1,721,119 research outputs found
Primary structure and glycan moiety characterization of PD-Ss, type 1 ribosome-inactivating proteins from Phytolacca dioica L. seeds, by precursor ion discovery on a Q-TOF mass spectrometer
No full textSeeds from Phytolacca dioica L. contain at least three N-glycosylated PD-Ss, type 1 ribosome-inactivating proteins (RIPs), which were separated and purified to homogeneity by conventional chromatographic techniques. ESI-Q-TOF mass spectrometry provided the accurate Mr of native PD-S1 and PD-S3 (30957.1 and 29785.1, respectively) and the major form PD-S2 (30753.8). As the amino acid sequence of PD-S2 was already known, its disulfide pairing was determined and found to be Cys34-Cys262 and Cys88-Cys110. Further structural characterization of PD-S1 and PD-S3 (N-terminal sequence determination up to residue 30, amino acid analysis and tryptic peptide mapping) showed that the three PD-Ss shared the entire protein sequence. To explain the different chromatographic behaviour, their glycosylation patterns were characterized by a fast and sensitive mass spectrometry-based approach, applying a precursor ion discovery mode on a Q-TOF mass spectrometer. A standard plant paucidomannosidic N-glycosylation pattern [Hex3, HexNAc2, deoxyhexose1, pentose1] was found for PD-S1 and PD-S2 on Asn120. Furthermore, a glycosylation site carrying only a HexNAc residue was identified on Asn112 in PD-S1 and PD-S3. Finally, considering the two disulfide bridges and the glycan moieties, the experimental Mr values were in agreement with the mass values calculated from the primary structure. The complete characterization of PD-Ss shows the high potential of mass spectrometry to rapidly characterize proteins, widespread in eukaryotes, differing only in their glycosylation motifs. © 2008 Elsevier Ltd. All rights reserved
A novel polygalacturonase-inhibiting protein (PGIP) from Lathyrus sativus L. seeds
No full textPolygalacturonase-inhibiting proteins (PGIPs) are extracellular plant proteins bound to the plant cell wall containing leucine-rich repeats (LRR). They play an important role in plant defence being able to inhibit fungal endopolygalacturonases (EPGs), the first enzymes secreted by phytopathogenic fungi during plant infection. In the present work, a novel PGIP (LsPGIP) has been isolated from Lathyrus sativus seeds. LsPGIP exhibited an inhibitory activity towards EPGs from Aspergillus niger and Rhizopus spp. A pI value of 8.3 and a molecular mass of 40 kDa were determined for the purified inhibitor. Furthermore, N-terminal sequence up to residue 20 revealed that LsPGIP exhibit a high percentage of identity with PGIP from Actinidia deliciosa. A secondary structure similar to those of other polygalacturonase inhibitors was also inferred form circular dichroism data. © 2012 Bentham Science Publishers
Peptide fingerprint of high quality Campania white wines by MALDI-TOF mass spectrometry
No full textFood traceability is essential to preserve the identity of unique quality traits against frauds or commercial disputes. Therefore, there is a growing demand of new traceability systems for the collection of information related to units/batches of food ingredients and products. A rapid method based on peptide profiles obtained from tryptic digests of whole wine proteins by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry is described. Reliable peptide fingerprints were obtained for high quality Campania white wines, providing a signature of the finished products. The MALDI spectra revealed the presence of common diagnostic ions, but also evidenced differences between wines. Furthermore, the MALDI-TOF spectral traces were converted into simulated images to obtain a graphical representation of spectra. The resulting "mass codes" constitute a simple tool to display differences between samples, suggesting their potential use as "biological bar codes" for food authenticity and traceability, probably applicable to other classes of certified food products. © 2008 Elsevier Ltd. All rights reserved
Biological activities of the antiviral protein BE27 from sugar beet (Beta vulgaris L.)
No full textThe ribosome inactivating protein BE27 displays several biological activities in vitro that could result in a broad action against several types of pathogens.Beetin 27 (BE27), a ribosome-inactivating protein (RIP) from sugar beet (Beta vulgaris L.) leaves, is an antiviral protein induced by virus and signaling compounds such as hydrogen peroxide and salicylic acid. Its role as a defense protein has been attributed to its RNA polynucleotide:adenosine glycosidase activity. Here we tested other putative activities of BE27 that could have a defensive role against pathogens finding that BE27 displays rRNA N-glycosidase activity against yeast and Agrobacterium tumefaciens ribosomes, DNA polynucleotide:adenosine glycosidase activity against herring sperm DNA, and magnesium-dependent endonuclease activity against the supercoiled plasmid PUC19 (nicking activity). The nicking activity could be a consequence of an unusual conformation of the BE27 active site, similar to that of PD-L1, a RIP from Phytolacca dioica L. leaves. Additionally, BE27 possesses superoxide dismutase activity, thus being able to produce the signal compound hydrogen peroxide. BE27 is also toxic to COLO 320 cells, inducing apoptosis in these cells by either activating the caspase pathways and/or inhibiting protein synthesis. The combined effect of these biological activities could result in a broad action against several types of pathogens such as virus, bacteria, fungi or insects
A new age for biomedical applications of Ribosome Inactivating Proteins (RIPs): from bioconjugate to nanoconstructs.
Full text linkRibosome-inactivating proteins (RIPs) are enzymes (3.2.2.22) that possess N-glycosilase activity that irreversibly inhibits protein synthesis. RIPs have been found in plants, fungi, algae, and bacteria; their biological role is still under investigation, even if it has been recognized their role in plant defence against predators and viruses. Nevertheless, several studies on these toxins have been performed to evaluate their applicability in the biomedical field making RIPs selectively toxic towards target cells. Indeed, these molecules are extensively used to produce chimeric biomolecules, such as immunotoxins or protein/peptides conjugates. However, to date, clinical use of most of these bioconiujates has been limited by toxicity and immunogenicity. More recently, material sciences have provided a wide range of nanomaterials to be used as excellent vehicles for toxin-delivery, since they are characterized by improved stability, solubility, and in vivo pharmacokinetics. This review discusses progresses in the development of RIPs bioconjugates, with particular attention to the recent use of nanomaterials, whose appropriate design opens up a broad range of different possibilities to the use of RIPs in novel therapeutic approaches in human diseases
Type 1 ribosome-inactivating proteins from the ombú tree (phytolacca dioica L.)
No full textThe toxicity of plant proteins, later identified as ribosome-inactivating proteins (RIPs), was described more than a century ago and their enzymatic activity was established more than 30 years ago. However, their physiological role and related biological activities are still uncertain. Therefore, despite the body of literature, research on RIPs is ongoing. This review deals with new RIPs being purified, sequenced, characterized, and cloned, and an increasing number of 3D-structures that are determined at high resolution. This is the case of the five type 1 RIPs (PD-S1-3, PD-L1/2, PD-L3/4, dioicin 1, and dioicin 2) from seeds and leaves of the ombú tree (Phytolacca dioica L.), native of the grassy pampas of Argentina. The data collected so far will contribute to our understanding of important issues of RIP research: (1) identifying structural determinants responsible for new enzymatic activities such as the DNA cleaving activity; (2) glycosylation and its influence on the catalytic and biological activities; (3) cellular localization of endogenous RIPs and their physiological role(s). © Springer-Verlag Berlin Heidelberg 2010
Analysis of carbohydrates and amino acids in vegetable waste waters by ion chromatography.
No full textThe bactericidal action on Escherichia coli of ZF-RNase-3 is triggered by the suicidal action of the bacterium OmpT protease
No full textZF-RNase-3 is one of the RNases from zebrafish (Danio rerio) with special (i.e. noncatalytic) properties. These include angiogenic and bactericidal activities. Given the interest of fish RNases as host-defense effectors, we studied the mechanism of the bactericidal action of ZF-RNase-3 on Escherichia coli as a model Gram-negative bacterium. The results obtained indicate that the bactericidal activity of ZF-RNase-3 is not lost when its catalytic RNase activity is obliterated. On the other hand, fully denatured ZF-RNase-3 conserves its bactericidal activity. When ZF-RNase-3 is added to E. coli cultures, it is cleaved at a specific Arg-Arg peptide bond, thus engendering two peptide fragments. The larger fragment (residues 31-124), produced by proteolysis and reduction of a disulfide, is recognized as the actual bactericidal agent. The protease responsible for the proteolytic attack has been identified with OmpT, an outer membrane E. coli omptin protease. However, the most remarkable result obtained in the present study is the finding that the microbicidal action of ZF-RNase-3 can be achieved only with the suicidal cooperation of the bacterium itself. © 2010 FEBS
Nutritional and metabolic profiling of the globe artichoke (cynara scolymus L. cv. capuanella heads) in province of caserta, Italy
No full textGlobe artichoke (Cynara scolymus L.) is a typical vegetable of the countries of the Mediterranean basin. It produces edible immature flower bud and his cultivation has a great economic importance in Italy, first world producer. In the recent years, local cultivars have been gradually replaced with the modern ones, mostly due to the increasing demand of early products for the large-scale retail trade. The valorization of local resources, such as specific cultivars useful in productive processes, may contrast this tendency. In this framework, the aim of this research is the nutritional and metabolic characterization of the Cynara scolymus L. cv Capuanella, a typical artichoke of the Campania Region. The nutritional profile (i.e. moisture content, dietary fiber, ash, total proteins, lipids and carbohydrates, total and free amino acids, fatty acid composition, folic acid, C vitamin, total phenolic compounds) of edible immature flower bud of globe artichoke cv Capuanella was determined and compared to the Italian artichoke nutritional profile reported in the National Institute of Research on Food and Nutrition (INRAN) tables. On a fresh weight basis, the Capuanella artichoke total protein content was higher in comparison with the INRAN tables (3.08 vs. 2.70g/100 g, respectively), whereas essential amino acids were lower in Capuanella with respect to the INRAN values (826.3 vs. 884 mg/100 g, respectively). Among the fatty acids of Capuanella artichoke, the most abundant were the essential n-6 linoleic (55.20 mg/100 g) and palmitic (34.80 mg/g) acids, representing about 72% of the total fatty acids. Ascorbic acid was 13.70 mg/100 g, while folic acid represents 17% of Recommended Dietary Allowance (65.00 μg/100 g). Phenolic compounds were found to be abundant in Capuanella artichoke (1878.21 mg/100 g); in particular, the chlorogenic acid (425.46 mg/100 g) represents about 23% of total phenolic compounds. Finally, as confirmed by the AFLP analysis, the Capuanella artichokes belong to the "Romanesco" group
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