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1.
J Agric Food Chem ; 67(37): 10423-10431, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31487168

RESUMO

Plants often produce antifungal peptides and proteins in response to infection. Also wheat, which is the main ingredient of bread dough, contains such components. Here, we show that while some industrial strains of the baker's yeast Saccharomyces cerevisiae can efficiently ferment dough, some other strains show much lower fermentation capacities because they are sensitive to a specific wheat protein. We purified and identified what turned out to be a thaumatin-like protein through a combination of activity-guided fractionation, cation exchange chromatography, reversed-phase HPLC, and LC-MS/MS. Recombinant expression of the corresponding gene and testing the activity confirmed the inhibitory activity of the protein.


Assuntos
Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Triticum/química , Cromatografia Líquida , Fermentação , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/metabolismo , Espectrometria de Massas em Tandem , Triticum/genética , Triticum/metabolismo , Triticum/microbiologia
2.
J Agric Food Chem ; 67(33): 9241-9253, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31369258

RESUMO

Antiviral compounds targeting viral replicative processes have been studied as an alternative for the control of begomoviruses. Previously, we have reported that the peptide AmPep1 has strong affinity binding to the replication origin sequence of tomato yellow leaf curl virus (TYLCV). In this study, we describe the mechanism of action of this peptide as a novel alternative for control of plant-infecting DNA viruses. When AmPep1 was applied exogenously to tomato and Nicotiana benthamiana plants infected with TYLCV, a decrease in the synthesis of the two viral DNA strands (CS and VS) was observed, with a consequent delay in the development of disease progress in treated plants. The chemical mechanism of action of AmPep1 was deduced using Raman spectroscopy and molecular modeling showing the formation of chemical interactions such as H bonds and electrostatic interactions and the formation of π-π interactions between both biomolecules contributing to tampering with the viral replication.


Assuntos
Amaranthus/química , Antivirais/química , Antivirais/farmacologia , Begomovirus/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , RNA Viral/química , Replicação Viral/efeitos dos fármacos , Begomovirus/química , Begomovirus/genética , Begomovirus/fisiologia , Sequências Repetidas Invertidas/efeitos dos fármacos , Lycopersicon esculentum/virologia , Doenças das Plantas/virologia , Proteínas de Plantas/química , RNA Viral/genética , Tabaco/virologia
3.
BMC Plant Biol ; 19(1): 347, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395025

RESUMO

BACKGROUND: Flavonoid 3'-hydroxlase (F3'H) is an important enzyme in determining the B-ring hydroxylation pattern of flavonoids. In monocots, previous studies indicated the presence of two groups of F3'Hs with different enzyme activities. One F3'H in rice was found to display novel chrysoeriol-specific 5'-hydroxylase activity. However, the evolutionary history of monocot F3'Hs and the molecular basis for the observed catalytic difference remained elusive. RESULTS: We performed genome-wide survey of 12 common monocot plants, and identified a total of 44 putative F3'H genes. The results showed that F3'H gene family had underwent volatile lineage-specific gene duplication and gene loss events in monocots. The expansion of F3'H gene family was mainly attributed to dispersed gene duplication. Phylogenetic analyses showed that monocot F3'Hs have evolved into two independent lineages (Class I and Class II) after gene duplication in the common ancestor of monocot plants. Evolutionary dynamics analyses had detected positive natural selection in Class II F3'Hs, acting on 7 specific amino acid sites. Protein modelling showed these selected sites were mainly located in the catalytic cavity of F3'H. Sequence alignment revealed that Class I and Class II F3'Hs displayed amino acid substitutions at two critical sites previously found to be responsible for F3'H and flavonoid 3'5'-hydroxylase (F3'5'H) activities. In addition, transcriptional divergence was also observed for Class I and Class II F3'Hs in four monocot species. CONCLUSIONS: We concluded that monocot F3'Hs have evolved into two independent lineages (Mono_F3'H Class I and Class II), after gene duplication during the common ancestor of monocot plants. The functional divergence of monocot F3'H Class II has been affected by positive natural selection, which acted on specific amino acid sites only. Critical amino acid sites have been identified to have high possibility to affect the substrate specificity of Class II F3'Hs. Our study provided an evolutionary and protein structural explanation to the previously observed chrysoeriol-specific 5'-hydroxylation activity for CYP75B4 in rice, which may also be true for other Class II F3'Hs in monocots. Our study presented clear evidence of plant-environmental interaction at the gene evolutionary level, and would guide future functional characterization of F3'Hs in cereal plants.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Grão Comestível/genética , Proteínas de Plantas/genética , Sistema Enzimático do Citocromo P-450/química , Grão Comestível/enzimologia , Evolução Molecular , Duplicação Gênica , Modelos Moleculares , Filogenia , Proteínas de Plantas/química , Seleção Genética , Alinhamento de Sequência
4.
J Agric Food Chem ; 67(37): 10401-10411, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31441654

RESUMO

This research applied inhibitors to reduce the content of cooked off-flavor components (dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, and 3-(methylthio)propanaldehyde) in heat-treated melon juice. The effects of glucose oxidase (GOD) on the formation and release of these four volatile sulfur compounds were also investigated. Results showed that GOD strongly inhibited the formation of the four compounds. In GOD-treated melon juice, S-methylmethionine was strongly protonated and not easily degraded into dimethyl sulfide. Moreover, the release of the dimethyl sulfide that did form was restrained by the hydrophobic interactions of gluconic acid and oxidation by hydrogen peroxide. In addition, gluconic acid (or glucose) and hydrogen peroxide could form a stable complex with methionine in an acidic matrix and thus prevented the methionine from producing 3-(methylthio)propanaldehyde, dimethyl disulfide, and dimethyl trisulfide by the Maillard reaction during heat processing.


Assuntos
Cucurbitaceae/química , Aromatizantes/química , Sucos de Frutas e Vegetais/análise , Culinária , Cucurbitaceae/enzimologia , Frutas/química , Frutas/enzimologia , Glucose Oxidase/química , Temperatura Alta , Humanos , Reação de Maillard , Odorantes/análise , Proteínas de Plantas/química , Compostos de Enxofre/química , Paladar
5.
J Agric Food Chem ; 67(38): 10713-10725, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31453702

RESUMO

Converting peanut protein biomass waste into environmentally friendly meat substitutes by a high-moisture extrusion process can help solve both resource and waste problems and be "double green". A multiscale method combined with some emerging techniques such as atomic force microscopy-based infrared spectroscopy and X-ray microscopy was used to make the whole extrusion process visible to show the process of forming a meat-like fibrous structure using two-dimensional and three-dimensional perspectives. The results showed that the protein molecules underwent dramatic structural changes and unfolded in the extruder barrel, which created favorable conditions for molecular rearrangement in the subsequent zones. It was confirmed that the meat-like fibrous structure started to form at the junction of the die and the cooling zone and that this structure was caused by the phase separation and rearrangement of protein molecules in the cooling zone. Moreover, the interactions between hydrogen bonds and disulfide bonds formed in the cooling zone maintained the meat-like fibrous structure with an α-helix > ß-sheet > ß-turn > random coil. Of the two main peanut proteins, arachin played a greater role in forming the fibrous structure than conarachin, especially those subunits of arachin with a molecular weight of 42, 39, and 22 kDa.


Assuntos
Arachis/química , Aromatizantes/química , Extratos Vegetais/química , Proteínas de Plantas/química , Resíduos/análise , Aromatizantes/isolamento & purificação , Química Verde , Ligações de Hidrogênio , Raios Infravermelhos , Extratos Vegetais/isolamento & purificação , Conformação Proteica
6.
J Agric Food Chem ; 67(37): 10296-10305, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31464437

RESUMO

Grass pea is an orphan legume that is grown in many places in the world. It is a high-protein, drought-tolerant legume that is capable of surviving extreme environmental challenges and can be a sole food source during famine. However, grass pea produces the neurotoxin ß-N-oxalyl-L-α,ß-diaminopropionic acid (ß-ODAP), which can cause a neurological disease. This crop is promising as a food source for both animals and humans if ß-ODAP levels and other antinutritional factors such as protease inhibitors are lowered or removed. To understand more about these proteins, a proteomic analysis of grass pea was conducted using three different extraction methods to determine which was more efficient at isolating antinutritional factors. Seed proteins extracted with Tris-buffered saline (TBS), 30% ethanol, and 50% isopropanol were identified by mass spectrometry, resulting in the documentation of the most abundant proteins for each extraction method. Mass spectrometry spectral data and BLAST2GO analysis led to the identification of 1376 proteins from all extraction methods. The molecular function of the extracted proteins revealed distinctly different protein functional profiles. The majority of the TBS-extracted proteins were annotated with nutrient reservoir activity, while the isopropanol extraction yielded the highest percentage of endopeptidase proteinase inhibitors. Our results demonstrate that the 50% isopropanol extraction method was the most efficient at isolating antinutritional factors including protease inhibitors.


Assuntos
Fracionamento Químico/métodos , Fabaceae/química , Extratos Vegetais/isolamento & purificação , Inibidores de Proteases/isolamento & purificação , Sementes/química , Endopeptidases/química , Fabaceae/genética , Fabaceae/metabolismo , Espectrometria de Massas , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Proteômica , Sementes/genética , Sementes/metabolismo
7.
Food Chem ; 298: 125023, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260964

RESUMO

This research investigated the effect of pH on forming electrostatic complexes between lentil protein isolate (LPI) and a range of anionic polysaccharides [carboxymethyl cellulose (CMC), gum Arabic (GA), alginate (AL), and ι-carrageenan (CAR)] at 4:1 LPI-polysaccharide mixing ratio, and their resulting emulsifying abilities. Maximum optical densities were found to be 0.486, 0.716, 0.310, and 0.190 for LPI-CMC, LPI-GA, LPI-AL, and LPI-CAR, respectively indicating the level of aggregate size and growth. LPI-CAR emulsion displayed the highest emulsion stability (ES) because of its higher continuous phase and emulsion viscosities, lower mean droplet sizes, and negatively charged droplets. They also formed much smaller complexes within solution due to their high negative charge. All other LPI-polysaccharide systems formed less stable emulsions than LPI alone due to the larger sizes of both complexes and oil droplets.


Assuntos
Ânions/química , Lens (Planta)/química , Proteínas de Plantas/química , Polissacarídeos/química , Alginatos/química , Carboximetilcelulose Sódica/química , Carragenina/química , Emulsões , Goma Arábica/química
8.
BMC Plant Biol ; 19(1): 287, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262258

RESUMO

BACKGROUND: The majority of apricot (Prunus armeniaca L.) cultivars display orange or yellow background skin, whereas some cultivars are particularly preferred by consumers because of their red blushed skin on the background. RESULTS: In this study, two blushed ('Jianali' and 'Hongyu') and two nonblushed ('Baixing' and 'Luntaixiaobaixing') cultivars were used to investigate the formation mechanism of blushed skin in apricots. High-performance liquid chromatography (HPLC) analysis showed that the blushed cultivars accumulated higher cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and peonidin-3-O-rutinoside levels during fruit ripening than the nonblushed cultivars. Based on coexpression network analysis (WGCNA), a putative anthocyanin-related R2R3-MYB, PaMYB10, and seven structural genes were identified from transcriptome data. The phylogenetic analysis indicated that PaMYB10 clustered in the anthocyanin-related MYB clade. Sequence alignments revealed that PaMYB10 contained a bHLH-interaction motif ([DE]Lx2[RK]x3Lx6Lx3R) and an ANDV motif. Subcellular localization analysis showed that PaMYB10 was a nuclear protein. Real-time qRT-PCR analysis demonstrated that the transcript levels of PaMYB10 and seven genes responsible for anthocyanin synthesis were significantly higher in blushed than in nonblushed apricots, which was consistent with the accumulation of anthocyanin. In addition, bagging significantly inhibited the transcript levels of PaMYB10 and the structural genes in 'Jianali' and blocked the red coloration and anthocyanin accumulation. Transient PaMYB10 overexpression in 'Luntaixiaobaixing' fruits resulted in the red blushed skin at the maturation stage. CONCLUSIONS: Taken together, these data reveal that three anthocyanins are responsible for the blushed skin of apricots, identify PaMYB10 as a positive regulator of anthocyanin biosynthesis in apricots, and demonstrate that blush formation depends on light.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Pigmentos Biológicos/biossíntese , Proteínas de Plantas/genética , Prunus armeniaca/fisiologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , Antocianinas/genética , Cromatografia Líquida de Alta Pressão , Cor , Frutas/genética , Frutas/fisiologia , Glucosídeos/biossíntese , Glucosídeos/genética , Filogenia , Pigmentos Biológicos/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Prunus armeniaca/genética , Alinhamento de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
9.
J Agric Food Chem ; 67(31): 8441-8451, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31339045

RESUMO

The increase in the atmospheric CO2 concentration is predicted to influence wheat production and grain quality and nutritional properties. In the present study, durum wheat (Triticum durum Desf. cv. Sula) was grown under two different CO2 (400 versus 700 µmol mol-1) concentrations to examine effects on the crop yield and grain quality at different phenological stages (from grain filling to maturity). Exposure to elevated CO2 significantly increased aboveground biomass and grain yield components. Growth at elevated CO2 diminished the elemental N content as well as protein and free amino acids, with a typical decrease in glutamine, which is the most represented amino acid in grain proteins. Such a general decrease in nitrogenous compounds was associated with altered kinetics of protein accumulation, N remobilization, and N partitioning. Our results highlight important modifications of grain metabolism that have implications for its nutritional quality.


Assuntos
Dióxido de Carbono/metabolismo , Sementes/crescimento & desenvolvimento , Triticum/metabolismo , Aminoácidos/química , Aminoácidos/metabolismo , Dióxido de Carbono/análise , Cinética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Sementes/química , Sementes/metabolismo , Triticum/química , Triticum/crescimento & desenvolvimento
10.
Plant Sci ; 286: 17-27, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300138

RESUMO

The plant-specific gibberellic acid (GA)-stimulated transcript gene family is critical for plant growth and development. There are 10 family members in rice (Oryza sativa), known as OsGASRs. However, few have been functionally characterized. Here, we investigated the function of OsGASR9 in rice. OsGASR9 transcripts were detected in various tissues, with the lowest and highest levels in leaves and panicles, respectively. Greater mRNA levels accumulated in young, compared with in old, panicles and spikelets. OsGASR9 localized to the plasma membrane, cytoplasm and nucleus. Transgenic RNA interference-derived lines in the Zhonghua 11 background exhibited reduced plant height, grain size and yield compared with the wild-type. The two osgasr9 mutants in the Nipponbare background showed similar phenotypes. Conversely, the overexpression of OsGASR9 in the two backgrounds increased plant height and grain size. A significantly increased grain yield per plant was also observed in the overexpression lines having a Nipponbare background. Furthermore, by measuring the GA-induced lengths of the second leaf sheaths and α-amylase activity levels of seeds, we concluded that OsGASR9 is a positive regulator of responses to GA in rice. Thus, OsGASR9 may regulate plant height, grain size and yield through the GA pathway and could have an application value in breeding.


Assuntos
Giberelinas/metabolismo , Oryza/genética , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Família Multigênica , Oryza/crescimento & desenvolvimento , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Interferência de RNA
11.
Plant Sci ; 286: 68-77, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300143

RESUMO

Apple (Malus domestica) is an important fruit worldwide; however, the development of the apple industry is limited by fungal disease. Apple bitter rot caused by the pathogen Colletotrichum gloeosporioides is one of the most devastating apple diseases, leading to large-scale losses in apple quality and production. WRKY transcription factors have important functions in the regulation of biotic and abiotic stresses. However, their biological and molecular functions in non-model plants, including apple, remain poorly understood. Here, we isolated MdWRKY100 from 'Hanfu' apple. The MdWRKY100 protein fused to green fluorescent protein localized to the nucleus, and MdWRKY100 in yeast cells displayed transcriptional activation activity, which is consistent with the function of a transcription factor. Additionally, several putative cis-acting elements involved in abiotic stress responsiveness were also identified in the MdWRKY100 promoter. Transcriptional analysis revealed that MdWRKY100 was expressed ubiquitously in all examined apple organs. Overexpression in apple increased resistance to Colletotrichum gloeosporioides, while RNAi silencing transgenic plants were more sensitive to Colletotrichum gloeosporioides. Collectively, our data demonstrate that MdWRKY100 is a positive regulator of Colletotrichum gloeosporioides resistance in apple.


Assuntos
Colletotrichum/fisiologia , Resistência à Doença/genética , Malus/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Malus/metabolismo , Malus/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Alinhamento de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
12.
J Agric Food Chem ; 67(33): 9354-9361, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31339706

RESUMO

As a popular ingredient for western and traditional Chinese medicine, the root and rhizome of Chinese licorice (Glycyrrhiza uralensis Fisch.) is often administered in the form of a decoction. The protein nanoparticles (NPs) self-assembled during the process of decoction. A major constitutive protein (GLP) was purified and determined to have a molecular weight of 28 kDa with an N-terminal sequence of NPDGL IACYC GQYCW. Over 80% of the purified GLP self-assembled into spherical NPs with diameters of 74.1 ± 0.7 nm and ζ-potential of -24.3 ± 1.7 mV when boiled in Tris-HCl buffer (pH = 7.9, 20 mM) at 100 °C for 60 min. Each nanoparticle was estimated by the SEC-MALLS approach to be composed of approximately 23 protein molecules. The NPs and GLP showed low cellular toxicity upon four types of cells including MDCK, L-02, HepG2, and Caco2 cells, while the NPs promoted proliferation of normal hepatocytes by 67%. The NPs solubilized the insoluble astragaloside IV by encapsulation. The results suggest a great potential for GLP-NPs as a promising prototype of a type of drug vehicle, a novel source of bioactive nanomaterials from herbal proteins, as well as a new mode of function with herbal components.


Assuntos
Glycyrrhiza/química , Nanopartículas/química , Extratos Vegetais/química , Proteínas de Plantas/química , Células CACO-2 , Proliferação de Células/efeitos dos fármacos , Células Hep G2 , Temperatura Alta , Humanos , Peso Molecular , Nanoestruturas/química , Extratos Vegetais/farmacologia , Proteínas de Plantas/farmacologia , Raízes de Plantas/química
13.
J Agric Food Chem ; 67(33): 9254-9264, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31356740

RESUMO

In continuation of our search for potent protoporphyrinogen IX oxidase (PPO, EC 1.3.3.4) inhibitors, we designed and synthesized a series of novel herbicidal cycloalka[d]quinazoline-2,4-dione-benzoxazinones. The bioassay results of these synthesized compounds indicated that most of the compounds exhibited very strong Nicotiana tabacum PPO (NtPPO) inhibition activity. More than half of the 37 synthesized compounds displayed over 80% control of all three tested broadleaf weeds at 37.5-150 g ai/ha by postemergent application, and a majority of them showed no phytotoxicity toward at least one kind of crop at 150 g ai/ha. Promisingly, 17i (Ki = 6.7 nM) was 6 and 4 times more potent than flumioxazin (Ki = 46 nM) and trifludimoxazin (Ki = 31 nM), respectively. Moreover, 17i displayed excellent, broad-spectrum herbicidal activity, even at levels as low as 37.5 g ai/ha, and it was determined to be safe for wheat at 150 g ai/ha in postemergent application, indicating the great potential for 17i development as a herbicide for weed control in wheat fields.


Assuntos
Benzoxazinas/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Herbicidas/química , Herbicidas/farmacologia , Proteínas de Plantas/antagonistas & inibidores , Protoporfirinogênio Oxidase/antagonistas & inibidores , Quinazolinas/química , Benzoxazinas/farmacologia , Desenho de Drogas , Cinética , Proteínas de Plantas/química , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Protoporfirinogênio Oxidase/química , Relação Quantitativa Estrutura-Atividade , Quinazolinas/farmacologia , Tabaco/efeitos dos fármacos , Tabaco/enzimologia , Controle de Plantas Daninhas
14.
J Agric Food Chem ; 67(29): 8119-8129, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31265283

RESUMO

Grass pea (Lathyrus sativus L.) is an important legume commonly grown in arid and semi-arid regions. This protein-rich legume performs well even under harsh environmental conditions and is considered to be a strategic famine food in developing countries. Unfortunately, its potential usage is greatly limited as a result of the presence of antinutritional factors, including the neuroexcitatory amino acid ß-N-oxalyl-l-α,ß-diaminopropionic acid (ß-ODAP) and protease inhibitors. ß-ODAP is responsible for a neurodegenerative syndrome that results in the paralysis of lower limbs, while protease inhibitors affect protein digestibility, resulting in reduced growth. Concerted research efforts have led to development of grass pea cultivars with reduced ß-ODAP content. In contrast, very little information is available on the protease inhibitors of L. sativus. In this study, we have conducted biochemical characterization of 51 L. sativus accessions originating from different geographical regions. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses of seed globulins and prolamins revealed striking similarity in their protein profile, although geographic-specific variations in profiles was also evident. Measurement of Bowman-Birk chymotrypsin inhibitor (BBi) and Kunitz trypsin inhibitor (KTi) activities in accessions revealed striking differences among them. Amino acid sequence alignment of grass pea BBi and KTi revealed significant homology to protease inhibitors from several legumes. Real-time polymerase chain reaction analysis demonstrated high-level expression of BBi and KTi in dry seeds and weak expression in other organs. Our study demonstrates substantial variation in BBi and KTi among grass pea accessions that could be exploited in breeding programs for the development of grass pea lines that are devoid of these antinutritional factors.


Assuntos
Lathyrus/química , Proteínas de Plantas/química , Inibidor da Tripsina de Soja de Bowman-Birk/química , Sequência de Aminoácidos , Geografia , Lathyrus/genética , Lathyrus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Alinhamento de Sequência , Inibidor da Tripsina de Soja de Bowman-Birk/genética , Inibidor da Tripsina de Soja de Bowman-Birk/isolamento & purificação , Inibidor da Tripsina de Soja de Bowman-Birk/metabolismo
15.
J Agric Food Chem ; 67(29): 8197-8204, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31287317

RESUMO

Potato pectin contains some proteinaceous components and exhibits emulsifying and emulsion stabilizing abilities. The objective of this study was to elucidate the effect of the pectin moiety of the pectin-protein conjugate present in pectic extracts from potato tubers on their interfacial properties. Potato pectin was extracted from highly purified cell wall materials to avoid the contamination of unconjugated proteins. The abilities of the potato pectin to adsorb to graphite surfaces and to resist surfactant-induced competitive displacement from the air-water interface were investigated using atomic force microscopy. The pectin moiety of the potato pectin was capable of adsorbing to graphite surfaces even after alkali treatment. Furthermore, the potato pectin exhibited enhanced resistance to surfactant-induced competitive displacement from the interface as a result of the formation of network structures of self-assembled pectin moieties at the interface. The present results suggest the importance of the pectin moiety with regard to the interfacial properties of potato pectin.


Assuntos
Pectinas/química , Extratos Vegetais/química , Proteínas de Plantas/química , Solanum tuberosum/química , Tensoativos/química , Ar/análise , Tubérculos/química , Água/química
16.
J Agric Food Chem ; 67(28): 7810-7820, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31264418

RESUMO

Antihypertensive peptides were screened from thermolysin hydrolysate of Cassia obtusifolia seeds (Jue Ming Zi) using two independent bioassay-guided fractionations, reversed-phase high-performance liquid chromatography (RP-HPLC), and strong cation-exchange (SCX) liquid chromatography coupled with angiotensin I-converting enzyme (ACE) inhibitory assay. The identical peptide in the most active RP-HPLC and SCX fractions was simultaneously de novo sequenced as FHAPWK with high-resolution mass spectrometry. FHAPWK (IC50 = 16.83 ± 0.90 µM) was further identified as a competitive inhibitor and a true inhibitor on ACE by a Lineweaver-Burk plot and preincubation experiment, respectively. The molecular docking simulation indicated that FHAPWK could interact with several key residues of the ACE active site, which is consistent with the result of the inhibitory kinetics study. Moreover, its antihypertensive effect was demonstrated using the animal model of spontaneously hypertensive rats. It is concluded that FHAPWK is the first reported antihypertensive peptide derived from thermolysin hydrolysate of C. obtusifolia seeds.


Assuntos
Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/química , Cassia/química , Hipertensão/tratamento farmacológico , Peptídeos/administração & dosagem , Peptídeos/química , Proteínas de Plantas/química , Animais , Descoberta de Drogas , Humanos , Masculino , Espectrometria de Massas , Simulação de Acoplamento Molecular , Ratos , Ratos Endogâmicos SHR , Sementes/química
17.
J Agric Food Chem ; 67(28): 7898-7907, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282664

RESUMO

This study aimed to explore the effects of silencing HB12 and TT8 genes on protein utilization characteristics of alfalfa. Ground samples of 11 HB12-silenced (HB12i), 5 TT8-silenced (TT8i) and 4 wild type (WT) were incubated in a Daisy II incubator with N15 labeled ammonium sulfate for 0, 4, 8, 12, and 24 h. CP degradation and degradational kinetics, microbial nitrogen fractions, and protein metabolic profiles were determined. Moreover, relationships between protein profiles and FTIR spectral parameters were estimated. Results showed that transgenic alfalfa had lower CP degradation, microbial protein, and total available protein compared with WT, especially for HB12i. In addition, CP degradation and protein metabolic profiles were closely correlated with FTIR spectral parameters and thereby could be predicted from spectral parameters. In conclusion, silencing of HB12 and TT8 genes in alfalfa decreased protein degradational and metabolic profiles, which were predictable with FTIR spectral parameters.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Inativação Gênica , Proteínas de Homeodomínio/genética , Medicago sativa/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Rúmen/metabolismo , Ração Animal/análise , Animais , Bactérias/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Bovinos , Digestão , Proteínas de Homeodomínio/metabolismo , Cinética , Medicago sativa/química , Medicago sativa/metabolismo , Proteínas de Plantas/química , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteólise , Rúmen/química , Rúmen/microbiologia
18.
BMC Plant Biol ; 19(1): 316, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307394

RESUMO

BACKGROUND: HKT channels mediate sodium uniport or sodium and potassium symport in plants. Monocotyledons express a higher number of HKT proteins than dicotyledons, and it is only within this clade of HKT channels that cation symport mechanisms are found. The prevailing ion composition in the extracellular medium affects the transport abilities of various HKT channels by changing their selectivity or ion transport rates. How this mutual effect is achieved at the molecular level is still unknown. Here, we built a homology model of the monocotyledonous OsHKT2;2, which shows sodium and potassium symport activity. We performed molecular dynamics simulations in the presence of sodium and potassium ions to investigate the mutual effect of cation species. RESULTS: By analyzing ion-protein interactions, we identified a cation coordination site on the extracellular protein surface, which is formed by residues P71, D75, D501 and K504. Proline and the two aspartate residues coordinate cations, while K504 forms salt bridges with D75 and D501 and may be involved in the forwarding of cations towards the pore entrance. Functional validation via electrophysiological experiments confirmed the biological relevance of the predicted ion coordination site and identified K504 as a central key residue. Mutation of the cation coordinating residues affected the functionality of HKT only slightly. Additional in silico mutants and simulations of K504 supported experimental results. CONCLUSION: We identified an extracellular cation coordination site, which is involved in ion coordination and influences the conduction of OsHKT2;2. This finding proposes a new viewpoint in the discussion of how the mutual effect of variable ion species may be achieved in HKT channels.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Transporte de Íons , Proteínas de Plantas/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Animais , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/genética , Cátions/metabolismo , Clonagem Molecular , Eletrofisiologia , Mutação , Proteínas de Plantas/química , Proteínas de Plantas/genética , Conformação Proteica , Relação Estrutura-Atividade , Xenopus laevis
19.
BMC Plant Biol ; 19(1): 310, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307401

RESUMO

BACKGROUND: The hypersensitive defense response (HR) in plants is a fast, localized necrotic response around the point of pathogen ingress. HR is usually triggered by a pathogen recognition event mediated by a nucleotide-binding site, leucine-rich repeat (NLR) protein. The autoactive maize NLR gene Rp1-D21 confers a spontaneous HR response in the absence of pathogen recognition. Previous work identified a set of loci associated with variation in the strength of Rp1-D21-induced HR. A polygalacturonase gene homolog, here termed ZmPGH1, was identified as a possible causal gene at one of these loci on chromosome 7. RESULTS: Expression of ZmPGH1 inhibited the HR-inducing activity of both Rp1-D21 and that of another autoactive NLR, RPM1(D505V), in a Nicotiana benthamiana transient expression assay system. Overexpression of ZmPGH1 in a transposon insertion line of maize was associated with suppression of chemically-induced programmed cell death and with suppression of HR induced by Rp1-D21 in maize plants grown in the field. CONCLUSIONS: ZmPGH1 functions as a suppressor of programmed cell death induced by at least two autoactive NLR proteins and by two chemical inducers. These findings deepen our understanding of the control of the HR in plants.


Assuntos
Apoptose/fisiologia , Proteínas de Plantas/fisiologia , Poligalacturonase/fisiologia , Zea mays/fisiologia , Apoptose/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Genes de Plantas , Leucina , Proteínas de Plantas/química , Proteínas de Plantas/genética , Poligalacturonase/química , Poligalacturonase/genética , Recombinação Genética , Sequências Repetitivas de Aminoácidos , Tabaco/genética , Zea mays/enzimologia , Zea mays/genética , Zea mays/imunologia
20.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1799-1807, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342705

RESUMO

Chalcone synthase( CHS) and chalcone isomerase( CHI) are key enzymes in the biosynthesis pathway of flavonoids. In this study,unigenes for CHS and CHI were screened from the transcriptome database of Arisaema heterophyllum. The open reading frame( ORFs) of chalcone synthase( Ah CHS) and chalcone isomerase( Ah CHI) were cloned from the plant by RT-PCR. The physicochemical properties,expression and structure characteristics of the encoded proteins Ah CHS and Ah CHI were analyzed. The ORFs of Ah CHS and Ah CHI were 1 176,630 bp in length and encoded 392,209 amino acids,respectively. Ah CHS functioned as a symmetric homodimer. The N-terminal helix of one monomer entwined with the corresponding helix of another monomer. Each CHS monomer consisted of two structural domains. In particular,four conserved residues define the active site. The tertiary structure of Ah CHI revealed a novel open-faced ß-sandwich fold. A large ß-sheet( ß4-ß11) and a layer of α-helices( α1-α7) comprised the core structure. The residues spanning ß4,ß5,α4,and α6 in the three-dimensional structure were conserved among CHIs from different species. Notably,these structural elements formed the active site on the protein surface,and the topology of the active-site cleft defined the stereochemistry of the cyclization reaction. The homology comparison showed that Ah CHS had the highest similarity to the CHS of Anthurium andraeanum,while Ah CHI had the highest similarity to the CHI of Paeonia delavayi. This study provided the basis for the functional study of Ah CHS and Ah CHI and the further study on plant flavonoid biosynthesis pathway.


Assuntos
Aciltransferases/genética , Arisaema/enzimologia , Liases Intramoleculares/genética , Proteínas de Plantas/genética , Aciltransferases/química , Arisaema/genética , Clonagem Molecular , Liases Intramoleculares/química , Proteínas de Plantas/química
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