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1.
J Therm Biol ; 116: 103674, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37542839

RESUMO

The aim of the present study was to evaluate the effects of ambient temperature and coriander seeds supplementation on growth performance and carcass characteristics of Koekoek chickens. In the experiment, chickens were exposed to two temperature rooms with a heated room of 32 ± 1.2 °C from 11:00 to16:00 h and a normal room temperature with an average maximum and minimum of 23.8 ± 3 °C and 16.6 ± 1.6 °C, respectively, and a relative humidity between 34.5 ± 4 and 44.8 ± 3%. The chickens were supplemented with 0, 5, and 10 g/kg of coriander seed powder. The results showed that the group of Koekoek chickens placed in a heated room had significantly lower (P < 0.05) feed intake and weight gain and significantly higher (P < 0.05) feed conversion ratio than the groups placed at normal room temperature. Water intake was 1.8% higher in the groups placed in a heated room than those placed at normal room temperature. Supplementation with coriander seed powder enhanced growth performance and carcass traits. The carcass weight and breast percentage were higher (P < 0.05) in the groups that received 10 g/kg coriander seed powder. The growth performance of the Koekoek groups supplemented with 10 g/kg coriander seed powder in a heated room also improved significantly compared to groups in a heated room without supplementation. This suggests that the supplementation of coriander seed improves performance, and has a positive potential effect in alleviating the negative effects of heat stress on growth performance of chickens.


Assuntos
Coriandrum , Dieta , Animais , Dieta/veterinária , Galinhas , Pós , Temperatura , Suplementos Nutricionais/análise , Ração Animal/análise
2.
Front Public Health ; 8: 517964, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194938

RESUMO

In African countries, antimicrobial resistance (AMR) issue remains pertinent. Despite this, little efforts have been made to assess the future veterinary prescribers on their knowledge, attitudes and practices (KAP) related to antimicrobial usage. This multi-country survey attempts to explore the KAP of future veterinarians on stewardship of antimicrobial and identify knowledge gaps. Eight veterinary schools participated from Nigeria, Sudan and South Africa. Data regarding perceptions and knowledge were analyzed using Chi-square χ2 test, Spearman's (Rho) Rank order correlation and factor analysis using principal component factoring extraction method. Fifty-two percent of the study participants were final year veterinary students, respectively, and majority (77.2%) had no previous knowledge of biomedical sciences. Majority age were 22-27 years (24.7 ± 2.8) 79% and multiple career fields post-graduation were preferred. Overall, poor perceptions and knowledge of antimicrobial stewardship were observed with variations among countries and only 36.3% (n = 123) of the students were confident in their ability to choose the ideal antimicrobial agents for a specific patient/group of animals. The majority of the final year students were confident of their knowledge regarding AMR (68%), making of Gram staining (69.2%) and in choosing the most ideal route for administering a specific antimicrobial (74.7%). The final year students had significantly (p < 0.05) higher confidence level for knowledge compared with the pre-final year students. Tetracyclines, penicillins, and sulphonamides represent the three most abused veterinary antimicrobials with similar ranking across countries. South African (69.7 ± 20.5) and Sudanese (68.1 ± 15.4) had significantly (p < 0.0001) higher mean scores compared to the Nigerian students (44.3 ± 6.8) in the student's ability to correctly match some specific antimicrobials against their classes but Nigerian students performed better in ranking antimicrobials. This survey revealed poor to average knowledge of antimicrobial stewardship among veterinary students with significant knowledge gaps across the countries. It is recommended that the relevant regulatory and standardization authorities should make concerted efforts and interventions to regularly review curricula to ensure the delivery of targeted formative and normative training, and improved lectures on antimicrobial usage and stewardship in order to improve the awareness and behaviors of future prescribers. The identified knowledge gaps of veterinary medical students on antimicrobial stewardship must be bridge to safeguard the future.


Assuntos
Gestão de Antimicrobianos , Adulto , Animais , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Nigéria , Percepção , África do Sul , Sudão , Adulto Jovem
3.
J S Afr Vet Assoc ; 90(0): e1-e8, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31714110

RESUMO

Understanding the knowledge and perceptions of veterinary students of antimicrobial resistance (AMR) as potential future prescribers of antimicrobials may serve as an opportunity to improve stewardship of AMR. Pre-final (n = 42) and final (n = 29) year veterinary students of the University of Pretoria completed questionnaires to determine their knowledge and perceptions of AMR. Of the 71 respondents, mixed practice (48%) and small animal practice (45%) were the most preferred career choices post-graduation, with the field of gross pathology being the least preferred. Over 80% of the respondents believed that veterinary practitioners' misuse of antimicrobials contributes to AMR and a higher percentage (98.6%) believed that farmers' misuse of antimicrobials encourages the development of AMR, in particular, in food animals (60.6%) compared to companion animals (50.7%). Agreement in the ranking of abuse of antimicrobials between pre-final and final year students was fair (36.4%; kappa 0.3), and the most abused antimicrobials in descending order listed by the students were tetracyclines, penicillins, sulphonamides and aminoglycosides. There was wide disparity between training and potential field application, as well as variations in the correct matching of antimicrobials to their respective antibiotic classes. Responses to the clinical application of antimicrobials also varied widely. Despite the apparent teaching of AMR to veterinary students, gaps may exist in the translation of theoretical concepts to clinical applications, hence the need for focused and targeted antimicrobial prescription and stewardship training to bridge these potential identified gaps.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Conhecimentos, Atitudes e Prática em Saúde , Estudantes de Ciências da Saúde/psicologia , Adulto , Animais , Antibacterianos/farmacologia , Escolha da Profissão , Feminino , Humanos , Masculino , África do Sul , Inquéritos e Questionários , Medicina Veterinária , Adulto Jovem
4.
J Sci Food Agric ; 98(2): 478-486, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28612391

RESUMO

BACKGROUND: There are concerns that fertilization using sludge in semi-arid areas, where water is limiting, will compound the effect of drought, resulting in the decline of yield from potential salt accumulation. This study investigated impacts of annual sludge application at 0, 4, 8 and 16 Mg ha-1 on weeping lovegrass hay yield, crude protein (CP) content, rainfall use efficiency (RUE), nitrogen use efficiency (NUE) and trace metal uptake over eight consecutive years. RESULTS: Both hay yield and RUE increased by 5-53% as the sludge rate increased. Hay yield was highest (13.3 Mg ha-1 ) during the wet season and RUE (27.1 kg mm-1 ) during the dry season. RUE was highest at sludge rates of 16 Mg ha-1 and NUE at 4 Mg ha-1 . Similarly, municipal sludge application increased CP content as well as crop Cr and Zn uptake from the 16 Mg ha-1 treatment. CONCLUSION: Results from this study indicated that eight consecutive years of treated municipal sludge application increased weeping lovegrass hay yield, CP content and RUE. Similarly, trace metal uptake by crop did not differ between the zero control and the 16 Mg ha-1 treatment, except for Zn and Cr, which showed a slight increment. Nonetheless, all trace metals remained well below the maximum tolerable dietary concentrations for domestic animals. © 2017 Society of Chemical Industry.


Assuntos
Metais/metabolismo , Poaceae/química , Esgotos/química , Poluentes do Solo/metabolismo , Oligoelementos/análise , Agricultura , Cidades , Secas , Metais/análise , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , Estações do Ano , Solo/química , Poluentes do Solo/análise , Oligoelementos/metabolismo , Água/análise , Água/metabolismo
5.
Curationis ; 38(1)2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26841921

RESUMO

BACKGROUND: South African nursing environments are marked by various incapacitating stressors. This study explores work-family (W-F) and family-work (F-W) conflicts as aspects of stress amongst nurses working with patients who have AIDS. OBJECTIVES: The study sought to determine the value of W-F and F-W conflicts as predictors of work and family satisfaction, as well as turnover intentions and the moderating role of supervisor and significant other support, amongst nurses caring for patients with AIDS in public hospitals within the Capricorn and Mopani districts, Limpopo Province. METHODS: The study used a cross-sectional design, with data collected at one point only. Ninety-one nursing staff provided the data for the study by completing structured, self-administered surveys. Analysis involved computing correlations of all study variables. Thereafter, associated variables were used as predictors. In each predictive analysis, the nurses' stress served as a control variable, W-F and F-W conflicts were the independent variables and significant others and supervisor supports were moderators. Interaction terms were derived from independent and moderator variables. RESULTS: Although the findings of the study were not generally supportive of the hypotheses advanced, they nevertheless showed, amongst other findings, that F-W conflict predicted work satisfaction whilst W-F conflict predicted turnover intentions. Moreover, significant other support had a direct effect on family satisfaction whilst supervisor support moderated reports of W-F conflict and experiences of work satisfaction. CONCLUSIONS: The study showed that inter-role models that appear to be established in the context of developed societies require some further investigations in South Africa.


Assuntos
Síndrome da Imunodeficiência Adquirida/enfermagem , Atitude do Pessoal de Saúde , Emprego/psicologia , Família , Enfermeiras e Enfermeiros/psicologia , Adulto , Conflito Psicológico , Estudos Transversais , Feminino , Humanos , Entrevistas como Assunto , Satisfação no Emprego , Masculino , Pessoa de Meia-Idade , África do Sul , Inquéritos e Questionários , Adulto Jovem
6.
J Biol Chem ; 266(19): 12223-7, 1991 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-2061307

RESUMO

Several peptides derived from the gastrin-predicted preprohormone sequence were isolated from a human gastrinoma by gel permeation, anion exchange, and reverse phase chromatography. The peptides were identified and characterized structurally by a combination of radioimmunoassays, mass spectral analysis, and microsequence analysis. The largest peptide, progastrin-(1-35) (cryptagastrin), extends from the putative processing site for the signal peptidase to the double basic residues adjacent to the amino terminus of gastrin 34. A shorter form of this peptide, progastrin-(6-35) (cryptagastrin-(6-35), was also isolated in smaller amounts. In addition, sulfated and nonsulfated gastrin 17 amides (progastrin-(55-71)) and the glycine-extended nonsulfated gastrin 17 (progastrin-(55-72)) were identified by radioimmunoassay, and their structures were confirmed by mass spectral analysis. Isolation of cryptagastrin indicates that the signal peptide of human preprogastrin contains 21 amino acid residues, and progastrin, therefore, contains 80 amino acids. There is minimal processing of the cryptic peptide preceding the sequence of gastrin 34. An amidated gastrin form larger than gastrin 34 could contain 71 amino acids. No evidence was obtained for processing that would produce gastrins containing more than 34 but less than 71 amino acid residues.


Assuntos
Gastrinoma/química , Gastrinas/metabolismo , Proteínas de Membrana , Peptídeos/isolamento & purificação , Precursores de Proteínas/metabolismo , Serina Endopeptidases , Sequência de Aminoácidos , Aminoácidos/análise , Cromatografia em Gel , Cromatografia por Troca Iônica , Endopeptidases/metabolismo , Humanos , Dados de Sequência Molecular , Peptídeos/química , Processamento de Proteína Pós-Traducional , Radioimunoensaio , Espectrometria de Massas de Bombardeamento Rápido de Átomos
7.
Biochem J ; 274 ( Pt 3): 731-8, 1991 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-2012601

RESUMO

Fibronectins are a class of cell-adhesion proteins produced from a single gene. The soluble plasma form is synthesized by hepatocytes and the insoluble cellular form by fibroblasts and other cell types. The proteins possess multiple binding domains for macromolecules including collagen, fibrin and heparin along with at least one cell-binding domain. Cellular as well as plasma fibronectins are dimers of similar but not identical polypeptides. Their differences are the result of internal amino acid sequence variability due to alternative RNA splicing in at least three regions (ED-A, ED-B and III CS). We have been studying this polymorphism at the protein level in plasma fibronectin (pFn). Cathepsin D-digested pFn applied to a heparin-agarose column and eluted with an NaCl stepwise gradient (0.1 M, 0.25 M and 0.5 M) released two polypeptides (75 kDa and 65 kDa) in the 0.5 M-NaCl peak. Immunoblots with monoclonal antibodies IST-2 (specific for the C-terminal heparin-binding domain) and AHB-3 (specific for the III CS domain) suggest that both peptides contain the C-terminal heparin-binding (Hep-2) domain, but that only the larger fragment possesses the III CS region. These two polypeptides (75 kDa and 65 kDa) were digested with trypsin, and the resulting peptides were analyzed by fast-atom-bombardment mass spectrometry and compared with the known cDNA-derived peptide sequence. Peptides that were unique to the III CS region were further characterized by micro sequence analysis. The 75 kDa fragment is derived from the A-chain and contains the III CS region (89 amino acid residues) along with the C-terminal heparin-binding (Hep-2) domain and the fibrin-binding (Fib-2) domain. A single galactosamine-based carbohydrate group was detected at Thr-73/74 of the III CS region present in the 75 kDa fragment. The 65 kDa fragment is derived from the B-chain and lacks the entire III CS region but does contain the Hep-2 and Fib-2 domains.


Assuntos
Fibronectinas/sangue , Alquilação , Sequência de Aminoácidos , Aminoácidos/análise , Western Blotting , Catepsina D/química , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Fibronectinas/genética , Humanos , Espectrometria de Massas , Dados de Sequência Molecular , Oxirredução , Mapeamento de Peptídeos , Splicing de RNA , Tripsina
8.
Mol Pharmacol ; 37(6): 911-5, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1694261

RESUMO

The glucuronide conjugates of oroxylin A and two other flavones, baicalein, and wogonin, were isolated from the methanol extract of the herb scutellariae radix (Huang Qin) and were found to be inhibitors of rat liver NAD(P)H:quinone acceptor oxidoreductase (EC 1.6.99.2). Baicalin (baicalein 7-O-glucuronide) and oroxylin-A 7-O-glucuronide are approximately 50-fold more potent than wogonin 7-O-glucuronide. The enzyme kinetic analysis revealed that oroxylin-A 7-O-glucuronide is a competitive inhibitor with respect to NADH (the electron donor), with a Ki value of 63 nM. Considering the similarities of their structures and inhibition kinetics to those of dicoumarol, it is thought that oroxylin-A 7-O-glucuronide and the other two flavonoids bind to an identical site and inhibit this quinone reductase in the same fashion as dicoumarol. The results also suggest that the inhibition of NAD(P)H:quinone acceptor oxidoreductase or another vitamin K reductase by oroxylin-A 7-O-glucuronide and the related flavonoids may be one of the steps associated with the anticoagulation action of the herb. These compounds are potentially useful anticoagulant drugs.


Assuntos
Anticoagulantes/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Flavonoides/farmacologia , Fígado/enzimologia , Quinona Redutases/antagonistas & inibidores , Animais , Dicumarol/farmacologia , Feminino , Glucuronatos/farmacologia , Cinética , Fígado/efeitos dos fármacos , Espectrometria de Massas , NAD(P)H Desidrogenase (Quinona) , Ratos , Ratos Endogâmicos
9.
Eur J Biochem ; 162(2): 403-11, 1987 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-3803394

RESUMO

Structural differences between the two subunits of human plasma fibronectin were studied by analyzing the carboxy-terminal heparin-binding domain (Hep-2). Two fragments (29 kDa and 38 kDa) derived from the Hep-2 domain were purified from thermolysin-digested human plasma fibronectin. Identical NH2-terminal sequences were obtained for both fragments through 16 Edman cycles. Neither domain contained the 90-amino-acid extra domain which is predicted by cDNA analysis of the cellular form of fibronectin. We have examined the primary structures of the 29-kDa and 38-kDa Hep-2 domains produced from the two chains of plasma fibronectin by analyzing the tryptic peptides by fast atom bombardment/mass spectrometry and comparison with the predicted fragments deduced from the corresponding cDNA-derived peptide sequences. Peptides that were unique to each domain were further characterized by microsequence analysis. The two domains showed identical amino acid sequences through 274 residues, followed by a region of variability. The 29-kDa domain contains 279 amino acids with an estimated relative molecular mass (Mr) of 30,460. This domain is located in the heavy chain of plasma fibronectin and contains three repeats of type III sequences plus a portion of the connecting segment (IIICS) region. The 38-kDa domain contains 359 amino acids and one O-linked glycosyl unit for an estimated Mr of 39,263. This domain is from the light chain of plasma fibronectin and contains four repeats of type III sequences with the deletion of the entire 120-amino-acid IIICS area. Secondary structure analysis by Chou/Fasman and circular dichroism reveals extensive beta-sheet structure for these domains. Key sulfhydryl and glycosylation sites are located near the mRNA splice junctions for the two chains. It is postulated that the splice junctions are adjacent to a flexible domain joining two regions of extensive beta-sheet structure.


Assuntos
Fibronectinas/sangue , Heparina/sangue , Sequência de Aminoácidos , Sítios de Ligação , Dicroísmo Circular , DNA/análise , Fibronectinas/genética , Humanos , Substâncias Macromoleculares , Fragmentos de Peptídeos/análise , Ligação Proteica , Conformação Proteica , Termolisina
10.
Biochemistry ; 25(19): 5391-5, 1986 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-3778866

RESUMO

We have identified the site labeled by arylazido-beta-alanyl-NAD+ (A3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NAD+) in rabbit muscle glyceraldehyde-3-phosphate dehydrogenase by microsequencing and fast atom bombardment mass spectrometry. This NAD+ photoaffinity analogue has been previously demonstrated to modify glyceraldehyde-3-phosphate dehydrogenase in a very specific manner and probably at the active site of the enzyme [Chen, S., Davis, H., Vierra, J. R., & Guillory, R. J. (1984) Biochem. Biophys. Stud. Proteins Nucleic Acids, Proc. Int. Symp., 3rd, 407-425]. The label is associated exclusively with a tryptic peptide that has the sequence Ile-Val-Ser-Asn-Ala-Ser-Cys-Thr-Thr-Asn. In comparison to the amino acid sequence of glyceraldehyde-3-phosphate dehydrogenase from other species, this peptide is in a highly conserved region and is part of the active site of the enzyme. The cysteine residue at position seven was predominantly labeled and suggested to be the site modified by arylazido-beta-alanyl-NAD+. This cysteine residue corresponds to the Cys-149 in the pig muscle enzyme, which has been shown to be an essential residue for the enzyme activity. The present investigation clearly demonstrates that arylazido-beta-alanyl-NAD+ is a useful photoaffinity probe to characterize the active sites of NAD(H)-dependent enzymes.


Assuntos
Marcadores de Afinidade/metabolismo , Azidas/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Músculos/enzimologia , NAD/análogos & derivados , Sequência de Aminoácidos , Animais , Espectrometria de Massas/métodos , NAD/metabolismo , Fragmentos de Peptídeos/análise , Coelhos , Tripsina
11.
J Biol Chem ; 261(18): 8128-33, 1986 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-3755132

RESUMO

The principal products derived from in vivo processing of anglerfish preproglucagon II were isolated and their structures determined. The structures were confirmed by a combination of automated Edman degradation, amino acid analysis, and fast atom bombardment mass spectrometry. The peptide corresponding to anglerfish preproglucagon II-(22-49) (numbering from the amino terminus of preproglucagon) was isolated intact and defines the site of signal cleavage to be between Gln-21 and Met-22. Glucagon from the anglerfish preproglucagon gene II was found to correspond to preproglucagon II-(52-80) (numbering from the amino terminus). Three forms of a glucagon-like peptide derived from preproglucagon II were also isolated. The structure of the longest form was consistent with the sequence of preproglucagon II-(89-122) deduced from the cDNA, His-Ala-Asp-Gly-Thr-Tyr-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Gln-Asp-Gln-Ala- Ala-Lys-Asp-Phe-Val-Ser-Trp-Leu-Lys-Ala-Gly-Arg-Gly-Arg-Arg-Glu. The carboxyl-terminal portion deduced from the cDNA remains intact in this form. A second form, preproglucagon II-(89-119) appears to result from proteolytic processing of the major form at the two adjacent arginine residues occurring at the carboxyl terminus. This second form has a glycine residue at its carboxyl terminus and is processed to the third form (preproglucagon II-(89-118)) which contains a carboxyl-terminal arginineamide. Radiolabeling studies in primary tissue culture support the observation that glucagon (preproglucagon II-(52-80], preproglucagon II-(89-122), and preproglucagon II-(89-119) are products of proglucagon processing in vivo.


Assuntos
Glucagon/metabolismo , Precursores de Proteínas/metabolismo , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Sequência de Bases , Cromatografia Líquida de Alta Pressão , DNA/análise , Peixes , Glucagon/análise , Glucagon/genética , Glucagon/isolamento & purificação , Humanos , Espectrometria de Massas , Proglucagon , Precursores de Proteínas/análise , Precursores de Proteínas/genética , Precursores de Proteínas/isolamento & purificação , Ratos , Especificidade da Espécie
12.
Hemoglobin ; 10(4): 379-400, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3528061

RESUMO

Ten abnormal hemoglobins were detected and characterized in individual cases referred to our laboratory for evaluation of hematological problems. Six of these variants were electrophoretically silent and could be detected by reverse phase high-performance liquid chromatography (HPLC) analysis. HPLC was also used to analyze the tryptic peptides of each individual variant. In most of these variants, secondary ion mass spectra of the mixture of the tryptic peptides could reveal the aberrant peptide and predict possible substitution through the mass difference between the normal and abnormal peptide. The mass spectra of the isolated abnormal peptide generally contained sufficient fragment ions to define the position of the amino acid substitution, obviating the need for lengthy sequencing procedures. Combination of the two techniques.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Hemoglobinas Anormais/isolamento & purificação , Espectrometria de Massas/métodos , Sequência de Aminoácidos , Globinas/isolamento & purificação , Hemoglobinas Anormais/genética , Humanos , Mutação , Fragmentos de Peptídeos/isolamento & purificação , Tripsina
13.
Biochem Biophys Res Commun ; 132(2): 520-5, 1985 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-4062939

RESUMO

Three peptides isolated from the atrial glands of Aplysia californica were analysed by Fast Atom Bombardment Mass Spectrometry. Survey scans over the mass range 1650 to 7500 at 500 resolution were used to locate signals for the protonated molecular ion and two subunits which result from cleavage of a single disulfide bond. A more accurate mass determination was made by accumulating scans over a narrow mass range. The amounts of sample used for each measurement ranged between 10 and 30 pmoles. Measured mass values are within 0.5 amu of calculated average molecular weights. Results illustrate the utility of the technique for accurate molecular weight determinations on limited quantities of high molecular weight peptides.


Assuntos
Aplysia/análise , Hormônios de Invertebrado/análise , Peptídeos/isolamento & purificação , Aminoácidos/análise , Animais , Glândulas Endócrinas/análise , Espectrometria de Massas , Peso Molecular
14.
J Biol Chem ; 259(22): 13703-11, 1984 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-6438080

RESUMO

Detergent-solubilized NADPH-cytochrome P-450 reductase was purified from porcine hepatic microsomes and compared to the rabbit enzyme isolated under identical conditions. The porcine enzyme had an equivalent specific activity toward cytochrome c compared to the rabbit enzyme. When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the porcine enzyme exhibited a major band at Mr = 80,000 and two additional bands at Mr = 20,000 and 60,000. The 20-kDa fragment was shown to be the COOH-terminal portion of the protein which contains a hydrophobic sequence of 28 residues homologous to the pyrophosphate-binding portion of the FAD-binding protein p-hydroxybenzoate hydroxylase. The 60-kDa fragment corresponded to the NH2-terminal portion of the protein since this peptide and the intact protein have blocked NH2 terminal. The trypsin-solubilized porcine enzyme has an NH2-terminal sequence which is homologous to the equivalent trypsin-solubilized enzymes from rat and rabbit (80% sequence homology). Eight cysteine-containing peptides were isolated from a tryptic digest of the S-carboxymethylated pig enzyme. Significant sequence homology was not found between these peptides and other flavoproteins, except for one peptide (Glu-Val-Gly-Glu-Thr-Leu-Leu-Tyr-Tyr-Gly-Cys-Arg) which exhibited partial homology with the known NADPH-binding site of glutathione reductase. When the NADPH-protected enzyme was first S-alkylated with unlabeled iodoacetate, NADPH depleted, and further alkylated with 14C-labeled iodoacetate, the above radiolabeled peptide was isolated from a tryptic digest. The equivalent peptide was also isolated by a similar procedure from rabbit liver cytochrome P-450 reductase.


Assuntos
Microssomos Hepáticos/enzimologia , NADPH-Ferri-Hemoproteína Redutase/análise , Fragmentos de Peptídeos/análise , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Cromatografia Líquida de Alta Pressão , Cisteína/análise , Eletroforese em Gel de Poliacrilamida , Glutationa Redutase/metabolismo , Peso Molecular , NADP/metabolismo , Coelhos , Ratos , Suínos , Tripsina/metabolismo
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