RESUMEN
The acid-soluble, highly cross-linked aorta collagen, of which about 30% can be converted into a soluble form by alkali treatment, followed by extraction with aetic acid, was obtained predominantly in the form of monomeric, helical molecules, as indicated by the value for the intrinsic viscosity and its behaviour in sodium dodecylsulphate disc electrophoresis. Apart from decreased values for tyrosine (0.26%), arginine (4.4%) and aspartic acid (3.9%), the amino acid composition of the aorta collagen fraction was similar to that of the acid-soluble calf skin collagen. This finding, together with the cyanogen bromide peptide pattern, shows that the collagen extracted from the artery is predominantly type I. Treatment with alkali probably shortens the alpha1-CB6-peptide by about 45 amino acids. The collagen extracted from artery was compared with acid soluble skin collagen by sodium dodecylsulphate polyacrylamide electrophoresis. The arterial collagen showed a marked increase in the rations alpha1 to alpha2 (4:1), alpha to beta (3:1) and beta11 to beta12 (2.5:1). Compared with acid soluble skin collagen, the aorta collagen contained twice as much galactose and glucose (13.5 and 9.6 nmol/mg protein respectively), which are bound to hydroxylysine. 50% of the hydroxylysine residues are unsubstituted, 15% are present as galactosyl hydroxylysine, and 35% as glucosyl-galactosyl hydroxylysine. On the basis of its reported properties, arterial collagen obtained by the method of Fujii appears to be a suitable substrate for the study of the enzymic synthesis and enzymic degradation of hydroxylysine glycosides of native arterial collagen.
Asunto(s)
Aorta/análisis , Colágeno/aislamiento & purificación , Aminoácidos/análisis , Animales , Bovinos , Densitometría , Electroforesis Discontinua , Galactosa/análisis , Glucosa/análisis , Hidrólisis , Hidroxilisina/aislamiento & purificación , Conformación Proteica , Piel/análisis , Solubilidad , ViscosidadRESUMEN
Several peptides were isolated from tryptic digests of insoluble calf aorta matrix by chromatography. Reductive pyridylethylation of a tryptic 15 kDa pool released fragments deriving from the C-terminus of type III collagen. A 50-residue peptide Tc(III) was shown by sequence analysis to be the C-terminal peptide from the alpha 1(III)-chain, containing a helical and non-helical region of equal sizes. The peptide was further digested with collagenase to give Colc(III), comprising the complete C-terminal non-helical region of alpha 1(III) including a hydroxylysine in position 16c. The peptide Tc(III) x TN(III) was isolated, demonstrating covalent cross-linking between the C-terminal non-helical region of one type III molecule and the N-terminal helical cross-linking region of another. Its digestion with cyanogen bromide yielded the small fragments alpha 1(III)CB3B* and alpha 1(III)CB3C, confirming TN(III) as an N-terminal helical crosslink site. Sequence analysis of both Tc(III) x TN(III) and its collagenase-derived cross-linked peptide Colc(III) x TN(III) established the 4D-staggered alignment of adjacent collagen III molecules. The cross-link structure of both peptides was mainly dihydroxylysinonorleucine with a small amount of hydroxylysinonorleucine, indicating that the lysine residues involved in formation of the cross-links are both hydroxylated. No pyridinoline or histidinohydroxylysinonorleucine cross-links were found within the non-reduced C-telopeptide region of type III collagen.
Asunto(s)
Colágeno/química , Secuencia de Aminoácidos , Animales , Aorta/química , Secuencia de Bases , Borohidruros , Bovinos , Cromatografía en Gel , Reactivos de Enlaces Cruzados , Disulfuros , Sustancias Macromoleculares , Modelos Estructurales , Datos de Secuencia Molecular , Músculo Liso Vascular/química , Fragmentos de Péptidos/química , Fragmentos de Péptidos/aislamiento & purificación , Estructura Secundaria de Proteína , TripsinaRESUMEN
The glucosyltransferase (UDP-glucose galactosylhydroxylsine collagen glucosyltransferase, EC 2.4.1.?.) was purified 50-fold from calf arterial tissue by ammonium sulfate precipitation, gel filtration and electrofocusing. The purified enzyme has a molecular weight of 72 000 and a requirement for Mn2. It resolves into two activity peaks when submitted to electrofocusing (isoelectric point at pH 4.2 and 8.1) or disc electrophoresis and exhibits a double pH optimum (pH 8.3 and 9.9). The enzyme was found to transfer glucose from UDP-glucose to the denatured forms of citrate-soluble calf skin collagen (I), the alphal chain (II) and the beta12 component (III) derived from it, and of an acetic-acid-souble collagen preparation (IV) obtained from alkali-treated calf arterial tissue. The Km values for the substrates were 1.67 X 10(-4) (I), 6.3 X 10(-4) (II), 3.3 X 10(-4) (III) and 2.8 X 10(-4) mol/l (IV), indicating that the enzyme has the greatest affinity for the calf skin collagen. The glucose transferred to hydroxylysine-linked galactose residues may be released subsequently by the action of a specific alpha-glucosidase purified from bovine spleen. The results support the assumtion that the glucosylation step in the course of the (pro-)-collagen biosynthesis depends on special structural features of the substrate and may be controlled by a specific alpha-glucosidase.
Asunto(s)
Aorta Torácica/enzimología , Glucosiltransferasas/aislamiento & purificación , Animales , Bovinos , Colágeno , Galactosa , Glucosiltransferasas/metabolismo , Concentración de Iones de Hidrógeno , Hidroxilisina , Cinética , Uridina Difosfato GlucosaRESUMEN
The occupational anamneses of 400 patients of the Martin-Luther-Universität with the Diagnoses idiopathic hip-head necrosis, melanoma, basaloma as well as larynx carcinoma, salivary tumor, and neoplasm in pharynx and oral cavity are analysed. The essential results of the investigation in regard to the characteristics sex, age, smoking, habitude, tumor in the family anamnesis, and occupational exposure are presented.
Asunto(s)
Carcinoma Basocelular/etiología , Necrosis de la Cabeza Femoral/etiología , Neoplasias de Cabeza y Cuello/etiología , Melanoma/etiología , Enfermedades Profesionales/etiología , Neoplasias Cutáneas/etiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
A radioactive peptide has been isolated from cyanogen bromide digests of sodium boro[3H]-hydride-reduced collagen from rabbit bone, tendon and skin. It was identified as a crosslinked peptide linking the short C-terminal cyanogen bromide peptide alpha1-CB6B (17 amino acid residues) to alpha1-CB5 (37 residues) from the helical part of the chain of an adjacent molecule. Both peptides could be separated after cleaving the crosslink with periodate. Thus the crosslinked peptide alpha1-CB5 X alpha1-CB6B originates from an intermolecular crosslink between quarter-staggered molecules within collagen fibrils previously assigned as 'head-to-tail' link. The chemical nature of the reduced crosslinking component was identified and was shown to differ between peptides derived from different tissues: alpha1-CB6B X alpha1 CB5 from bone contains hydroxylysinohydroxynorleucine [o5Lys(o5omegaNle)] whereas the skin peptide contains hydroxylysinonorleucine [o5Lys(omegaNle)]. The peptide derived from tendon contains both components. The relation of o5Lys(omegaNle) to o5Lys(o5omegaNle) in the peptides corresponds to that of the original tissue. On the other hand, histidino-hydroxymerodesmosine which is a major reduced cross-linking component in skin and tendon, is completely absent in the isolated peptides. The crosslinking component in the skin peptide is completely glycosylated, mainly by glucosylgalactosyl residues and to a smaller extent by galactosyl residues. o5Lys(o5omegaNle) from the bone peptide is only partly glycosylated, containing equal amounts of the disaccharide and monosaccharide. Only slight glycosylation was found in the tendon peptide.
Asunto(s)
Colágeno , Secuencia de Aminoácidos , Aminoácidos/análisis , Animales , Huesos , Bromuro de Cianógeno , Sustancias Macromoleculares , Peso Molecular , Especificidad de Órganos , Fragmentos de Péptidos/aislamiento & purificación , Unión Proteica , Conejos , Piel , Solubilidad , TendonesRESUMEN
Two models of pneumonia--the experimental E. coli-pleuropneumonia and "intrapulmonary" E. coli-pneumonia--were employed in these studies. Only fosfomycin was effective in both models even at the low dosage of 100 mg/kg/d. The comparative drugs cefotaxime and cefoxitin, however, were not able to reduce the bacteria in both lungs even at very high dosages of 900 mg/kg and 300 mg/kg per day respectively over 6 days.
Asunto(s)
Antibacterianos/uso terapéutico , Cefoxitina/uso terapéutico , Cefalosporinas/uso terapéutico , Infecciones por Escherichia coli , Fosfomicina/uso terapéutico , Pleuroneumonía/tratamiento farmacológico , Animales , Cefotaxima , Relación Dosis-Respuesta a Droga , Femenino , Cinética , RatasRESUMEN
Escherichia coli 536 (O6:K15:H31), which was isolated from a case of urinary tract infection, determines high nephropathogenicity in a rat pyelonephritis system as measured by renal bacterial counts 7 days after infection. The loss of S fimbrial adhesin formation (Sfa-) (mannose-resistant hemagglutination [Mrh-] and fimbria production [Fim-]), serum resistance (Sre-), and hemolysin production (Hly-) in the mutant 536-21 led to a dramatic reduction of bacterial counts from almost 10(5) to only 40 cells per g of kidney. The reintroduction of the cloned S fimbrial adhesin determinant (sfa) increases the virulence of the avirulent mutant strain by a factor of 20; almost the same effect was observed after restoration of serum resistance by integration of an sfa+ recombinant cosmid into the chromosome. Additional reintroduction of the Hly+ phenotype by transformation of two hly determinants increased the virulence of the strains. Hemolysin production determined increased renal elimination of leukocytes and erythrocytes. Thus all three determinants investigated, S fimbriae, serum resistance, and hemolysin, contribute to the multifactorial phenomenon of E. coli nephropathogenicity.
Asunto(s)
Escherichia coli/patogenicidad , Hemaglutininas/genética , Proteínas Hemolisinas/genética , Pielonefritis/microbiología , Adhesinas de Escherichia coli , Animales , Adhesión Bacteriana , Proteínas Bacterianas/genética , Actividad Bactericida de la Sangre , Clonación Molecular , Modelos Animales de Enfermedad , Escherichia coli/genética , Fimbrias Bacterianas , RatasRESUMEN
A collagenous trimeric cross-linked peptide has been isolated from the insoluble matrix of calf aorta, using trypsin solubilisation, and purified by gel filtration, cation-exchange chromatography and reversed-phase HPLC. Molecular mass and amino acid composition indicated that the C-terminal, non-helical region of type I collagen in its dimer form, designated as [ColC(I)]2, is cross-linked to a tryptic peptide TN(I) from the N-terminal helical cross-link region of an adjacent type I molecule, forming the cross-linked peptide [ColC(I)]2 X TN(I). Amino acid sequence analysis of the peptide yielded a series of sequences corresponding to the cross-linking domains ColC(I) and TN(I) and furnished the first direct chemical evidence for the 4D staggered arrangement of type I molecules within native fibers. The trifunctional cross-linking amino acid pyridinoline was shown to occur in the peptide, confirming the peptides three-chain structure. Pyridinoline was isolated from the cross-linked peptide by preparative amino acid analysis and reversed-phase HPLC and identified by its ultraviolet absorption spectra, its fluorescence excitation and emission spectra and, for the first time, its time-of-flight secondary ion-mass spectrum. The high sensitivity of the latter method, exceeding that of fast-atom-bombardment mass spectroscopy by three orders of magnitude, allowed detection of pyridinoline in the picomole range. The occurrence of pyridinoline in non-stoichiometric amounts, the presence of hydroxylysine in hydrolysates of all cross-linked peptides and the finding that hydrolysates also contained an unidentified component indicated that there is at least one cross-link form that is different from pyridinoline and is hydrolysable.
Asunto(s)
Aminoácidos/aislamiento & purificación , Aorta/análisis , Colágeno/aislamiento & purificación , Péptidos/aislamiento & purificación , Secuencia de Aminoácidos , Aminoácidos/análisis , Animales , Bovinos , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Colágeno Tipo I , Espectrometría de Masas/métodos , Solubilidad , Espectrometría de Fluorescencia , Espectrofotometría UltravioletaRESUMEN
Fetal calf skin was solubilized by limited pepsin digestion and type III collagen separated from type I collagen by fractional salt precipitations. Cleavage of the type III collagen with CNBr gave rise to ten peptides, which were isolated by molecular sieve and ion exchange chromatography. The peptides were characterized by determination of their molecular weights and amino acid compositions. Together they account for all the amino acids and total molecular weight of the alpha1 (III) chain. Six of the peptides contain more hydroxyproline than proline residues. The two cysteinyl residues of the alpha1 (III) chain which provide sites for interchain disulfide bonding were localized in the C-terminal CNBr peptide. In addition to the ten CNBr peptides, three double peptides were isolated which still contained one methionine residue. About 0.1 residue Gal-Hyl monosaccharide and 0.8 Glc-Gal-Hyl residue disaccharide were found per alpha1 (III) chain. Almost all hydroxylysine-bound carbohydrate was located on peptide 7.
Asunto(s)
Colágeno/análisis , Péptidos/análisis , Alquilación , Aminoácidos/análisis , Animales , Carbohidratos/análisis , Bovinos , Bromuro de Cianógeno , Peso Molecular , Oxidación-Reducción , Pepsina A , Péptidos/aislamiento & purificaciónRESUMEN
The therapeutic effectiveness of (6R,7R)-7-(2-[3,5-dichloro-4-oxo-1(4H)-pyridyl]-acetamido)-3-([(5-methyl-1,3,4-thiadiazol-2-yl)-thio]methyl)-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid (cefazedone, Refosporen), cephazolin, cephacetrile and cephalothin was compared in the test model of estradiol-induced E. coli pyelonephritis in the rat. Cefazedone and cephazolin were similar in effect. The relations between results of treatment and microbiological and pharmacokinetic characteristics of the cephalosporins tested are discussed.
Asunto(s)
Cefalosporinas/uso terapéutico , Infecciones por Escherichia coli/tratamiento farmacológico , Pielonefritis/tratamiento farmacológico , Animales , Cefalosporinas/metabolismo , Femenino , Cinética , Pielonefritis/etiología , RatasRESUMEN
By transurethral instillation of a suspension of a serum resistant E. coli strain (serotype O25:19:12), chronic pyelonephritis is induced in rats, if systemic and local defense mechanisms are impaired by estradiol application. Without hormonal treatment a similar infection can be achieved with a more virulent E. coli strain (serotype O2:1:4). Due to the chronic course of the renal infection in either model, beginning of therapy may be delayed (e.g., 10 days after infection) thus imposing difficult therapeutic conditions on the efficacy of antibiotics to be tested. Evaluation of antibiotics in both models produced differential therapeutic results. In spite of equal MIC's for the applied E. coli strains, gentamicin and particularly cefazolin treatment was less effective in the estradiol treated rats than in those without hormone application. Cefuroxime therapy produced favourable results in either model. The different therapeutic efficacy in both models is to be explained by differences in host resistance to infection. It is suggested that by simultaneans testing of antibiotics in either model, it will be possible to estimate to what extent the therapeutic efficacy of antibiotics depends on the support of intact host defense mechanisms.
Asunto(s)
Antibacterianos/uso terapéutico , Escherichia coli/efectos de los fármacos , Pielonefritis/tratamiento farmacológico , Animales , Cefazolina/uso terapéutico , Enfermedad Crónica , Estradiol , Femenino , Gentamicinas/uso terapéutico , Riñón/microbiología , Pielonefritis/etiología , RatasRESUMEN
We studied hemagglutinating and adherence properties in Staphylococcus saprophyticus isolates originating from symptomatic urinary tract infections. 12/13 (92%) of strains adhered to Hep cells and 11/13 (85%) were able to agglutinate sheep erythrocytes. Adherence properties differed markedly between strains (P less than 0.0001). Two strains, one hemagglutinating and adherent and one negative for both properties were chosen for experimental urinary tract infections. Results indicate that presence of the hemagglutinin favours colonization of kidney tissue.
Asunto(s)
Infecciones Estafilocócicas/microbiología , Staphylococcus/fisiología , Infecciones Urinarias/microbiología , Animales , Adhesión Bacteriana , Femenino , Hemaglutinación , Humanos , Ratas , Ratas Endogámicas , Staphylococcus/aislamiento & purificación , Staphylococcus/patogenicidad , VirulenciaRESUMEN
Infectivity titers were determined for eight Chlamydia pneumoniae strains simultaneously grown in serum-free and serum-supplemented cell culture media. Use of serum-free medium resulted in a 10- to 50-fold increase in the susceptibility of HL cells to chlamydial infection. Comparative primary isolation of a wild-type strain also produced higher inclusion counts in a serum-free environment. Serum-free cultivation is recommended to increase the efficiency of C. pneumoniae isolation from clinical material and to permit elementary body purification without interference caused by serum components.
Asunto(s)
Chlamydophila pneumoniae/crecimiento & desarrollo , Chlamydophila pneumoniae/aislamiento & purificación , Medio de Cultivo Libre de Suero , HumanosRESUMEN
A well-characterized three-chain peptide [(Col1)2 X T9] from human type III collagen was a rich source of Ehrlich chromogen. The corresponding two-chain peptide [(Col1)2] was not, implying that the Ehrlich chromogen is a trifunctional cross-link. (Col1)2 X T9 also contained pyridinoline, which is not an Ehrlich chromogen. The 7S domain of type IV collagen also contained an Ehrlich chromogen.
Asunto(s)
Benzaldehídos , Colágeno , Péptidos/análisis , Aminoácidos/análisis , Compuestos Cromogénicos , Humanos , Indicadores y Reactivos , Conformación ProteicaRESUMEN
The case of acute purulent group B streptococcal myocarditis in a 29-year-old Turk is described, no similar case having previously been published. He fell ill suddenly with gastro-intestinal symptoms, high fever and pain in arms and legs. The ECG had low voltage in the limb leads and signs of a large acute myocardial infarct. The sedimentation rate was slightly raised, an initial leukopenia was followed by leukocytosis and high enzyme activity. He died in cardiogenic shock on the third day of illness. The post-mortem examination revealed acute purulent myocarditis, and numerous group B streptococci (Strept. agalactiae) were found in the myocardium.
Asunto(s)
Miocarditis/diagnóstico , Infecciones Estreptocócicas/diagnóstico , Adulto , Autopsia , Electrocardiografía , Humanos , Masculino , Miocarditis/complicaciones , Miocarditis/patología , Choque Cardiogénico/complicaciones , Infecciones Estreptocócicas/complicaciones , Infecciones Estreptocócicas/patología , Streptococcus agalactiaeRESUMEN
The amino terminal 227 amino acid residues of the alpha 1(III) chain contain four CNBr peptides: alpha 1(III)CB3A (79 residues), CB3B, CB3C (6 residues each), CB7 (37 residues) and CB6 (99 residues). Fragmentation of the CNBr peptides was carried out using trypsin, chymotrypsin and the protease from Staphylococcus aureus V8. The fragments obtained were isolated by a combination of molecular sieve and ion exchange chromatography. The sequence analysis was performed according to the automated Edman degradation procedure.
Asunto(s)
Colágeno , Piel/análisis , Secuencia de Aminoácidos , Animales , Bovinos , Quimotripsina , Sustancias Macromoleculares , Fragmentos de Péptidos/análisis , Péptido Hidrolasas , Staphylococcus aureus/enzimología , TripsinaRESUMEN
Solid-phase synthesis of triple-helical peptides, including native collagen III sequences, was started with a trimeric branch, based upon the lysine dipeptide [Fields, C. G., Mickelson, D. J., Drake, S. L., McCarthy, J. B., and Fields, G. B. (1993) J. Biol. Chem. 268, 14153-14160]. Branch synthesis was modified, using TentaGel R as resin, p-hydroxybenzyl alcohol (HMP) as linker, Dde as N(epsilon)-protective group, and HATU/HOAT as coupling reagent. Three homotrimeric sequences, each containing the Gly 606-Gly 618 portion of human type III collagen, were added to the amino functions of the branch. The final incorporation of GlyProHyp triplets, stabilizing the collagen III triple helix, was performed by using protected GlyProHyp tripeptides, each containing tert-butylated hydroxyproline [P(tBu)] instead of hydroxyproline (P). Among the protected tripeptides FmocP(tBu)PG, FmocPP(tBu)G, and FmocGPP(tBu), prepared manually on a chlorotrityl resin, incorporation of FmocPP(tBu)Gly was best suited for synthesis of large and stable peptides, such as PPG(8), containing 8 (PPG)(3) trimers (115 residues, 10 610 Da). The structures of five peptides, differing from each other by the type and number of the triplets incorporated, were verified by MALDI-TOF-MS. Their conformations and thermodynamic data were studied by circular dichroism and differential scanning calorimetry. Except for PPG(8), containing 8 (PPG)(3) trimers with hydroxyproline in the X position and adopting a polyproline II structure, all peptides were triple-helical in 0.1 M acetic acid and their thermal stabilities ranged from t(1/2) = 39. 4 to t(1/2) = 62.5 degrees C, depending on the identity and number of the triplets used. Similar values of the van't Hoff enthalpy, DeltaH(vH), derived from melting curves, and the calorimetric enthalpy, DeltaH(cal), obtained from heat capacity curves, indicate a cooperative ratio of CR = DeltaH(vH)/DeltaH(cal) = 1, establishing a two-state process for unfolding of THP(III) peptides. The independence of the transition temperatures t(1/2) on peptide concentration as well as equilibrium centrifugation data indicate monomolecular dimer(f) to dimer(u) (F(2) <--> U(2)) transitions and, in addition, bimolecular dimer(f) to monomer(u) transitions (F(2) <--> 2U). The dominance of the concentration-independent monomolecular reaction over the concentration-dependent bimolecular reaction makes thermal unfolding of THP(III) peptides appear to be monomolecular. If one designates the molecularity described by the term pseudomonomolecular, unfolding of the dimeric peptides PPG(6-8) follows a two-state, pseudomonomolecular reaction.