RESUMEN
Male fertility is the ability of sperm to fertilize the egg and sustain embryo development. Several factors determine the fertilizing capacity of mammalian sperm, including those intrinsic to sperm and components of the seminal plasma. The present study analyzed the seminal fluid proteome of Bos taurus and potential associations between proteins and fertility scores. Mass spectrometry coupled with nano HPLC allowed the identification of 1,159 proteins in the dairy bull seminal plasma. There were 50 and 29 seminal proteins more abundant in high (HF) low fertility (LF) bulls, respectively. Based on multivariate analysis, C-type natriuretic peptide, TIMP-2, BSP5 and sulfhydryl oxidase indicated relationship with HF bulls. Clusterin, tissue factor pathway inhibitor 2, galectin-3-binding protein and 5'-nucleotidase were associated with LF bulls. Abundance of NAD(P)(+)-arginine ADP-ribosyltransferase, prosaposin and transmembrane protein 2 proteins had the highest positive correlations with fertility ranking. Quantities of vitamin D-binding protein, nucleotide exchange factor SIL1 and galectin-3-binding protein showed the highest negative correlations with fertility ranking. A fertility ranking score was calculated and the relationship with these proteins was significant (Spearman's rho = 0.94). The present findings represent a major and novel contribution to the study of bovine seminal proteins. Indicators of fertility can be used to improve reproductive biotechnologies.
Asunto(s)
Industria Lechera , Fertilidad , Proteómica , Semen/metabolismo , Animales , Bovinos , Masculino , Fenotipo , Mapeo de Interacción de ProteínasRESUMEN
BACKGROUND: Aldosterone is involved in the process of renal allograft fibrosis, clinically manifest by proteinuria and allograft dysfunction, with increased risk for cardiovascular death. The treatment with aldosterone antagonists appears to be effective in controlling proteinuria, with a protective effect on progression of renal fibrosis. METHODS: This retrospective, cohort study included kidney transplant recipients from January 1993 to June 2015. Inclusion criteria were persistent proteinuria >0.5 g/d, longer than 6 months, and spironolactone therapy. RESULTS: One hundred forty transplant recipients fulfilled the inclusion criteria and were divided into 3 groups, according to proteinuria levels at the beginning of spironolactone therapy: low (<1 g/24 h), intermediate (1-3 g/24 h), and nephrotic (>3 g/24 h). Groups were comparable in demographic data, with a higher incidence of living related donors in the nephrotic group. In patients with proteinuria ≥1 g/d, we observed a significant reduction in proteinuria after 6 months of therapy that persisted over time. Blood pressure and glomerular filtration rate persisted stable over time. Adverse events were not severe to withdrawal therapy. CONCLUSIONS: Spironolactone can be a safe alternative to control post-transplant proteinuria, especially in patients with mild to moderate allograft dysfunction with proteinuria ≥1 g/day.
Asunto(s)
Diuréticos/uso terapéutico , Trasplante de Riñón/efectos adversos , Proteinuria/tratamiento farmacológico , Espironolactona/uso terapéutico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteinuria/etiología , Estudios RetrospectivosRESUMEN
Trypanosoma cruzi depends on the effectiveness of redox metabolism to survive and ensure infection in the host. Homeostasis of redox metabolism in T. cruzi is achieved by the actions of several proteins that differ in many aspects from host proteins. Although extensive research has been performed examining hydroperoxide cytosolic antioxidant defense centered on trypanothione, the mechanisms of mitochondrial antioxidant defense are not yet known. The aim of this study was to elucidate the partners of TcMPx antioxidant pathway and to determine the influence of the cellular context (physiological versus oxidative stress). Through co-precipitation coupled with a mass spectrometry approach, a variety of proteins were detected under physiological and oxidative stress conditions. Interestingly, functional category analysis of the proteins identified under physiological conditions showed that they were involved in the stress response, oxidoreduction, thiol transfer, and metabolic processes; this profile is distinct under oxidative stress conditions likely due to structural alterations. Our findings help to elucidate the reactions involving TcMPx and most importantly also reveal that this protein is present throughout the cell and that its interaction partners change following oxidative stress exposure. The involvement and significance of the proteins found to interact with TcMPx and other possible functions for this protein are discussed widening our knowledge regarding T. cruzi mitochondrial antioxidant defenses.
Asunto(s)
Mitocondrias/enzimología , Proteínas Mitocondriales/metabolismo , Peroxidasas/metabolismo , Proteínas Protozoarias/metabolismo , Trypanosoma cruzi/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Cromatografía Liquida , Electroforesis en Gel Bidimensional , Peróxido de Hidrógeno/farmacología , Microscopía Confocal , Proteínas Mitocondriales/genética , Oxidantes/farmacología , Peroxidasas/genética , Unión Proteica/efectos de los fármacos , Mapas de Interacción de Proteínas , Proteoma/genética , Proteoma/metabolismo , Proteómica/métodos , Proteínas Protozoarias/genética , Espectrometría de Masas en Tándem , Trypanosoma cruzi/enzimología , Trypanosoma cruzi/genéticaRESUMEN
We evaluated the effects of recreational football training combined with calorie-restricted diet (football + diet) vs calorie-restricted diet alone (diet) on aerobic fitness, lipid profile, and insulin resistance indicators in type 2 diabetes (T2D) patients. Forty-four T2D patients aged 48-68 years (27 females, 17 males) were randomly allocated to the football + diet group (FDG; n = 22) or to the diet group (DG; n = 22), of whom 19 FDG and 15 DG subjects completed the study. The football training was performed for 3 × 40 min/week for 12 weeks. Dual-energy X-ray absorptiometry scanning, treadmill testing, and fasting blood samplings were performed pre and post-intervention. After 12 weeks, maximal oxygen uptake (VO2max ) was elevated (P < 0.05) by 10 ± 4% in FDG but not in DG (-3 ± 4%, P < 0.05). After 12 weeks, reductions in blood triglycerides (0.4 ± 0.1 mmol/L), total cholesterol (0.6 ± 0.2 mmol/L), low-density lipoprotein, and very low-density lipoprotein levels were observed only in FDG. Fat mass decreased (P < 0.05) by 3.4 ± 0.4 kg in FDG and 3.7 ± 0.4 kg in DG. The lower (P < 0.05) glucagon and homeostatic model assessment of insulin resistance indicated an improvement in insulin sensitivity in FDG. In conclusion, football combined with restricted diet was effective in enhancing VO2max , reducing total cholesterol and triglycerides, and increasing insulin sensitivity, potentially providing better tools for the prevention of T2D complications than diet alone.
Asunto(s)
Colesterol/sangre , Diabetes Mellitus Tipo 2/terapia , Terapia por Ejercicio/métodos , Resistencia a la Insulina , Aptitud Física , Fútbol/fisiología , Triglicéridos/sangre , Anciano , Biomarcadores/sangre , Glucemia/metabolismo , Brasil , Restricción Calórica , Terapia Combinada , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Resultado del TratamientoRESUMEN
BACKGROUND: The prevalence of overweight individuals has increased in recent years. Moreover, the importance of a healthy diet is associated with the practice of physical activity and attempt to verify the achievement of physical exercise influences on food choice. However, it relationship between food intake and physical activity have not been studied. AIM: To evaluate if the period in which the trainings are conducted, morning and nocturne, interfere qualitatively and quantitatively in food consumption as well as verify possible associations between anthropometric profiles and dietary habits. METHODS: We collected data from 33 adult volunteers, between men and women, practitioners of bodybuilding. RESULTS: A total of 33 volunteers were interviewed (18 (54.5%) were men and 15 (45.5%) were women). Regarding anthropometric data, it turns out that that the volunteers of the two periods had similar characteristics, differentiating only weight. The consumption of nutritional supplements was observed in 30.77% of the practitioners in the morning period vs. 35% for the nocturne. Considering macronutrient intake, there was a significant difference in the consumption of protein between the periods. The consumption during nocturne period was greater (126 ± 5% of the daily requirement) than the morning period (115.7 ± 2%). As for micro-nutrients, calcium intake was greater among men when compared to women. There was a positive correlation between the BMI, and arm circumference for practitioners of the morning period. CONCLUSION: This study show that the practitioners who train in the morning have quietly better eating habits than those in the nocturne period, however both are inappropriate.
Asunto(s)
Índice de Masa Corporal , Fibras de la Dieta/farmacología , Grosor de los Pliegues Cutáneos , Levantamiento de Peso/fisiología , Adulto , Antropometría , Dieta , Ingestión de Alimentos , Conducta Alimentaria , Femenino , Humanos , Masculino , Factores de TiempoRESUMEN
BACKGROUND: The measurement of waist circumference (WC) is the most prevalent cause of the metabolic syndrome (MS). OBJECTIVE: The aim of this study was to correlate WC and BMI with high-density lipoprotein (HDL-c) levels in patients with MS being consulted by the Family Health Program (PSF), Brazil. METHODS: This cross-sectional study was conducted from September to November 2008 with 42 patients (29 women and 13 men) from 35 to 77 years. Dietary intake was reported, and biochemical and body composition measures were taken. RESULTS: The HDL-c levels were higher in women when compared to men (48.4 ± 8.1 mg/dL vs. 36.4 ± 7.8 mg/dL). However, the triglycerides (TG)/HDL-c ratio and TG concentrations were lower in women (3.8 ± 1.5 and 178.0 ± 57.8 mg/dL, respectively) than in men (9.4 ± 8.5 and 471.5 ± 501.5 mg/dL, respectively). Regarding skinfold profile, the triceps was greater in females (37.0 ± 8.4 cm vs. 20.7 ± 10.5 cm). The dietetic profile showed that women had a lower intake of energy, fiber, phosphorus and sodium. The fruits and vegetables intake was diminished in the participants of this study, as less than 60% of the women and 50% of men met the daily recommendations. Approximately 54% of men and 28% of women had a lower intake of dairy products daily. Moreover, the results shows that the WC was negatively correlated to HDL-c (r = -0.41, p < 0.05) whereas the BMI is not associated with HDL-c (r = -0.34, p > 0.06). CONCLUSION: Our findings showed that WC is a better predictor of changes in HDL-c than BMI.
Asunto(s)
Índice de Masa Corporal , Lipoproteínas HDL/sangre , Síndrome Metabólico/sangre , Síndrome Metabólico/patología , Circunferencia de la Cintura/fisiología , Adulto , Anciano , Composición Corporal/fisiología , Brasil , Estudios Transversales , Productos Lácteos , Dieta , Ingestión de Alimentos , Ingestión de Energía , Femenino , Frutas , Humanos , Masculino , Carne , Persona de Mediana Edad , Obesidad/diagnóstico , Grosor de los Pliegues Cutáneos , Verduras , Adulto JovenRESUMEN
Cassava roots have a low-protein content (0.7-2%). Amino acids such as lysine and methionine are also low, and some research reports have indicated the absence of methionine. The amino acid profiles of a common cassava cultivar and an interspecific hybrid, namely ICB 300, were determined using the computerized amino acid analyzer Hitachi L-8500. The interspecific hybrid has 10 times more lysine and 3 times more methionine than the common cassava cultivar: lysine content was 0.010 g per 100 g in the common cassava cultivar while it reached 0.098 in the interspecific hybrid. Methionine in the common cassava cultivar was 0.014 g per 100 g whereas it reached 0.041 g per 100 g in the interspecific hybrid. Total amino acid content in the common cassava cultivar was 0.254 g per 100 g viz. a viz. 1.664 g per 100 g in the interspecific hybrid. The genetic variability of the profile and quantity of amino acids indicate the feasibility of selecting interspecific hybrids that are rich in both crude protein and amino acids. This is the first report of high true protein in cassava root.
Asunto(s)
Aminoácidos/análisis , Manihot/química , Manihot/genética , Proteínas en la Dieta/análisis , Hibridación Genética , Lisina/análisis , Metionina/análisis , Necesidades Nutricionales , Raíces de Plantas/químicaRESUMEN
Cassava roots have a low-protein content (0.7-2%). Amino acids such as lysine and methionine are also low, and some research reports have indicated the absence of methionine. The amino acid profiles of a common cassava cultivar and an interspecific hybrid, namely ICB 300, were determined using the computerized amino acid analyzer Hitachi L-8500. The interspecific hybrid has 10 times more lysine and 3 times more methionine than the common cassava cultivar: lysine content was 0.010 g per 100 g in the common cassava cultivar while it reached 0.098 in the interspecific hybrid. Methionine in the common cassava cultivar was 0.014 g per 100 g whereas it reached 0.041 g per 100 g in the interspecific hybrid. Total amino acid content in the common cassava cultivar was 0.254 g per 100 g viz. a viz. 1.664 g per 100 g in the interspecific hybrid. The genetic variability of the profile and quantity of amino acids indicate the feasibility of selecting interspecific hybrids that are rich in both crude protein and amino acids. This is the first report of high true protein in cassava root.
Asunto(s)
Aminoácidos/análisis , Manihot/química , Manihot/genética , Hibridación Genética , Lisina/análisis , Metionina/análisis , Necesidades Nutricionales , Proteínas en la Dieta/análisis , Raíces de Plantas/químicaRESUMEN
The Nelore bull (Bos taurus indicus) seminal plasma proteome was analyzed by MALDI-TOF MS and two-dimensional gel electrophoresis. A total of 260 spots were visualized in the 2-DE gel (pI range 3-10) and 13 spots could be identified by peptide mass fingerprinting corresponding to 11 different polypeptides. The results allowed the creation of the first proteomic map of Bos taurus indicus seminal plasma. The roles of the identified proteins in the bull seminal plasma are discussed.
Asunto(s)
Proteoma/análisis , Semen/química , Animales , Bovinos , Electroforesis en Gel Bidimensional/métodos , Masculino , Mapeo Peptídico , Proteoma/química , Proteínas de Plasma Seminal/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Estimaram-se as correlações entre fertilidade e concentrações de proteínas, açúcares redutores e 17 tipos de aminoácidos livres do plasma seminal de 19 touros Nelore, adultos, doadores de sêmen de alta qualidade segundo as análises físicas e morfológicas. O escore de fertilidade foi estimado de acordo com a porcentagem de gestação das fêmeas cobertas em três estações de monta consecutivas, por inseminação artificial ou monta natural. Foi observada alta variabilidade na concentração das moléculas analisadas nas amostras. O coeficiente de correlação estimado entre concentrações de proteína e de açúcares redutores foi de 0,90. Individualmente, nenhum dos componentes quantificados apresentou correlação significativa com a fertilidade dos touros.
Asunto(s)
Animales , Bovinos , Fertilidad , SemenRESUMEN
Arginine, as a basic amino acid, can alter the pH of a parenteral solution and consequently to interfere in the stability of other amino acids. The objective of this study was to analyze the chemical stability of amino acids in solutions for parenteral nutrition with arginine supplementation. Amino acids concentrations were determined using an amino acid analyzer in intervals of 12, 36, 72 hours, 7 and 28 days. Storage temperatures were -20 degrees C, 5 degrees C and 25 degrees C. A decrease was observed (p < 0.05) in the concentrations of threonine, methionine, isoleucine, leucine, proline and lysine on the 28th day of study, in the solutions kept at 25 degrees C. The side chains of threonine, methionine, isoleucine, leucine, proline and lysine have hydrophobic groups, which renders them less soluble in water when compared to amino acids that have polar side chains. The degradation of lysine was significant in the sample of parenteral nutrition supplemented with arginine, possibly due to the fact that the solution's pH was between 7.5 and 7.6, therefore facilitating the Maillard reaction between lysine and glucose.
Asunto(s)
Aminoácidos/química , Suplementos Dietéticos , Emulsiones/química , Reacción de Maillard , Nutrición Parenteral , Aminoácidos/administración & dosificación , Arginina , Estabilidad de Medicamentos , Reacción de Maillard/efectos de los fármacosRESUMEN
In this study, the behavioral and electroencephalographic (EEG) analysis of seizures induced by the intrahippocampal injection in rats of granulitoxin, a neurotoxic peptide from the sea anemone Bunodosoma granulifera, was determined. The first alterations occurred during microinjection of granulitoxin (8 µg) into the dorsal hippocampus and consisted of seizure activity that began in the hippocampus and spread rapidly to the occipital cortex. This activity lasted 20-30 s, and during this period the rats presented immobility. During the first 40-50 min after its administration, three to four other similar short EEG seizure periods occurred and the rats presented the following behavioral alterations: akinesia, facial automatisms, head tremor, salivation, rearing, jumping, barrel-rolling, wet dog shakes and forelimb clonic movements. Within 40-50 min, the status epilepticus was established and lasted 8-12 h. These results are similar to those observed in the acute phase of the pilocarpine model of temporal lobe epilepsy and suggest that granulitoxin may be a useful tool not only to study the sodium channels, but also to develop a new experimental model of status epilepticus.
Asunto(s)
Animales , Masculino , Ratas , Conducta Animal/efectos de los fármacos , Electroencefalografía/métodos , Neurotoxinas/toxicidad , Péptidos/toxicidad , Anémonas de Mar , Convulsiones/inducido químicamente , Venenos de Cnidarios/toxicidad , Hipocampo/efectos de los fármacos , Microinyecciones , Ratas Wistar , Convulsiones/fisiopatología , Factores de TiempoRESUMEN
In this study, the behavioral and electroencephalographic (EEG) analysis of seizures induced by the intrahippocampal injection in rats of granulitoxin, a neurotoxic peptide from the sea anemone Bunodosoma granulifera, was determined. The first alterations occurred during microinjection of granulitoxin (8 microg) into the dorsal hippocampus and consisted of seizure activity that began in the hippocampus and spread rapidly to the occipital cortex. This activity lasted 20-30 s, and during this period the rats presented immobility. During the first 40-50 min after its administration, three to four other similar short EEG seizure periods occurred and the rats presented the following behavioral alterations: akinesia, facial automatisms, head tremor, salivation, rearing, jumping, barrel-rolling, wet dog shakes and forelimb clonic movements. Within 40-50 min, the status epilepticus was established and lasted 8-12 h. These results are similar to those observed in the acute phase of the pilocarpine model of temporal lobe epilepsy and suggest that granulitoxin may be a useful tool not only to study the sodium channels, but also to develop a new experimental model of status epilepticus.
Asunto(s)
Conducta Animal/efectos de los fármacos , Electroencefalografía/efectos de los fármacos , Neurotoxinas/toxicidad , Péptidos/toxicidad , Anémonas de Mar , Convulsiones/inducido químicamente , Animales , Venenos de Cnidarios/toxicidad , Electroencefalografía/métodos , Hipocampo/efectos de los fármacos , Masculino , Microinyecciones , Neurotoxinas/administración & dosificación , Péptidos/administración & dosificación , Ratas , Ratas Wistar , Convulsiones/fisiopatología , Factores de TiempoRESUMEN
Arginine, as a basic amino acid, can alter the pH of a parenteral solution and consequently to interfere in the stability of other amino acids. The objective of this study was to analyze the chemical stability of amino acids in solutions for parenteral nutrition with arginine supplementation. Amino acids concentrations were determined using an amino acid analyzer in intervals of 12, 36, 72 hours, 7 and 28 days. Storage temperatures were -20 degrees C, 5 degrees C and 25 degrees C. A decrease was observed (p < 0.05) in the concentrations of threonine, methionine, isoleucine, leucine, proline and lysine on the 28th day of study, in the solutions kept at 25 degrees C. The side chains of threonine, methionine, isoleucine, leucine, proline and lysine have hydrophobic groups, which renders them less soluble in water when compared to amino acids that have polar side chains. The degradation of lysine was significant in the sample of parenteral nutrition supplemented with arginine, possibly due to the fact that the solution's pH was between 7.5 and 7.6, therefore facilitating the Maillard reaction between lysine and glucose.
Asunto(s)
Aminoácidos/química , Suplementos Dietéticos , Emulsiones/química , Reacción de Maillard , Nutrición Parenteral , Aminoácidos/administración & dosificación , Arginina/administración & dosificación , Arginina/química , Estabilidad de Medicamentos , Reacción de Maillard/efectos de los fármacosRESUMEN
A new xylanase activity (XynII) was isolated from liquid state cultures of Acrophialophora nainiana containing birchwood xylan as carbon source. XynII was purified to apparent homogeneity by gel filtration and ion exchange chromatographies. The enzyme was optimally active at 55 degrees C and pH 7.0. XynII had molecular mass of 22630+/-3.0 and 22165 Da, as determined by mass spectrometry and SDS-PAGE, respectively. The purified enzyme was able to act only on xylan as substrate. The apparent K(m) values on soluble and insoluble birchwood xylans were 40.9 and 16.1 mg ml(-1), respectively. The enzyme showed good thermal stability with half lives of 44 h at 55 degrees C and ca. 1 h at 60 degrees C The N-terminal sequence of XynII showed homology with a xylanase grouped in family G/11. The enzyme did not show amino acid composition similarity with xylanases from some fungi and Bacillus amyloliquefaciens.
Asunto(s)
Hongos Mitospóricos/enzimología , Xilosidasas/aislamiento & purificación , Secuencia de Aminoácidos , Aminoácidos/química , Datos de Secuencia Molecular , Análisis de Secuencia de Proteína , Homología de Secuencia de Aminoácido , Xilano Endo-1,3-beta-Xilosidasa , Xilosidasas/química , Xilosidasas/metabolismoRESUMEN
Os efeitos da suplementaçao com arginina na dieta de portadores de cancer sao controversos. O objetivo deste trabalho é avaliar os efeitos da suplementacao dietética com arginina no crescimento tumoral, disseminaçao metastática, metabolismo de aminóacidos, alteraçoes hematológicas, tempo de sobrevida e peso corporal de ratos Wistar com tumor sólido de Walker 256. Foram administradas soluçoes por via gástrica, contendo arginina nas concentraçoes de 4 por cento, 6 por cento e dieta padrao (controle). A suplementacao com arginina inibiu a desseminaçao de células tumorais no modelo experimental, embora crescimento tumoral nao tenha sido afectado significantemente. O tempo de sobrevida dos animais com tumor sólido nao foi afetado de forma significativa. Foi observado disminuiçao significativa de peso corpóreo após a administraçao da arginina a 6 por cento (p<0.05). O metabolismo dos aminóacidos foi estimulado após ingestao de suplementos com arginina, evidenciado pelos aumentos significativos dos níveis sanguíneos de arginina, ornitina, citrulina, prolina e histidina quando comparados ao grupo controle (p<0.001). O grau de anemia no tumor sólido foi menos severo nos grupos que receberam suplementaçao com arginina, evidenciado através do hemograma (p<0.001) e da análise citológica. Os resultados sugerem que a suplementaçao dietética com arginina a 6 por cento apresentou algum efeito benéfico no tumor sólido de Walker 256 que ultrapassa o efeito nutricional
Asunto(s)
Ratones , Animales , Arginina , Suplementos Dietéticos , Metabolismo , Neoplasias , Brasil , Ciencias de la NutriciónRESUMEN
The effects of diet arginine supplementation for those with cancer are controversial. We evaluate the effects of dietetic supplementation with arginine over body weight, growth of tumor, metastatic dissemination, surviving time, amino acid metabolism, haematological changes of the rats with Walker 256 solid tumor. Intragastrical solutions with arginine at 4% and 6%, a standard diet (control) were administered to the animals. The supplementation with arginine was associated with a lower weight gain during the study period (p < 0.05). Surviving time of the rats with solid tumor did not vary significantly between the groups. The rate of metastase was lower in animals with Walker 256 solid tumor supplemented with arginine. The amino acid metabolism was estimulate in the animals after arginine supplementation at 4% and 6%, demonstrated by significant increases in blood levels of arginine, ornitine, citruline, proline and histidine when compared to the control group. Anaemia was less severe in the rats with Walker 256 solid tumor that received arginine supplementation. The results suggest that arginine 6% supplementation may have pharmacologic effect in rats with Walker 256 solid beyond the nutritional one.
Asunto(s)
Arginina/uso terapéutico , Carcinoma 256 de Walker/tratamiento farmacológico , Suplementos Dietéticos , Aminoácidos/sangre , Análisis de Varianza , Animales , Peso Corporal , Estudios de Casos y Controles , Supervivencia sin Enfermedad , Ensayos de Selección de Medicamentos Antitumorales , Masculino , Ratas , Ratas WistarRESUMEN
A new xylanase (XYL2) was purified from solid-state cultures of Trichoderma harzianum strain C by ultrafiltration and gel filtration. SDS-PAGE of the xylanase showed an apparent homogeneity and molecular weight of 18 kDa. It had the highest activity at pH 5.0 and 45 degrees C and was stable at 50 degrees C and pH 5.0 up to 4 h xylanase. XYL2 had a low Km with insoluble oat spelt xylan as substrate. Compared to the amino acid composition of xylanases from Trichoderma spp, xylanase XYL2 presented a high content of glutamate/glutamine, phenylalanine and cysteine, and a low content of serine. Xylanase XYL2 improved the delignification and selectivity of unbleached hardwood kraft pulp.
Asunto(s)
Trichoderma/enzimología , Xilosidasas/aislamiento & purificación , Aminoácidos/análisis , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Peso Molecular , Ultrafiltración , Madera , Xilano Endo-1,3-beta-Xilosidasa , Xilosidasas/química , Xilosidasas/metabolismoRESUMEN
Paracoccidioides brasiliensis is the causal agent of paracoccidioidomycosis, which is a systemic mycosis in Latin America. This human pathogen is a dimorphic fungus existing as mycelium (26 degrees C) and in infected tissues as a yeast form (36 degrees C). The in vitro differentiation process is reversible and dependent on temperature shift. In the present study, the total proteins from both forms of P. brasiliensis (isolate Pb01) were analysed by two-dimensional electrophoresis. Differentially expressed proteins were identified. Two of these proteins, PbM46 (mycelium) and PbY20 (yeast), were submitted to automated protein sequencing of their N-terminal regions. The 15 amino acid residue sequence of PbM46, AITKIFALKVYDSSG, is similar to enolases from several sources, and specially those from Saccharomyces cerevisiae (80%) and Candida albicans (67%), when compared to the NR database at NCBI using the BLASTP program. The 34 amino acid residue sequence of PbY20, APKIAIVFYSLYGHIQKLAEAQKKGIEAAGGTAD, could probably represent an allergen protein since it is very similar (90%) to the minor allergen protein of Alternaria alternata and 82% similar to the allergen protein of Cladosporium herbarum. This comparative analysis of proteins from mycelium and yeast forms has allowed the identification and characterization of differentially expressed proteins, probably related to differential gene expression in P. brasiliensis.