Publications by authors named "Graziano Guella"

The evolution of volatile compounds in wine comprises several acid-catalyzed reactions, such as glycosides precursors' hydrolysis and rearrangements, and significantly contributes to its sensory qualities, even after prolonged aging. The aim of this work was to use a well-defined experimental design and to examine how terpenoids in Gewürztraminer wine change over time when subjected to different temperatures and pH levels over two weeks. A theoretically-based approach was used, involving the definition of a complete system of ordinary differential equations (ODE) with well-established boundary conditions (initial concentration of reactants/products), using Kinetiscope, a kinetic simulation software.

View Article and Find Full Text PDF

Lipoxygenases catalyze the peroxidation of poly-unsaturated fatty acid chains either free or esterified in membrane lipids. Vitis vinifera LoxA is transcriptionally induced at ripening onset and localizes at the inner chloroplast membrane where it is responsible for galactolipid regiospecific mono- and di-peroxidation. Here we present a kinetic and structural characterization of LoxA.

View Article and Find Full Text PDF

Bioplastics possess the potential to foster a sustainable circular plastic economy, but their end-of-life is still challenging. To sustainably overcome this problem, this work proposes the hydrothermal carbonization (HTC) of residual bioplastics as an alternative green path. The focus is on cellulose acetate - a bioplastic used for eyewear, cigarette filters and other applications - showing the proof of concept and the chemistry behind the conversion, including a reaction kinetics model.

View Article and Find Full Text PDF

In this work, we identified the trail pheromone of the ant Crematogaster scutellaris. We combined gas chromatography-mass spectrometry analysis of extracts from the hind tibia, the location of the respective glands, with automated trail following assays. The study found tridecan-2-ol to be the strongest discriminator between hind tibia and other body part extracts.

View Article and Find Full Text PDF

Background: Phospholipids are highly diverse molecules with pleiotropic biological roles, from membrane components and signaling molecules, whose composition can change in response to both endogenous and external stimuli. Recent lipidomic studies on edible bivalve mollusks were focused on lipid nutritional value and growth requirements. However, no data are available on phospholipid profiles during bivalve larval development.

View Article and Find Full Text PDF

The use of alternative solutions for pest management to replace pesticides in agriculture is of great interest. Proteinaceous complexes deriving from edible oyster mushrooms were recently proposed as environmentally friendly bioinsecticides. Such complexes, composed of ostreolysin A6 (OlyA6) and pleurotolysin B (PlyB), target invertebrate-specific membrane sphingolipids in insect's midgut, causing death through the formation of transmembrane pores.

View Article and Find Full Text PDF

The aim of this paper is to provide a detailed characterisation of grape lipidome. To achieve this objective, it starts by describing a pipeline implemented in R software to allow the semi-automatic annotation of the detected lipid species. It also provides an extensive description of the different properties of each molecule (such as retention time dependencies, mass accuracy, adduct formation and fragmentation patterns), which allowed the annotations to be made more accurately.

View Article and Find Full Text PDF

Heterotrich ciliates typically retain toxic substances in specialized ejectable organelles, called extrusomes, which are used in predator-prey interactions. In this study, we analysed the chemical defence strategy of the freshwater heterotrich ciliate against the predatory ciliate , and the microturbellarian flatworm . The results showed that is able to defend itself against these two predators by deploying a mix of bioactive sterols contained in its extrusomes.

View Article and Find Full Text PDF

Euplotin C is a sesquiterpene of marine origin endowed with significant anti-microbial and anti-tumor properties. Despite the promising functional profile, its progress as a novel drug candidate has failed so far, due to its scarce solubility and poor stability in aqueous media, such as biological fluids. Therefore, overcoming these limits is an intriguing challenge for the scientific community.

View Article and Find Full Text PDF
Article Synopsis
  • Pore-forming toxins, particularly actinoporins, are found in animal venoms, with a notable discovery of 27 unique actinoporin-like genes (termed mytiporins) in the sea mussel Mytilus galloprovincialis.
  • Mytiporin-1, one of the characterized mytiporins, shows different properties from the typical actinoporin fragaceatoxin C, including weaker pore-forming ability and forming hexameric pores instead of octameric ones.
  • The existence and variability of mytiporins suggest they may play a significant role in the mussel's physiology and could impact their digestive processes or immune responses, indicating a strong evolutionary pressure for their
View Article and Find Full Text PDF

Mycotoxin contamination of maize kernels by fungal pathogens like and is a chronic global challenge impacting food and feed security, health, and trade. Maize genes () synthetize oxylipins that play defense roles and govern host-fungal interactions. The current study investigated the involvement of in maize resistance against these two fungi.

View Article and Find Full Text PDF

(L.) is cultivated worldwide for its nutrient-rich nuts. In Italy, despite the growing demand, walnut cultivation has gone through a strong decline in recent decades, which led to Italy being among the top five net importing countries.

View Article and Find Full Text PDF

Periodontal disease is a chronic oral inflammatory disorder initiated by pathobiontic bacteria found in dental plaques-complex biofilms on the tooth surface. The disease begins as an acute local inflammation of the gingival tissue (gingivitis) and can progress to periodontitis, which eventually leads to the formation of periodontal pockets and ultimately results in tooth loss. The main problem in periodontology is that the diagnosis is based on the assessment of the already obvious tissue damage.

View Article and Find Full Text PDF

Ostreolysin A6 (OlyA6) is a 15 kDa protein produced by the oyster mushroom (). It belongs to the aegerolysin family of proteins and binds with high affinity to the insect-specific membrane sphingolipid, ceramide phosphoethanolamine (CPE). In concert with its partnering protein with the membrane-attack-complex/perforin domain, pleurotolysin B (PlyB), OlyA6 can form bicomponent 13-meric transmembrane pores in artificial and biological membranes containing the aegerolysin lipid receptor, CPE.

View Article and Find Full Text PDF

Iron-sulfur clusters are thought to be ancient cofactors that could have played a role in early protometabolic systems. Thus far, redox active, prebiotically plausible iron-sulfur clusters have always contained cysteine ligands to the cluster. However, extant iron-sulfur proteins can be found to exploit other modes of binding, including ligation by histidine residues, as seen with [2Fe-2S] Rieske and MitoNEET proteins.

View Article and Find Full Text PDF

Wet-dry cycles driven by heating to high temperatures are frequently invoked for the prebiotic synthesis of peptides. Similarly, iron-sulfur clusters are often cited as an example of an ancient catalyst that helped prune early chemical systems into metabolic-like pathways. Because extant iron-sulfur clusters are metallocofactors of protein enzymes and nearly ubiquitous across biology, a reasonable hypothesis is that prebiotic iron-sulfur peptides formed on the early Earth.

View Article and Find Full Text PDF

Cell-membrane fluidity is a fundamental parameter in cold resistance. It is regulated by a fine tuning of lipid composition, usually involving a great chemical diversity among head-groups, chain lengths, and degree of unsaturation. To give new insights on Alpine chironomid cold adaptation, we analysed the lipid membrane composition of Diamesa tonsa and Pseudodiamesa branickii, two species known to have different cold-tolerance, stronger in the former.

View Article and Find Full Text PDF

Ciliates are a rich source of molecules synthesized to socialize, compete ecologically, and interact with prey and predators. Their isolation from laboratory cultures is often straightforward, permitting the study of their mechanisms of action and their assessment for applied research. This review focuses on three classes of these bioactive molecules: (i) water-borne, cysteine-rich proteins that are used as signaling pheromones in self/nonself recognition phenomena; (ii) cell membrane-associated lipophilic terpenoids that are used in interspecies competitions for habitat colonization; (iii) cortical granule-associated molecules of various chemical nature that primarily serve offence/defense functions.

View Article and Find Full Text PDF

Lipids play many essential roles in living organisms, which accounts for the great diversity of these amphiphilic molecules within the individual lipid classes, while their composition depends on intrinsic and extrinsic factors. Recent developments in mass spectrometric methods have significantly contributed to the widespread application of the liquid chromatography-mass spectrometry (LC-MS) approach to the analysis of plant lipids. However, only a few investigators have studied the extensive composition of grape lipids.

View Article and Find Full Text PDF

Strain 3P27G6 was isolated from an artesian well connected to the thermal water basin of Comano Terme, Province of Trento, Italy. In phylogenetic analyses based on multilocus sequence analysis, strain 3P27G6 clustered together with WSM2073. Genome sequencing produced a 99.

View Article and Find Full Text PDF

Ostreolysin A6 (OlyA6) is a protein produced by the oyster mushroom (). It binds to membrane sphingomyelin/cholesterol domains, and together with its protein partner, pleurotolysin B (PlyB), it forms 13-meric transmembrane pore complexes. Further, OlyA6 binds 1000 times more strongly to the insect-specific membrane sphingolipid, ceramide phosphoethanolamine (CPE).

View Article and Find Full Text PDF

Several classes of flavonoids, such as anthocyanins, flavonols, flavanols, and flavones, undergo a slow H/D exchange on aromatic ring A, leading to full deuteration at positions C(6) and C(8). Within the flavanol class, H-C(6) and H-C(8) of catechin and epicatechin are slowly exchanged in DO to the corresponding deuterated analogues. Even quercetin, a relevant flavonol representative, shows the same behaviour in a DO/DMSOd 1:1 solution.

View Article and Find Full Text PDF

Proanthocyanidins are key metabolites that explain wine sensorial character (bitterness and astringency) and red wine color changes during aging. Therefore, a fast and accurate method to evaluate the degree of polymerization and the structural composition of the polymeric proanthocyanidins is a crucial analytical tool. Phloroglucinolysis is the most used method for this analysis but, unfortunately, the phloroglucinol adducts of the monomeric flavan-3-ols are not commercially available, making the results less accurate.

View Article and Find Full Text PDF

A vast portion of the mammalian genome is transcribed as long non-coding RNAs (lncRNAs) acting in the cytoplasm with largely unknown functions. Surprisingly, lncRNAs have been shown to interact with ribosomes, encode peptides, or act as ribosome sponges. These functions still remain mostly undetected and understudied owing to the lack of efficient tools for genome-wide simultaneous identification of ribosome-associated and peptide-producing lncRNAs.

View Article and Find Full Text PDF

Recent computational advancements in the simulation of biochemical processes allow investigating the mechanisms involved in protein regulation with realistic physics-based models, at an atomistic level of resolution. These techniques allowed us to design a drug discovery approach, named Pharmacological Protein Inactivation by Folding Intermediate Targeting (PPI-FIT), based on the rationale of negatively regulating protein levels by targeting folding intermediates. Here, PPI-FIT was tested for the first time on the cellular prion protein (PrP), a cell surface glycoprotein playing a key role in fatal and transmissible neurodegenerative pathologies known as prion diseases.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Notice

Message: fwrite(): Write of 34 bytes failed with errno=28 No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 272

Backtrace:

A PHP Error was encountered

Severity: Warning

Message: session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)

Filename: Unknown

Line Number: 0

Backtrace: