Recombinant paracoccin reproduces the biological properties of the native protein and induces protective Th1 immunity against Paracoccidioides brasiliensis infection.

Background: Paracoccin is a dual-function protein of the yeast Paracoccidioides brasiliensis that has lectin properties and N-acetylglucosaminidase activities. Proteomic analysis of a paracoccin preparation from P. brasiliensis revealed that the sequence matched that of the hypothetical protein encoded by PADG-3347 of isolate Pb-18, with a polypeptide sequence similar to the family 18 endochitinases.

α-(1,4)-Amylase, but not α- and β-(1,3)-glucanases, may be responsible for the impaired growth and morphogenesis of Paracoccidioides brasiliensis induced by N-glycosylation inhibition.

The cell wall of Paracoccidioides brasiliensis, which consists of a network of polysaccharides and glycoproteins, is essential for fungal pathogenesis. We have previously reported that N-glycosylation of proteins such as N-acetyl-β-D-glucosaminidase is required for the growth and morphogenesis of P. brasiliensis.

Oral immunization with attenuated Salmonella vaccine expressing Escherichia coli O157:H7 intimin gamma triggers both systemic and mucosal humoral immunity in mice.

Human infections with EHEC such as O157:H7 have been a great concern for worldwide food-industry surveillance. This pathogen is commonly associated with bloody diarrhea that can evolve to the life-threatening hemolytic uremic syndrome. Animals are the natural reservoir where this pathogen remains asymptomatically, in steps of ingestion and colonization of the bowel.

Influence of N-glycosylation on the morphogenesis and growth of Paracoccidioides brasiliensis and on the biological activities of yeast proteins.

The fungus Paracoccidioides brasiliensis is a human pathogen that causes paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America. The cell wall of P. brasiliensis is a network of glycoproteins and polysaccharides, such as chitin, that perform several functions.

Tunicamycin inhibition of N-glycosylation of α-glucosidase from Aspergillus niveus: partial influence on biochemical properties.

Treatment of Aspergillus niveus with 30 μg tunicamycin/ml did not interfere with α-glucosidase production, secretion, or its catalytic properties. Fully- and under-glycosylated forms of the enzyme had similar molecular masses, ~56 kDa. Moreover, the absence of N-glycans did not affect either pH optimum (6.

Paracoccin from Paracoccidioides brasiliensis; purification through affinity with chitin and identification of N-acetyl-beta-D-glucosaminidase activity.

The dimorphic fungus Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, the most frequent systemic mycosis in Latin America. Our group has been working with paracoccin, a P. brasiliensis lectin with MM 70 kDa, which is purified by affinity with immobilized N-acetylglucosamine (GlcNAc).

Purification and biochemical characterization of a novel alpha-glucosidase from Aspergillus niveus.

An extracellular a-glucosidase produced by Aspergillus niveus was purified using DEAE-Fractogel ion-exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5% PAGE and 10% SDS-PAGE. The enzyme presented 29% of glycosylation, an isoelectric point of 6.

Mycoparasitism studies of Trichoderma harzianum strains against Rhizoctonia solani: evaluation of coiling and hydrolytic enzyme production.

The genus Trichoderma is a potential biocontrol agent against several phytopathogenic fungi. One parameter for its successful use is an efficient coiling process followed by a substantial production of hydrolytic enzymes. The interaction between fifteen isolates of Trichoderma harzianum and the soil-borne plant pathogen, Rhizoctonia solani, was studied by light microscopy and transmission electron microscopy (TEM).