the allergen mus m 1 0102 cysteine residues and molecular allergology

Abstract Mus m 1.0102 is a member of the mouse Major Urinary Protein family, belonging to the Lipocalins superfamily. Major Urinary Proteins (MUPs) are characterized by highly conserved structural motifs. These include a disulphide bond, involved in protein oxidative folding and protein structure stabilization, and a free cysteine residue, substituted by serine only in the pheromonal protein Darcin (MUP20). The free cysteine is recognized as responsible for the onset of inter- or intramolecular thiol/disulphide exchange, an event that favours protein aggregation. Here we show that the substitution of selected cysteine residues modulates Mus m 1.0102 protein folding, fold stability and unfolding reversibility, while maintaining its allergenic potency. Recombinant allergens used for immunotherapy or employed in allergy diagnostic kits require, as essential features, conformational stability, sample homogeneity and proper immunogenicity. In this perspective, recombinant Mus m 1.0102 might appear reasonably adequate as lead molecule because of its allergenic potential and thermal stability. However, its modest resistance to aggregation renders the protein unsuitable for pharmacological preparations. Point mutation is considered a winning strategy. We report that, among the tested mutants, C138A mutant acquires a structure more resistant to thermal stress and less prone to aggregation, two events that act positively on the protein shelf life. Those features make that MUP variant an attractive lead molecule for the development of a diagnostic kit and/or a vaccine

Molecules Present in Plant Essential Oils for Prevention and Treatment of Colorectal Cancer (CRC)

Essential oils (EOs) are a complex mixture of hydrophobic and volatile compounds synthesized from aromatic plants, commonly present in the human diet. In recent years, many in vitro studies have suggested possible anticancer properties of single EO compounds, on colorectal cancer (CRC) cells. However, the majority of these studies did not compare the effects of these compounds on normal and cancer colon cells. By using NCM-460, a normal human mucosal epithelial cell line, Caco-2, a human colon epithelial adenocarcinoma cell line, and SW-620, colon cancer cells derived from lymph node metastatic site, we identified cinnamaldehyde, derived from cinnamon EO and eugenol, derived from bud clove EO, as compounds with a specific anticancer action selectively targeting the transformed colonic cells. Both cinnamaldehyde (75 M) and eugenol (800 M), after 72 h of treatment, were capable to induce apoptosis, necrosis and a cell cycle slowdown in Caco-2 and in SW-620, but not in NCM-460 cells. If associated with a targeted delivery to the colon, these two compounds could prove effective in the prevention or treatment of CRC

Structure and Backbone Dynamics of Apo- and Holo-cellular Retinol-binding Protein in Solution

Retinoid-binding proteins play an important role in regulating transport, storage, and metabolism of vitamin A and its derivatives. The solution structure and backbone dynamics of rat cellular retinol-binding protein type I (CRBP) in the apo- and holo-form have been determined and compared using multidimensional high resolution NMR spectroscopy. The global fold of the protein is consistent with the common motif described for members of the intracellular lipid-binding protein family. The most relevant difference between the NMR structure ensembles of apo- and holoCRBP is the higher backbone disorder, in the ligand-free form, of some segments that frame the putative entrance to the ligand-binding site. These comprise alpha-helix II, the subsequent linker to beta-strand B, the hairpin turn between beta-strands C and D, and the betaE-betaF turn. The internal backbone dynamics, obtained from 15N relaxation data (T1, T2, and heteronuclear nuclear Overhauser effect) at two different fields, indicate several regions with significantly higher backbone mobility in the apoprotein, including the betaC-betaD and betaE-betaF turns. Although apoCRBP contains a binding cavity more shielded than that of any other retinoid carrier, conformational flexibility in the portal region may assist retinol uptake. The stiffening of the backbone in the holoprotein guarantees the stability of the complex during retinol transport and suggests that targeted retinol release requires a transiently open state that is likely to be promoted by the acceptor or the local environment

Responses of peripheral blood mononucleated cells from non-celiac gluten sensitive patients to various cereal sources

Non-celiac gluten sensitivity (NCGS) is still an undefined syndrome whose triggering mechanisms remain unsettled. This study aimed to clarify how cultured peripheral blood mononucleated cells (PBMC) obtained from NCGS patients responded to contact with wheat proteins. Results demonstrated that wheat protein induced an overactivation of the proinflammatory chemokine CXCL10 in PBMC from NCGS patients, and that the overactivation level depends on the cereal source from which proteins are obtained. CXCL10 is able to decrease the transepithelial resistance of monolayers of normal colonocytes (NCM 460) by diminishing the mRNA expression of cadherin-1 (CDH1) and tight junction protein 2 (TJP2), two primary components of the tight junction strands. Thus, CXCL10 overactivation is one of the mechanisms triggered by wheat proteins in PBMC obtained from NCGS patients. This mechanism is activated to a greater extent by proteins from modern with respect to those extracted from ancient wheat genotypes

Gene Structure and M20T Polymorphism of theSchistosoma mansoni Sm14 Fatty Acid-binding Protein

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Ancient pathogen-driven adaptation triggers increased susceptibility to non-celiac wheat sensitivity in present-day European populations

Details of sequence profiles for each NCWS subject. (XLSX 47 kb

The NMR-derived solution structure of a new cationic antimicrobial peptide from the skin secretion of the anuran Hyla punctata.

Amphibian skin secretions constitute an important source of molecules for antimicrobial drug research in order to combat the increasing resistance of pathogens to conventional antibiotics. Among the various types of substances secreted by the dermal granular amphibian glands, there is a wide range of peptides and proteins, often displaying potent antimicrobial activities and providing an effective defense system against parasite infection. In the present work, we report the NMR solution structure and the biological activity of a cationic 14-residue amphiphilic alpha-helical polypeptide named Hylaseptin P1 (HSP1), isolated from the skin secretion of the hylid frog Hyla punctata. The peptide antimicrobial activity was verified against Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, whereas no significant lytic effect was detected toward red or white blood cells

Peptides of the Constant Region of Antibodies Display Fungicidal Activity

Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA) of antibodies (Fc-peptides) exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models. It is intriguing to hypothesize that some Fc-peptides may influence the antifungal immune response and constitute the basis for devising new antifungal agents