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1.
Optom Vis Sci ; 88(2): 257-62, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21169874

RESUMO

PURPOSE: Goji berry (Lycium barbarum L.) is purported to benefit vision because of its high antioxidant (especially zeaxanthin) content, although this effect has not been demonstrated in high-quality human studies. The purpose of this study was to evaluate the effects of daily supplementation with a proprietary milk-based formulation of goji berry, Lacto-Wolfberry (LWB), on macular characteristics and plasma zeaxanthin and antioxidant capacity levels in elderly subjects. METHODS: This was a double-masked, randomized, placebo-controlled trial in healthy elderly subjects (range, 65 to 70 years) receiving 13.7 g/d of LWB (n = 75) or placebo (n = 75) for 90 days. Subjects underwent direct ophthalmic examination to assess pigmentation and soft drusen count in the macula and a blood draw to measure plasma zeaxanthin level and total antioxidant capacity. RESULTS: The placebo group demonstrated hypopigmentation and soft drusen accumulation in the macula, whereas the LWB group remained stable. Both plasma zeaxanthin level and antioxidant capacity increased significantly in the LWB group, by 26% and 57%, respectively, but did not change in the placebo group. No product-related adverse events were reported in either group. CONCLUSIONS: Overall, daily dietary supplementation with goji berry for 90 days increases plasma zeaxanthin and antioxidant levels as well as protects from hypopigmentation and soft drusen accumulation in the macula of elderly subjects. However, the mechanism of action is unclear, given the lack of relationship between change in plasma zeaxanthin and change in macular characteristics.


Assuntos
Antioxidantes/metabolismo , Suplementos Nutricionais , Lycium , Macula Lutea/efeitos dos fármacos , Degeneração Macular/prevenção & controle , Preparações de Plantas/farmacologia , Xantofilas/sangue , Idoso , Método Duplo-Cego , Feminino , Humanos , Lycium/efeitos adversos , Macula Lutea/fisiopatologia , Degeneração Macular/etiologia , Masculino , Pigmentação/efeitos dos fármacos , Preparações de Plantas/efeitos adversos , Estudos Prospectivos , Drusas Retinianas/patologia , Fatores de Risco , Zeaxantinas
2.
Neurochem Res ; 35(5): 702-11, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20131093

RESUMO

Lycium barbarum (Fructus Lycii, Wolfberry, or Gouqi) belongs to the Solanaceae. The red-colored fruits of L. barbarum have been used for a long time as an ingredient in Chinese cuisine and brewing, and also in traditional Chinese herbal medicine for improving health. However, its effects on cognitive function have not been well studied. In the present study, prevention of a milk-based wolfberry preparation (WP) on cognitive dysfunction was tested in a prenatal stress model with rats and the antioxidant mechanism was tested by in vitro experiments. We found that prenatal stress caused a significant decrease in cognitive function (Morris water maze test) in female offspring. Pretreatment of the mother rats with WP significantly prevented the prenatal stress-induced cognitive dysfunction. In vitro studies showed that WP dose-dependently scavenged hydroxyl and superoxide radicals (determined by an electron spin resonance spectrometric assay), and inhibited FeCl(2)/ascorbic acid-induced dysfunction in brain tissue and tissue mitochondria, including increases in reactive oxygen species and lipid peroxidation and decreases in the activities of complex I, complex II, and glutamate cysteine ligase. These results suggest that dietary supplementation with WP may be an effective strategy for preventing the brain oxidative mitochondrial damage and cognitive dysfunction associated with prenatal stress.


Assuntos
Antioxidantes/farmacologia , Transtornos Cognitivos/prevenção & controle , Lycium/química , Mitocôndrias/efeitos dos fármacos , Extratos Vegetais/farmacologia , Efeitos Tardios da Exposição Pré-Natal , Animais , Ácido Ascórbico/farmacologia , Feminino , Compostos Ferrosos/farmacologia , Sequestradores de Radicais Livres/metabolismo , Glutamato-Cisteína Ligase/antagonistas & inibidores , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Leite , Mitocôndrias/metabolismo , Estresse Oxidativo , Gravidez , Ratos , Ratos Sprague-Dawley , Restrição Física , Estresse Psicológico/complicações
3.
Arch Microbiol ; 192(11): 959-68, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20844866

RESUMO

We first used human flora-associated (HFA) piglets, a significantly improved model for research on human gut microbiota, to study the effects of short-chain fructo-oligosaccharides (scFOS) on the gut bacterial populations. Ten neonatal HFA piglets were assigned to receive basal diets alone or supplemented with scFOS (0.5 g/kg body weight/day) from 1 to 37 days after birth (DAB). The impact of scFOS on the fecal bacterial populations of the piglets before (12 DAB), during (17 DAB), and after (25 and 37 DAB) weaning were monitored by PCR-denaturing gradient gel electrophoresis and real-time quantitative PCR. The Bifidobacterium genus was stimulated consistently, except during weaning, confirming the bifidogenic property of scFOS. At 12 DAB, the Clostridium leptum subgroup was decreased and two unknown Bacteroides-related species were increased; at 25 DAB, the C. leptum subgroup and Subdoligranulum variabile-like species were elevated, whereas one unknown Faecalibacterium-related species was suppressed; and at 37 DAB, the Bacteroides genus was decreased. The results showed that effects of scFOS on non-bifidobacteria varied at different developmental stages of the animals, warranting further investigation into the host-development-related effects of prebiotics on the gut microbiota and the host physiology using the HFA piglets as a model for humans.


Assuntos
Fezes/microbiologia , Oligossacarídeos/farmacologia , Prebióticos , Adulto , Animais , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/genética , Eletroforese em Gel de Gradiente Desnaturante , Humanos , Masculino , Modelos Animais , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Suínos
4.
J Agric Food Chem ; 55(14): 5523-8, 2007 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-17552542

RESUMO

The effects of tea water extracts (TWE), crude tea polysaccharides (CTP), and a tea polysaccharide fraction (TPF) were tested on hyperglycemic diabetic mice. Results indicated that TWE, CTP, and TPF could significantly decrease fasting blood glucose (FBG) and glucosylated serum protein (GSP) in alloxan-induced diabetic mice compared to the control group. In vitro antioxidant activities of TWE, CTP, and TPF for scavenging hydroxyl radicals and superoxide radicals decreased with the degree of purification and were lowest for TPF. High-performance gel permeation chromatography (HPGPC) and component analysis revealed the molecular mass distribution and constituents of TWE, CTP, and TPF, indicating that a 100-120 kDa fraction contained the hypoglycemic activity. This fraction was essentially composed of polysaccharides (approximately 90%) with substantial amounts of arabinogalactan proteins. The second-derivative IR spectra of TWE, CTP, and TPF with peak intensity around 1075 and 1045 cm(-1), which characterize galactopyranose in the backbone and arabinofuranose units in side branches, respectively, further substantiated the importance of the arabinogalactan proteins. Taken together, the results indicate that a soluble tea polysaccharide is the major hypoglycemic factor in tea and that this polysaccharide may be developed to a potential natural hypoglycemic functional ingredient.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Polissacarídeos/uso terapêutico , Chá/química , Animais , Antioxidantes/farmacologia , Glicemia/análise , Masculino , Camundongos , Polissacarídeos/farmacologia , Solubilidade
5.
J Agric Food Chem ; 50(12): 3527-32, 2002 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-12033823

RESUMO

The contribution of the chemical composition to the flavor of cocoa liquor from an Ecuadorian selfed population of clone EET 95 was investigated. Polyphenols, purine alkaloids, organic acids, and sugars were quantified, and the key sensory characteristics of cocoa were scored by a trained panel. Despite the short bean fermentation (2 days) commonly used for Arriba cocoa, acetic acid content was closely correlated to liquor pH, demonstrating its essential role in cocoa liquor acidification. Polyphenols were positively correlated to astringency, bitterness, and the green note and negatively correlated to the fruity character. Alkaloid and polyphenol levels fluctuated significantly within the selfed progeny and tended to be lower than those of the heterozygous clone EET 95 (inbreeding effect). These results support the idea that polyphenols might be essential to the overall perception of cocoa liquor characteristics and indicate that the composition and the sensory quality of cocoa liquor are the result of both a genotypic contribution and the conditions of fermentation and roasting.


Assuntos
Cacau/química , Flavonoides , Paladar , Ácido Acético/análise , Alcaloides/análise , Cacau/genética , Carboidratos/análise , Ácidos Carboxílicos/análise , Fermentação , Concentração de Íons de Hidrogênio , Fenóis/análise , Estruturas Vegetais/química , Polímeros/análise , Polifenóis , Soluções , Especificidade da Espécie
6.
Rejuvenation Res ; 15(1): 89-97, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22352435

RESUMO

Wolfberry (fruit of Lycium barbarum) has been prized for many years in China for its immunomodulatory property and its high specific antioxidant content. However, clear clinical evidence demonstrating the effect of wolfberry dietary supplementation is still lacking. After our earlier report showing that a proprietary milk-based wolfberry formulation (Lacto-Wolfberry) enhances in vivo antigen-specific adaptive immune responses in aged mice, the present study aimed at demonstrating the effect of dietary Lacto-Wolfberry supplementation on immune functions in the elderly, especially vaccine response known to decline with aging. A 3-month randomized, double-blinded, placebo-controlled study was conducted on 150 healthy community-dwelling Chinese elderly (65-70 years old) supplemented with Lacto-Wolfberry or placebo (13.7 grams/day). Immune response to influenza vaccine was assessed in the study, along with inflammatory and physical status. No serious adverse reactions were reported during the trial, neither symptoms of influenza-like infection. No changes in body weight and blood pressure, blood chemistry or cells composition, as well as autoantibodies levels were observed. The subjects receiving Lacto-Wolfberry had significantly higher postvaccination serum influenza-specific immunoglobulin G levels and seroconversion rate, between days 30 and 90, compared with the placebo group. The postvaccination positive rate was greater in the Lacto-Wolfberry group compared to the placebo group, but did not reach statistical significance. Lacto-Wolfberry supplementation had no significant effect on delayed-type hypersensitivity response and inflammatory markers. In conclusion, long-term dietary supplementation with Lacto-Wolfberry in elderly subjects enhances their capacity to respond to antigenic challenge without overaffecting their immune system, supporting a contribution to reinforcing immune defense in this population.


Assuntos
Dieta , Suplementos Nutricionais , Sistema Imunitário/efeitos dos fármacos , Lycium/metabolismo , Idoso , Antígenos/química , Autoanticorpos/química , Separação Celular , China , Método Duplo-Cego , Feminino , Citometria de Fluxo/métodos , Humanos , Hipersensibilidade Tardia , Imunoglobulina G/metabolismo , Fatores Imunológicos , Inflamação , Masculino , Orthomyxoviridae/metabolismo , Placebos
7.
Antioxid Redox Signal ; 16(3): 275-89, 2012 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21905985

RESUMO

AIMS: Docosahexaenoic acid (22:6n-3; DHA) is known to play a critical role in postnatal brain development. However, no study has been performed to investigate its preventive effect on prenatal stress-induced behavioral and molecular alterations in offspring. In the present study, rats were exposed to restraint stress on days 14-20 of pregnancy, three times a day, 2 hours each time; DHA was given at the doses of 100 and 300 mg/kg/day for two weeks. RESULTS: We showed that prenatal restraint stress caused (1) learning and memory impairment, (2) BDNF mRNA level decrease, (3) oxidative damage to proteins, (4) enhanced expression of nitric oxide synthase and apoptosis, and (5) abnormalities in mitochondrial metabolism that included changes in mitochondrial complexes I-V, and enhancement of expression of proteins involved in mitochondrial fusion/fission (Mfn-1, Mfn-2, Drp-1) and autophagy (Atg3, Atg7, Beclin-1, p-Akt, and p-mTOR) in the hippocampus of offspring. INNOVATION: Besides the well-known role in child brain development, we reported the novel finding of DHA in protecting prenatal stress-induced cognitive dysfunction involving the modulation of mitochondrial function and dynamics. CONCLUSION: Maternal feeding of DHA significantly prevented prenatal stress-induced impairment of learning and memory and normalized the biomarkers of oxidative damage, apoptosis, and mitochondrial metabolism in the hippocampus of both male and female offspring. These results suggest that maternal feeding of DHA exerts preventive effects on prenatal stress-induced brain dysfunction and that modulation of mitochondrial metabolism may play critical role in DHA protection.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Deficiências da Aprendizagem/prevenção & controle , Mitocôndrias/metabolismo , Neurônios/metabolismo , Estresse Oxidativo , Efeitos Tardios da Exposição Pré-Natal , Estresse Psicológico/complicações , Animais , Apoptose , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/prevenção & controle , Ácidos Docosa-Hexaenoicos/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Deficiências da Aprendizagem/etiologia , Masculino , Troca Materno-Fetal , Aprendizagem em Labirinto , Mitocôndrias/enzimologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Neurônios/enzimologia , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Gravidez , Carbonilação Proteica , Ratos , Ratos Sprague-Dawley , Transcrição Gênica
8.
J Agric Food Chem ; 57(12): 5121-8, 2009 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-19456132

RESUMO

A rapid methodology of quality control was developed for arabinogalactan proteins (AGP) extracted and purified from green tea. Using the vectorial angle method and IR spectrum analysis, the 1200-800 cm(-1) region in second-derivative IR spectra was determined as the key fingerprinting region of green tea AGP, with the 1090-900 cm(-1) region reflecting their conservative and common characteristics. In fact, the key monosaccharides, galactose (Gal) and arabinose (Ara), were shown to have intense peaks at about 1075 and 1045 cm(-1), respectively, and uronic acids at about 1018 cm(-1) in second-derivative IR spectra. The variable region was identified to be at about 1134-1094 and 900-819 cm(-1) and was probably due to compositional and structural differences between AGPs. The constructed methodology was tested on green tea AGP extracted by three treatments and purified to apparent homogeneity as water-extracted Camellia sinensis AGP (CSW-AGP), pectinase-extracted C. sinensis AGP (CSP-AGP), and trypsin-extracted C. sinensis AGP (CST-AGP) with an Ara/Gal ratio of 1.37, 1.57, and 1.82, respectively. Regarding in vitro antioxidant activity, the AGPs (CSW-AGP and CST-AGP) with higher similarity (closer cos theta values calculated for second-derivative IR spectra) exhibited a similar ability of chelating ferrous ions and had a similar capability for scavenging hydroxyl radicals. In conclusion, the combination of second-derivative IR spectrum analysis and the vectorial angle method has allowed a successful characterization of green tea AGPs and was shown to be suitable for their compositional and activity discrimination and rapid quality evaluation.


Assuntos
Camellia sinensis/química , Mucoproteínas/química , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Chá/química , Proteínas de Plantas/química , Controle de Qualidade
9.
J Agric Food Chem ; 57(19): 9133-40, 2009 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-19761189

RESUMO

Mulberry is rich in alkaloids, polyphenols, flavonoids, and anthocyanins, which have been suggested to be responsible for health benefits. The concentrations of 1-deoxynojirimycin (DNJ), resveratrol, oxyresveratrol, cyanidin-3-O-beta-glucoside (Cy-3-glu), cyanidin-3-O-beta-rutinoside (Cy-3-rut), and rutin in mulberry juice, fruits, and leaves of 8 species grown in China were examined. It is the first time content determination of DNJ in mulberry juice and oxyresveratrol in mulberry fruits and leaves has been reported. Among the varieties tested, Da 10 (Morus atropurpurea Roxb.) was the most valuable cultivar considering its high content of functional components. Besides, Hetianbaisang (M. alba Linn.), Taiwanguosang (M. atropurpurea Roxb.), Fujian 2 hao (M. alba Linn.), Gaozhoujisang (M. australis Poir.), and Shanxiguosang (M. nigra Linn.) were rich in DNJ, resveratrol, oxyresveratrol, anthocyanins, and flavonoids, respectively. The high contents of functional compounds in mulberry juice, fruits, and leaves implied that they might be potential resources for the development of functional drinks and food.


Assuntos
1-Desoxinojirimicina/análise , Flavonoides/análise , Morus/química , Estilbenos/análise , Antocianinas/análise , Bebidas/análise , China , Cromatografia Líquida de Alta Pressão , Frutas/química , Glucosídeos/análise , Folhas de Planta/química , Resveratrol , Rutina/análise , Especificidade da Espécie
10.
ISME J ; 1(2): 156-62, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18043625

RESUMO

Direct research on gut microbiota for understanding its role as 'an important organ' in human individuals is difficult owing to its vast diversity and host specificity as well as ethical concerns. Transplantation of human gut microbiota into surrogate hosts can significantly facilitate the research of human gut ecology, metabolism and immunity but rodents-based model provides results with low relevance to humans. A new human flora-associated (HFA) piglet model was hereby established taking advantage of the high similarity between pigs and humans with respect to the anatomy, physiology and metabolism of the digestive system. Piglets were delivered via cesarean section into a SPF-level barrier system and were inoculated orally with a whole fecal suspension from one healthy 10-year-old boy. The establishment and composition of the intestinal microbiota of the HFA piglets were analyzed and compared with that of the human donor using enterobacterial repetitive intergenic consensus sequence-PCR fingerprinting-based community DNA hybridization, group-specific PCR-temperature gradient gel electrophoresis and real-time PCR. Molecular profiling demonstrated that transplantation of gut microbiota from a human to germfree piglets produced a donor-like microbial community with minimal individual variation. And the microbial succession with aging of those ex-germfree piglets was also similar to that observed in humans. This HFA model provides a significantly improved system for research on gut ecology in human metabolism, nutrition and drug discovery.


Assuntos
Trato Gastrointestinal/microbiologia , Modelos Animais , Animais , Animais Recém-Nascidos , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bacteroides/classificação , Bacteroides/genética , Bacteroides/isolamento & purificação , Bifidobacterium/classificação , Bifidobacterium/genética , Bifidobacterium/isolamento & purificação , Criança , Impressões Digitais de DNA/métodos , Eletroforese em Gel de Poliacrilamida , Vida Livre de Germes , Humanos , Masculino , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Especificidade da Espécie , Suínos
11.
Plant Foods Hum Nutr ; 61(2): 57-65, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16816988

RESUMO

Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China.


Assuntos
Citrus/química , Flavonoides/análise , China , Cromatografia Líquida de Alta Pressão/métodos , Citrus/classificação , Análise de Alimentos , Humanos , Medicina Tradicional Chinesa , Especificidade da Espécie
12.
Br J Nutr ; 96(1): 154-60, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16870004

RESUMO

The carotenoid zeaxanthin is concentrated within the macula. Increased macular zeaxanthin is suggested to lower the risk of age-related macular degeneration. The small red berry, wolfberry (Fructus barbarum L.; Gou Qi Zi and Kei Tze), is one of the richest natural sources of zeaxanthin. However, carotenoid bioavailability is low, and food-based products with enhanced bioavailability are of interest. The present study investigated zeaxanthin bioavailability from three wolfberry formulations. Berries were homogenised in hot (80 degrees C) water, warm (40 degrees C) skimmed milk and hot (80 degrees C) skimmed milk, with freeze drying of each preparation into a powdered form. A zeaxanthin-standardised dose (15 mg) of each was consumed, in randomised order, together with a standardised breakfast by twelve healthy, consenting subjects in a cross-over trial, with a 3-5-week washout period between treatments. Blood samples were taken via a venous cannula immediately before (fasting) and 2, 4, 6, 7, 8 and 10 h post-ingestion. Zeaxanthin concentration in the triacylglycerol-rich lipoprotein fraction of plasma was measured by HPLC. Results showed that triacylglycerol-rich lipoprotein zeaxanthin peaked at 6 h post-ingestion for all formulations. Zeaxanthin bioavailability from the hot milk formulation was significantly higher (P < 0.001) than from the others. Mean area under the curve (n 12) results were 9.73 (sem 2.45), 3.24 (sem 0.72) and 3.14 (sem 1.09) nmol x h/l for the hot milk, warm milk and hot water formulations, respectively. Results showed clearly that homogenisation of wolfberry in hot skimmed milk results in a formulation that has a 3-fold enhanced bioavailability of zeaxanthin compared with both the 'classical' hot water and warm skimmed milk treatment of the berries.


Assuntos
Suplementos Nutricionais , Medicamentos de Ervas Chinesas/administração & dosagem , Lycium , Leite , Xantofilas/farmacocinética , Adulto , Animais , Antineoplásicos Fitogênicos/sangue , Antineoplásicos Fitogênicos/farmacocinética , Área Sob a Curva , Disponibilidade Biológica , Estudos Cross-Over , Composição de Medicamentos/métodos , Feminino , Temperatura Alta , Humanos , Lipoproteínas/sangue , Masculino , Triglicerídeos/sangue , Água , Xantofilas/sangue , Zeaxantinas
13.
Planta ; 215(5): 754-62, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12244440

RESUMO

Aspartic proteinase (EC 3.4.23) activity plays a pivotal role in the degradation of Theobroma cacao L. seed proteins during the fermentation step of cacao bean processing. Therefore, this enzyme is believed to be critical for the formation of the peptide and amino acid cocoa flavor precursors that occurs during fermentation. Using cDNA cloning and northern blot analysis, we show here that there are at least two distinct aspartic proteinase genes ( TcAP1 and TcAP2) expressed during cacao seed development. Both genes are expressed early during seed development and their mRNA levels decrease towards the end of seed maturation. TcAP2 is expressed at a much higher level than TcAP1, although the expression of TcAP1 increases slightly during germination. The proteins encoded by TcAP1 and TcAP2 are relatively different from each other (73% identity). This, and the fact that the two corresponding genes have different expression patterns, suggests that the TcAP1 and TcAP2 proteins may have different functions in the maturing seeds and during germination. Because the TcAP2 gene is expressed at a much higher level during seed development than TcAP1, it is likely that the TcAP2 protein is primarily responsible for the majority of the industrially important protein hydrolysis that occurs during cacao bean fermentation. Finally, TcAP2 has been functionally expressed in the yeast Yarrowia lipolytica. The secreted recombinant protein is able to hydrolyse bovine haemoglobin at acidic pH and is sensitive to pepstatin A, confirming that TcAP2 encodes an aspartic proteinase, and strongly suggests that this gene encodes the well-characterized aspartic proteinase of mature cacao seeds.


Assuntos
Ácido Aspártico Endopeptidases/genética , Cacau/enzimologia , Leucina/análogos & derivados , Sementes/enzimologia , Sequência de Aminoácidos , Ácido Aspártico Endopeptidases/efeitos dos fármacos , Ácido Aspártico Endopeptidases/metabolismo , Cacau/genética , Clonagem Molecular , Cumarínicos/farmacologia , DNA Complementar/química , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Concentração de Íons de Hidrogênio , Isocumarinas , Isoenzimas/efeitos dos fármacos , Isoenzimas/genética , Isoenzimas/metabolismo , Leucina/farmacologia , Dados de Sequência Molecular , Pepstatinas/farmacologia , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sementes/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Yarrowia/genética , Yarrowia/metabolismo
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