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1.
Adv Exp Med Biol ; 132: 519-25, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7191622

RESUMO

Ethanol was fed at a level of 35% of total caloric intake to mature male rats for intervals of one to 38 days. Mitochondrial content of cytochrome c oxidase per mg protein was maximally depressed, to 40% of control values, after 10 days feeding. After 15 days of ethanol feeding, leucine incorporation into total hepatocyte protein, as well as into total intracellular (subcellular fractions) or extracellular (secreted) proteins was substantially inhibited. At the level of total protein, alterations in isotope ratio as a consequence of ethanol feeding were only manifest in the secreted proteins. However, when component proteins of subcellular fractions were separated by gel electrophoresis, two specific early effects of ethanol feeding on protein synthesis by the endoplasmic reticulum could be detected. Aberrant isotope ratios established that synthesis of two entities, of 20000 and 50000 apparent molecular weight, was depressed after intervals of one and five days, respectively, feeding of 10% ethanol.


Assuntos
Alcoolismo/patologia , Fígado/citologia , Alcoolismo/metabolismo , Animais , Citocromos/metabolismo , Hemeproteínas/metabolismo , Humanos , Leucina/metabolismo , Fígado/metabolismo , Masculino , Mitocôndrias Hepáticas/enzimologia , Biossíntese de Proteínas , Ratos
2.
Blood ; 69(4): 1188-95, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3548845

RESUMO

Human platelet factor V has been isolated using either a monoclonal or polyclonal antibody directed against human plasma factor V. The largest peptide observed upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of purified human platelet factor V comigrates with purified human plasma factor V. However, a significant portion of the isolated protein is represented by peptides of lower apparent molecular weight (Mr). These lower Mr species that copurify with platelet factor V have been shown to be platelet factor V components by their immunological cross-reactivity with monoclonal and polyclonal antibodies to purified human plasma factor V. Platelets isolated from whole blood drawn directly into inhibitors to prevent proteolysis and platelet activation demonstrate the pattern of fragmented platelet factor V. The components of purified platelet factor V demonstrate apparent Mr ranging between 115 K and 330 K and are detectably different from the intermediates and end products observed during the thrombin cleavage of single-chain plasma factor V. Upon treatment with thrombin the platelet factor V components are cleaved and the end products are indistinguishable from those obtained upon thrombin activation of plasma factor V to plasma factor Va. Examination of the components by immunoblotting demonstrates that some of the cleavages which have occurred in the platelet factor V molecule are within the 150-K activation peptide. Bioassay indicates that platelet factor V exists as a procofactor and cleavage by thrombin yields the active cofactor, platelet factor Va. These data suggest that human platelet factor V is stored in the platelet as a partially fragmented procofactor that can be activated by thrombin to yield human platelet factor Va, the active cofactor in the human prothrombinase complex.


Assuntos
Fatores de Coagulação Sanguínea/isolamento & purificação , Plaquetas/análise , Fator V/análise , Coagulação Sanguínea , Humanos , Técnicas Imunológicas , Peso Molecular , Trombina/metabolismo
3.
Exp Aging Res ; 5(6): 487-96, 1979 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-527618

RESUMO

Experiments involving simultaneous comparisons of cells from two animals establish an age-dependent decline in protein synthesis. Specific radioactivities of fractions from cells of aged animals (20+ months) are depressed 60% to 80% versus those from younger animals (2 to 14 months). Isotope ratio patterns derived by PAGE indicate that formation of a 20000 MW polypeptide of cytoribosomal origin is even more strongly and specifically depressed.


Assuntos
Envelhecimento , Fígado/metabolismo , Biossíntese de Proteínas , Animais , Leucina/metabolismo , Fígado/análise , Fígado/ultraestrutura , Masculino , Biossíntese Peptídica , Ratos , Frações Subcelulares/metabolismo
4.
Anal Biochem ; 142(2): 373-7, 1984 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-6397075

RESUMO

That the macroporous anion-exchange resin AG MP-1 can be used with HPLC equipment and common aqueous buffers for the chromatography of proteins is shown. The utility of this system is illustrated by the partial purification and complete resolution of the three protein synthesis elongation factors from each other, starting with a crude extract of Escherichia coli. The factors were purified 10- to 30-fold in a yield of 50 to 90% with a single 60-min chromatographic program of increasing NaCl concentration. Other proteins from various biological sources were purified with similar results. Thus, it appears that AG MP-1 is useful, at least in some applications, for the rapid, reproducible, and economical purification of proteins using HPLC equipment.


Assuntos
Resinas de Troca Aniônica , Resinas de Troca Iônica , Proteínas/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia por Troca Iônica/instrumentação , Cromatografia por Troca Iônica/métodos , Escherichia coli/análise , Fígado/enzimologia , Fatores de Alongamento de Peptídeos/isolamento & purificação , Ratos , Resinas Sintéticas , Saccharomyces cerevisiae/análise
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