as NEP and type-I and -IV collagenases. B-90063 also inhibited the binding of ET-1 to rat ET(A) and bovine ET(B) receptors, though its antagonistic activities were weak. B-90063, thus, may abolish the physiological actions of endothelins through the ECE inhibitory and receptor antagonistic mechanisms.
Assuntos
Ácido Aspártico Endopeptidases/antagonistas & inibidores , Bactérias Gram-Negativas/metabolismo , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Piridonas/química , Piridonas/farmacologia , Sulfetos/química , Sulfetos/farmacologia , Animais , Bovinos , Endotelina-1/efeitos dos fármacos , Endotelina-1/metabolismo , Enzimas Conversoras de Endotelina , Fermentação , Bactérias Gram-Negativas/química , Bactérias Gram-Negativas/classificação , Humanos , Espectroscopia de Ressonância Magnética , Inibidores de Metaloproteinases de Matriz , Metaloendopeptidases , Estrutura Molecular , Neprilisina/antagonistas & inibidores , Inibidores de Proteases/isolamento & purificação , Piridonas/isolamento & purificação , Ratos , Receptor de Endotelina A , Receptor de Endotelina B , Receptores de Endotelina/efeitos dos fármacos , Receptores de Endotelina/metabolismo , Relação Estrutura-Atividade , Sulfetos/isolamento & purificação , Microbiologia da ÁguaRESUMO
A-53930A, B and C, which inhibit N-type Ca2+ channels, were isolated from the culture broth of Streptomyces vinaceusdrappus SANK 62394. A-53930A and B were new compounds which contained a carbamoyl group on the 6-hydroxyl group of the D-gulosamine part of streptothricin. A-53930C was identical to streptothricin B. A-53930A, B and C inhibited [125I]omega-conotoxin MVIIA binding to N-type Ca2+ channels (IC50= 0.17, 0.091 and 0.071 microM), but did not inhibit [3H]PN200-110 binding to L-type Ca2+ channels (IC50 > 50 microM). These compounds also inhibited [3H]norepinephrine release from chick cerebral cortex synaptosomes (IC50=91.0, 20.6 and 39.5 microM), indicating these compounds selectively block N-type Ca2+ channels which are important for neurotransmitter release. It was also revealed that although A-53930C had antimicrobial activity against gram-negative and -positive bacteria and fungi, A-53930A and B showed weak activity only against gram-negative bacteria.
Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Streptomyces/química , Estreptotricinas/farmacologia , ômega-Conotoxinas , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/isolamento & purificação , Bloqueadores dos Canais de Cálcio/toxicidade , Galinhas , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Técnicas In Vitro , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Norepinefrina/metabolismo , Peptídeos/metabolismo , Ligação Proteica , Coelhos , Ratos , Streptomyces/classificação , Estreptotricinas/química , Estreptotricinas/isolamento & purificação , Estreptotricinas/toxicidade , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismoRESUMO
Novel endothelin antagonists, nahocols A, A1, B, C, D1 and D2, and isonahocols D1 and D2, were isolated from the brown alga, Sargassum autumnale. Their structures were determined through detailed analysis of NMR spectra and chemical reactions. Nahocols have an aryl prenyl ether structure, which are speculated to be biogenetic precursors of the ubiquitous prenyl hydroquinones or prenyl benzoquinones in the plant and animal kingdoms.
Assuntos
Endotelina-1/antagonistas & inibidores , Phaeophyceae/química , Fenóis/farmacologia , Estrutura Molecular , Fenóis/química , Análise EspectralRESUMO
Cytokine-induced neutrophil chemoattractant (CINC/Gro) is a chemotactic factor for neutrophils in the rat and a member of the CXC chemokine family. The refined three-dimensional structure of CINC/Gro was derived with the aid of heteronuclear magnetic resonance spectroscopy and a hybrid method of distance geometry and simulated annealing. The backbone atomic r.m.s. differences for 19 structures about the mean coordinates for residues 7 to 70 are 0.69+/-0.15 A for the dimer and 0.56+/-0.13 A for the monomer. The N terminal region containing an ELR sequence, an essential motif for chemotactic activity, is disordered in solution, as in other CXC chemokines. The dimer structure consists of a six-stranded anti-parallel beta sheet with two C-terminal alpha helices on the beta sheet. The overall dimer structure of CINC/Gro is similar to that of human MGSA, though the backbone r.m.s.d.s between CINC/Gro and the two MGSA structures were high (1.81 and 2.34 A for the monomer) in spite of the high sequence homology (67%). The major difference resides in the relative position of the C-terminal alpha helix with respect to the beta sheet. This results in a difference of interhelical distances in the dimer: wider (15 A) in CINC/Gro, as in IL-8, than in MGSA (11.7 and 10 A).
Assuntos
Quimiocinas CXC , Fatores Quimiotáticos/química , Substâncias de Crescimento/química , Peptídeos e Proteínas de Sinalização Intercelular , Animais , Quimiocina CXCL1 , Quimiocinas/química , Humanos , Interleucina-8/química , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica , Ratos , Proteínas Recombinantes/químicaRESUMO
We analyzed the expression of Thy-1 (CD90) antigen on CD34+ bone marrow mononuclear cells (BMMNC) obtained from 25 patients with myelodysplastic syndrome (MDS) by two-color flow cytometry. Five of nine patients (55.6%) with refractory anemia with excess of blasts (RAEB) and two of 16 (12.5%) with RAEB in transformation (RAEB-t) showed more than 20% of Thy-1 expression of their CD34+ BMMNC. Regarding chromosomal abnormalities, -5/5q- or -18 might be correlated with the expression of Thy-1 on CD34+ BMMNC in MDS. Nine patients were analyzed twice, once before and once after leukemic transformation and showed no significant change in Thy-1 expression. These results show that Thy-1 was expressed on CD34+ BMMNC in certain patients with MDS before leukemic transformation and that it was maintained during the disease progression. In contrast, expression of Thy-1 did not seem essential to the leukemic transformation in MDS though the patients with high Thy-1 expression might have poorer prognosis compared with those with low Thy-1 expression.
Assuntos
Citometria de Fluxo , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Antígenos Thy-1/biossíntese , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Refratária com Excesso de Blastos/metabolismo , Anemia Refratária com Excesso de Blastos/patologia , Antígenos CD34/análise , Antígenos CD34/imunologia , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Transformação Celular Neoplásica/metabolismo , Aberrações Cromossômicas/patologia , Transtornos Cromossômicos , Feminino , Humanos , Masculino , Metáfase , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/patologiaRESUMO
Rat CINC/Gro is a 72 residue chemotactic factor of neutrophils, and a member of the CXC chemokine family, that includes IL-8 and MGSA/GRO. Although the three-dimensional structure of CINC/Gro had previously been determined to be that of a dimer with 200 mM NaCl, it was shown on both ultracentrifugation analysis and 1H-NMR spectral analysis that CINC/Gro exists mainly as a monomer at a physiological concentration, similar to other proteins belonging to this family. By reducing the NaCl concentration, the equilibrium could be shifted to the monomer, making it possible to observe the monomer and dimer resonances in 1H-NMR spectra. There were no significant chemical shift changes of alpha protons in the beta sheet between the monomer and dimer, suggesting that the beta sheet structure was retained in the monomer. Instead, the chemical shift changes of a protons were significant at I18 and K21, which are located in the long loop region interacting with the alpha helix, and V59 at the beginning of the a helix, indicating structural changes in the relative positions of the alpha helix and beta sheet.
Assuntos
Quimiocinas CXC , Fatores Quimiotáticos/química , Substâncias de Crescimento/química , Peptídeos e Proteínas de Sinalização Intercelular , Animais , Fenômenos Químicos , Físico-Química , Quimiocina CXCL1 , Dimerização , Hidrogênio , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Ressonância Magnética , Ligação Proteica , Conformação Proteica , Ratos , Cloreto de Sódio , Temperatura , Ultracentrifugação/métodosRESUMO
Recently, the ligand for c-mpl has been cloned and initial studies have shown it to be the platelet regulatory factor, thrombopoietin (TPO). To elucidate the role of TPO in the reconstitution of megakaryopoiesis and platelet production after stem cell transplantation, we measured serum TPO levels in nine patients undergoing autologous peripheral blood stem cell transplantation (PBSCT) and in healthy volunteers. Serum TPO levels significantly correlated with the degree of peripheral thrombocytopenia and a strong inverse correlation between serum TPO level and platelet count was observed (r = -0.700, P < 0.001). Serum TPO levels began to rise as the platelet count decreased after chemotherapy, TPO levels peaked at over 25.00 fmoles/ml between days 0 and 10; TPO levels then decreased gradually as the platelet count began to rise. One patient with multiple myeloma received purified CD34+ peripheral blood stem cells. No difference was observed in the kinetics of serum TPO levels between unfractionated and purified PBSCT. These observations suggest that TPO plays a critical role in the reconstitution of megakaryopoiesis and platelet production after PBSCT.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Trombopoetina/sangue , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Hematopoese/fisiologia , Humanos , Cinética , Masculino , Megacariócitos , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/terapia , Contagem de Plaquetas , Trombocitopenia/sangue , Transplante AutólogoRESUMO
Schizostatin (1) has been isolated as a potent and selective inhibitor of squalene synthase. Its structure has been determined using spectroscopic methods: the compound is shown to be a diterpenoid which has a trans-dicarboxylic acid moiety. Total synthesis of schizostatin (1) was achieved by the highly regio- and stereoselective coupling reaction of an allylic bromide with a barium reagent. The Z-isomer 16 was also prepared using the stereoselective syn-addition of an organocopper reagent to acetylenedicarboxylate.
Assuntos
Inibidores Enzimáticos/química , Farnesil-Difosfato Farnesiltransferase/antagonistas & inibidores , Ácidos Graxos/química , Fumaratos/química , Inibidores Enzimáticos/síntese química , Ácidos Graxos/síntese química , Fumaratos/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Schizophyllum/metabolismo , Espectrometria de Massas de Bombardeamento Rápido de ÁtomosRESUMO
A novel acyl-CoA : cholesterol acyltransferase (ACAT) inhibitor, designated epi-cochlioquinone A has been isolated from the fermentation broth of Stachybotrys bisbyi SANK 17777. The molecular formula, physicochemical properties, NMR spectroscopic analysis and X-ray crystallographic analysis revealed that this compound was a stereoisomer of cochlioquinone A, which has been previously reported as a nematocidal agent. It inhibited ACAT activity in an enzyme assay using rat liver microsomes with an IC50 value of 1.7 microM. However, it showed about 10-fold less potent inhibitory effect on plasma lecithin cholesterol acyltransferase (LCAT) than on ACAT. In addition, it inhibited in vivo cholesterol absorption in rats by 50% at 75 mg/kg.
Assuntos
Benzoquinonas/isolamento & purificação , Esterol O-Aciltransferase/antagonistas & inibidores , Animais , Antinematódeos , Benzoquinonas/química , Benzoquinonas/farmacologia , Fermentação , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Stachybotrys , EstereoisomerismoRESUMO
Although the administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) enhances myeloid engraftment and reduces infectious morbidity after autologous and allogeneic bone marrow transplantations, the effect of rhG-CSF on neutrophil recovery in autologous blood stem cell transplantation (ABSCT) is controversial. We previously demonstrated that a low dose, delivered subcutaneously, of rhG-CSF (50 micrograms/m2) accelerates neutrophil recovery in ABSCT, but the optimal dosage of rhG-CSF is not known. To elucidate the effect of rhG-CSF on neutrophil recovery, we determined serum levels of endogenous and exogenously administered G-CSF in 24 patients receiving ABSCT. Of these, five received bolus subcutaneous injection of 50 micrograms/m2 rhG-CSF, 10 received 150 micrograms/m2, and nine received no rhG-CSF. Endogenous G-CSF levels rose immediately after ABSCT, and an inverse correlation was found between the serum level of G-CSF and the absolute neutrophil count (r = -0.73, p < 0.01). The pre-dose level in patients receiving rhG-CSF rose gradually, reaching a maximum between days 3 and 6. The level gradually decreased as the neutrophil count began to rise, even through administration of the same dose of rhG-CSF continued. Pharmacokinetic data showed that the half-life of elimination of G-CSF (t1/2) exceeded 15 hours during severe neutropenia but decreased during the recovery of neutrophils. These observations suggest that neutrophils provide a negative feedback mechanism for clearing G-CSF from the circulation. Pre-dose levels of G-CSF in patients receiving 50 micrograms/m2 rhG-CSF reached 10 ng/mL, equivalent to the concentrations used in clonogenic assay in vitro to stimulate myeloid progenitor cells.
Assuntos
Fator Estimulador de Colônias de Granulócitos/sangue , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Transplante de Células-Tronco Hematopoéticas , Adolescente , Adulto , Feminino , Fator Estimulador de Colônias de Granulócitos/farmacocinética , Humanos , Japão , Cinética , Leucemia/terapia , Contagem de Leucócitos , Linfoma/terapia , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/terapia , Neoplasias/terapia , Neutrófilos , Proteínas Recombinantes/uso terapêutico , Transplante AutólogoRESUMO
CS-670, (+/-)-2-[4-(2-oxocyclohexylidenemethyl)phenyl]propionic acid, is a novel derivative of 2-arylpropionic acid non-steroidal anti-inflammatory drugs (profen NSAIDs). The major urinary metabolite of this drug from dogs was isolated and its chemical structure was determined by MS and NMR spectroscopy. The metabolite was identified as a taurine conjugate of the trans-OH form (trans-OH-taurine) which was first generated by stereoselective reduction of the double bond and the carbonyl function of the CS-670 molecule. The taurine conjugate was excreted in urine as the main metabolite, regardless of the optical configuration of CS-670 administered [2R)-enantiomer: 47.2% of the dose, (2S)-enantiomer: 70.9% of the dose]. The trans-OH-taurine was hydrolyzed by refluxing it in 6 N HCl without racemization. The released trans-OH was derivatized to diastereoamides with (+)-(R)-1-(1-naphthyl)ethylamine to examine the stereochemical properties of the 2-arylpropionic acid side chain. It was found that the configuration of the 2-carbon of the trans-OH-taurine was almost entirely (S). As the CoA thioesters are obligate intermediates for amino acid conjugation, the results suggest that the (2S)-enantiomer of the trans-OH metabolite serves as a substrate for canine acyl CoA ligase (EC 6.2.1.3) as well as the (2R)-enantiomer, but only the CoA thioester with a (2S)-configuration is a substrate for taurine N-acyl transferase. It is interesting to note that these results are not consistent with the chiral inversion mechanism by which the (2R)-enantiomers of profen NSAIDs are stereospecifically converted to CoA thioester intermediates.
Assuntos
Anti-Inflamatórios não Esteroides/metabolismo , Fenilpropionatos/metabolismo , Taurina/metabolismo , Animais , Anti-Inflamatórios não Esteroides/química , Biotransformação , Cromatografia Líquida de Alta Pressão , Cães , Espectroscopia de Ressonância Magnética , Masculino , Conformação Molecular , Fenilpropionatos/química , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Estereoisomerismo , Taurina/químicaRESUMO
Forty seven patients with hematological malignancies were treated with high doses of cytosine arabinoside (Ara C; 12 g/m2) and etoposide (VP-16), followed by recombinant human granulocyte colony-stimulating factor (rhG-CSF; 50 micrograms/m2). Peripheral blood progenitor cells (PBPC) were collected during rapid leukocyte recovery using a CS-3000 blood cell separator. A blood volume of 9 liters was processed in each apheresis, with 162 apheresis procedures performed. The mean numbers of mononuclear cells (MNC) and colony-forming unit granulocyte-macrophage (CFU-GM) harvested per apheresis were 4.4 x 10(8)/kg and 142.5 x 10(4)/kg, respectively. A sufficient number of CFU-GM for engraftment (> 30 x 10(4)/kg) could be harvested by a single apheresis in 35 of 47 patients (74%). Various factors that influence the collection of progenitor cells were analyzed by univariate and multivariate analyses. The number and duration of previous chemotherapy cycles were the most significant factors affecting CFU-GM yield. In patients with malignant lymphoma, age also had an influence in addition to these two factors. MNC harvested had an impact on CFU-GM yields by univariate analysis. These observations suggest that high-dose Ara C plus VP-16 followed by G-CSF is an effective regimen for harvesting PBPC. PBPC should be collected in the early stage of first-line chemotherapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/efeitos dos fármacos , Adolescente , Adulto , Idoso , Separação Celular , Citarabina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/administração & dosagemRESUMO
The glycoprotein allergen Cry j I from Japanese cedar (Cryptomeria japonica) pollen was treated with pepsin and glycopeptidase A to release asparagine-linked oligosaccharides. The reducing ends of the oligosaccharides were aminated with the fluorescent reagent 2-aminopyridine. The oligosaccharide derivatives were purified by gel permeation chromatography and reversed-phase HPLC. Their structures were determined by sequential exoglycosidase digestion and 500 MHz 1H-NMR spectroscopy. Four oligosaccharide structures, A, B, C, and D, were identified as the xylose-containing complex-type. They were present at a molar ratio of 8:1:6:1. By amino acid sequence analyses of the tryptic peptides, Asn-170 and Asn-333 of Cry j I were found to carry asparagine-linked oligosaccharides. [formula: see text]
Assuntos
Alérgenos/química , Oligossacarídeos/química , Proteínas de Plantas/química , Pólen/química , Sequência de Aminoácidos , Antígenos de Plantas , Asparagina , Configuração de Carboidratos , Sequência de Carboidratos , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Oligossacarídeos/isolamento & purificação , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Árvores , Tripsina , Xilose/análiseRESUMO
The structures of matlystatins, novel type IV collagenase inhibitors isolated from Actinomadura atramentaria, have been determined by a systematic application of homo- and heteronuclear 2D NMR and FAB-MS/MS techniques. Their structures were characterized by the presence of piperazic acid and hydroxamic acid moieties, structural motifs often seen in protease inhibitors.
Assuntos
Actinomycetales/metabolismo , Antibacterianos/química , Inibidores de Metaloproteinases de Matriz , Antibacterianos/farmacologia , Ácidos Hidroxâmicos/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Espectrometria de Massas de Bombardeamento Rápido de ÁtomosRESUMO
The solution conformation of rat cytokine-induced neutrophil chemoattractant (CINC/Gro), a small protein consisting of 72 amino acid residues with proinflammatory activities, and a member of the interleukin 8 family corresponding to a counterpart of human Gro, was investigated with homonuclear 2D and 3D NMR spectroscopy. At each phase of the structural analysis, the homonuclear 3D NOESY-HOHAHA and HOHAHA-NOESY spectra afforded valuable data, removing ambiguities intractable by conventional 2D NMR techniques. CINC/Gro exists as a dimer in solution and contains a triple stranded anti-parallel beta-sheet and C-terminal alpha-helix in the monomer structure, as observed in human IL-8, but non-trivial differences are also observed.