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1.
Mov Disord ; 16(4): 705-7, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11481695

RESUMO

Oxidative stress reactions may contribute to the pathogenesis of Parkinson's disease (PD). The superoxide dismutases potentially play significant roles in PD by detoxifying superoxide radical. We developed genomic DNA and cDNA-based sequencing assays to identify genetic variants in the copper/zinc superoxide dismutase (SOD1) and manganese superoxide dismutase (SOD2) genes. No genetic variants were detected in the gene encoding SOD1 in DNA from 45 idiopathic PD cases and 49 controls from a population-based case-control study. However, we identified a previously described polymorphism of the mitochondrial targeting sequence consisting of a C47T in exon 2 of SOD2, which results in an alanine to valine substitution. We analyzed this SOD2 variant in DNA from 155 cases and 231 controls from the same study, using an allele-specific fluorogenic 5' nuclease assay, and found no differences in the distributions of allelic frequencies. These results indicate that SOD gene variants do not contribute to PD pathogenesis.


Assuntos
Doença de Parkinson/genética , Polimorfismo Genético/genética , Superóxido Dismutase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Frequência do Gene/genética , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/fisiologia , Doença de Parkinson/enzimologia , Fatores de Risco
2.
J Chromatogr ; 638(2): 311-8, 1993 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-8392515

RESUMO

In peptide analysis, capillary zone electrophoresis (CZE) gives complementary information to that obtained using high-performance liquid chromatography and capillary isotachophoresis. However, a prerequisite for the implementation of CZE for routine quality control purposes is a simple strategy quickly leading to an adequate separation system. A general approach towards the set-up of such systems is presented. A broad range of peptides were used as representative models, viz., adrenocorticotropic hormone (ACTH), the modified ACTH fragment Org 2766, endorphins, cholecystokinin and fragments thereof. In general, the pH and the concentration of the applied electrophoresis buffers are the most important parameters to be considered in the CZE of pharmaceutical peptides.


Assuntos
Peptídeos/análise , Hormônio Adrenocorticotrópico/análogos & derivados , Hormônio Adrenocorticotrópico/análise , Sequência de Aminoácidos , Soluções Tampão , Colecistocinina/análise , Eletroforese , Endorfinas/análise , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Fragmentos de Peptídeos/análise , Controle de Qualidade
3.
J Chromatogr ; 545(2): 379-89, 1991 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-1653256

RESUMO

Capillary electrophoresis can be used successfully to analyse small peptides to give additional information to that obtained using high-performance liquid chromatography (HPLC). The separation of a modified adrenocorticotropic hormone (4-9) fragment (Org 2766) and several of its fragments was investigated using capillary zone electrophoresis. Prediction of migration in aqueous systems using pKa-related data and the migration behaviour using sodium dodecyl sulphate in the buffer are discussed, as is the choice of buffer systems. The electrophoretic patterns are compared with the HPLC separation.


Assuntos
Hormônio Adrenocorticotrópico/isolamento & purificação , Eletroforese/métodos , Fragmentos de Peptídeos/isolamento & purificação , Hormônio Adrenocorticotrópico/análogos & derivados , Hormônio Adrenocorticotrópico/química , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Fragmentos de Peptídeos/química
4.
Int J Pept Protein Res ; 36(2): 167-72, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1980269

RESUMO

The hexapeptide dimer (H-Hcy-Glu-His-Phe-D-Lys-Phe-OH)2 was synthesized using solution methods and characterized. Its conversion into H-Met(O2)-Glu-His-Phe-D-Lys-Phe-OH, Org 2766, was studied on a small scale in as short a time as possible; reduction of the disulfide bond using Na/NH3, reaction with CH3I, oxidation with H2O2 and catalyst and purification by HPLC were carried out starting with 2 mg of the dimer in a total preparation time of approximately 22 min, starting with the addition of CH3I. The preparation of the 11C-labelled analogue was carried out by methylation with 11CH3I. Restrictions imposed by working with carbon-11 will be discussed.


Assuntos
Hormônio Adrenocorticotrópico/análogos & derivados , Ansiolíticos/síntese química , Fragmentos de Peptídeos/síntese química , Hormônio Adrenocorticotrópico/síntese química , Sequência de Aminoácidos , Dados de Sequência Molecular , Traçadores Radioativos
5.
J Chromatogr ; 470(1): 171-83, 1989 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-2544620

RESUMO

Reversed-phase high-performance liquid chromatography is a valuable analytical technique to support the synthesis, isolation and purification of peptides, as is illustrated by some critical separations. In addition to this technique, capillary isotachophoresis can give useful information on the purity determination of peptides and on the presence of ionic compounds of a non-peptidic nature. With regard to the latter aspect, isotachophoresis proved to be a suitable technique as a check on the effective removal of salts after preparative high-performance liquid chromatography.


Assuntos
Peptídeos/análise , Hormônio Adrenocorticotrópico/análogos & derivados , Hormônio Adrenocorticotrópico/análise , Animais , Bovinos , Colecistocinina/análise , Cromatografia Líquida de Alta Pressão , Eletroforese/métodos , Humanos , Insulina/análise , Fragmentos de Peptídeos/análise , Espectrofotometria Ultravioleta , Suínos , Vasopressinas/análise , beta-Endorfina/análise
6.
Pharm Weekbl Sci ; 9(3): 172-8, 1987 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-3302930

RESUMO

Partially purified insulin preparations of bovine and porcine origin, were subjected to gamma-irradiation with doses ranging from 1.0 up to 25 kGy (0.1-2.5 Mrad) at 0 degrees C or ambient temperature. The susceptibility of insulin to the irradiation was determined by chromatography, electrophoresis and assay of the biological activity. The sterilizing effect of the gamma-irradiation was investigated for Bacillus pumilus as well as for artificial mixtures of lactose and several bacilli. It is concluded that the sterilizing dose for the investigated insulins was greater than or equal to 2.2 kGy. At doses up to 25 kGy at 0 degree C no specific radiolytic products were detectable, whereas the biological activity was fully retained. The content of dimers and the content of related peptides appeared to increase gradually with the irradiation dose absorbed. No effects of long-term storage could be demonstrated on biological and chemical properties of insulin after 2.2, 4.5 and 7.5 kGy.


Assuntos
Insulina/efeitos da radiação , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Raios gama , Técnicas In Vitro , Doses de Radiação , Esterilização
7.
J Steroid Biochem ; 22(6): 831-6, 1985 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-4021486

RESUMO

Previous in vitro binding studies with androgen receptors in rat seminal vesicles (Toth M. and Zakar T., J. steroid Biochem. 17 (1982) 653-660) have shown that the difference in the effects of nandrolone (N) and testosterone (T) is caused by the fact that 5 alpha-reduction increases the affinity of T and decreases the affinity of N. We confirmed this result using androgen receptors in rat prostate and intact human MCF-7 cells. We also analysed the receptor binding properties of N, T, dihydronandrolone (DHN) and dihydrotestosterone (DHT) in vivo following a combined 2-h infusion of a physiological dose of [3H]T and the same dose of [3H]N in castrated male rats, which permitted a direct comparison of the accumulation of [3H]N, [3H]T, [3H]DHN and [3H]DHT in different sub-cellular fractions of various tissues. There was a considerable accumulation of radioactivity in the liver, but no retention of active compounds. In the prostate there was a preferential retention of [3H]DHT over [3H] DHN in the receptor fractions whereas in thymus, spleen and muscular tissues [3H]N and [3H]T were retained in equal amounts. The kidney showed a preferential retention of [3H]N over [3H]T. The present results explain the relatively strong effect of nandrolone compared to that of testosterone on target tissues devoid of 5 alpha-reductase activity (e.g. muscular tissue) compared to its relatively weak effect on tissues with a relatively high 5 alpha-reductase content (e.g. prostate).


Assuntos
Nandrolona/metabolismo , Próstata/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Esteroides/metabolismo , Testosterona/metabolismo , Animais , Castração , Linhagem Celular , Di-Hidrotestosterona/metabolismo , Humanos , Rim/metabolismo , Masculino , Nandrolona/análogos & derivados , Nandrolona/farmacologia , Ratos , Ratos Endogâmicos , Receptores Androgênicos/efeitos dos fármacos , Testosterona/farmacologia , Distribuição Tecidual
8.
J Chromatogr Sci ; 22(6): 234-8, 1984 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6086687

RESUMO

The application of reversed-phase high performance liquid chromatography in peptide chemistry is illustrated. Its use is described for separation of closely related endorphins, as an optical purity criterion, for rapid determination of the species of origin of insulin preparations, and finally for analysis of small, basic (hydrophilic) peptides.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Peptídeos/isolamento & purificação , Hormônio Adrenocorticotrópico/análogos & derivados , Hormônio Adrenocorticotrópico/isolamento & purificação , Animais , Bovinos , Fenômenos Químicos , Físico-Química , Cromatografia Líquida de Alta Pressão/instrumentação , Endorfinas/isolamento & purificação , Humanos , Insulina/isolamento & purificação , Fragmentos de Peptídeos/isolamento & purificação , Ratos , Suínos , beta-Endorfina
9.
Int J Pept Protein Res ; 17(2): 256-62, 1981 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7228500

RESUMO

The application of analytical capillary, carrier-free isotachophoresis as a rapid method (approx. 10-15 min per run) for the simultaneous determination of anions present in peptides (as counterion, contaminating ion or peptide anion) is described. Only small amounts of material, approx. 0.1-1.0 mg, are necessary to obtain information on the nature of the anion (qualitative) and of the amount of anion present (quantitative aspect).


Assuntos
Eletroforese/métodos , Peptídeos/análise , Ânions , Ação Capilar
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