References of "Versali, Marie-France"
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See detailPurification and characterisation of a 31 kDa chitinase from the Myzus persicae aphid, a target for Hemiptera biocontrol
Francis, Frédéric ULg; Saguez, Julien; Cherqui, Anas et al

in Applied Biochemistry and Biotechnology (2012), 166

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See detailMethod for the production of recombinant proteins by green microalgae
Versali, Marie-France ULg; Clerisse, Fabienne ULg; Dommes, Jacques ULg et al

Patent (2011)

The present invention relates to a method for the production of recombinant proteins by algal cells, which are fresh water unicellular green microalgae belonging to the order of Sphaeropleales. The ... [more ▼]

The present invention relates to a method for the production of recombinant proteins by algal cells, which are fresh water unicellular green microalgae belonging to the order of Sphaeropleales. The present invention further provides recombinant algal cells, wherein said algal cells are fresh water unicellular green microalgae belonging to the order of Sphaeropleales, and wherein said algal cells are capable of producing a recombinant protein. The invention is also directed to a method for selecting recombinant algal cells. The invention also relates to the use of recombinant algal cells as described herein for producing recombinant proteins. [less ▲]

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See detailCharacterization and Cloning of Chitin Deacetylases from Rhizopus Circinans
Gauthier, Carole ULg; Clerisse, Fabienne ULg; Dommes, Jacques ULg et al

in Protein Expression & Purification (2008), 59

Chitin deacetylase catalyzes hydrolysis of the acetamido groups of N-acetylglucosamine of chitin in fungal cell walls. Here a chitin deacetylase secreted by Rhizopus circinans was purified to homogeneity ... [more ▼]

Chitin deacetylase catalyzes hydrolysis of the acetamido groups of N-acetylglucosamine of chitin in fungal cell walls. Here a chitin deacetylase secreted by Rhizopus circinans was purified to homogeneity and partially characterized. The enzyme exhibits an apparent molecular weight of approximately 75kDa. At 37 degrees C it shows optimal activity at pH 5.5-6. Its pH stability and thermal stability are good. Mn(2+) and Mg(2+) slightly enhance the activity of the enzyme and Cu(2+) strongly inhibits it. An R. circinans cDNA library was constructed and screened with a homologous probe synthesized by RT-PCR or with synthetic primers derived from the N-terminal amino-acid sequence of the native purified chitin deacetylase. Three chitin deacetylase cDNAs (RC, D2, and I3/2) were isolated from the cDNA library and sequenced. These cDNAs exhibit features characteristic of chitin deacetylase sequences: the presence of a polysaccharide deacetylase domain, a metal-binding triad, the conserved catalytic residues, and high homology with various chitin deacetylase genes. The cDNAs were cloned in a Pichia pastoris expression system and produced as polyhistidine-tagged proteins. Only one recombinant enzyme (called RC) was active under the tested conditions. It was purified to homogeneity in a single step and further characterized. The protein showed an apparent molecular mass of approximately 75kDa and, like the native enzyme, showed optimal activity at pH 5.5-6 at 37 degrees C. It was strongly inhibited by Cu(2+). The isolation of several chitin deacetylase cDNAs from the same microorganism is discussed. [less ▲]

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See detailGlycol chitosan improves the efficacy of intranasally administrated replication defective human adenovirus type 5 expressing glycoprotein D of bovine herpesvirus 1
Gogev, S.; de Fays, K.; Versali, Marie-France ULg et al

in Vaccine (2004), 22(15-16), 1946-1953

The ability of two soluble formulations, namely chitosan and glycol chitosan, when used as an intranasal adjuvant, to improve the immunogenicity of an intranasal human adenovirus type 5 replication ... [more ▼]

The ability of two soluble formulations, namely chitosan and glycol chitosan, when used as an intranasal adjuvant, to improve the immunogenicity of an intranasal human adenovirus type 5 replication defective expressing bovine herpesvirus 1 (BoHV-1) glycoprotein D based vaccine, was investigated in cattle. Their adjuvant effects on immune response by increasing clinical and especially virological protection against an intranasal BoHV-1 challenge were then evaluated. The best virological protection was obtained in calves immunized with the vaccine vector adjuvanted with glycol chitosan which decreased the challenge BoHV-1 virus excretion titres by 0.5-1.5 log when compared to those obtained in calves immunized with the vaccine vector alone or adjuvanted with chitosan. A slight difference in clinical scores was observed in calves immunized with the adjuvanted vaccine vector compared to calves immunized with the vaccine vector alone. The obtained data suggest that the tested soluble formulation of glycol chitosan has promising potential use as an intranasal adjuvant for recombinant viral vector vaccines in cattle. (C) 2003 Elsevier Ltd. All rights reserved. [less ▲]

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See detailLes chitosanes – nouveaux adjuvants pour la vaccination par voie muqueuse chez les animaux
Gogev, S.; Versali, Marie-France ULg; Thiry, Etienne ULg

in Annales de Médecine Vétérinaire (2003), 147(5, OCT-NOV), 343-350

The advantage of mucosal vaccination is the induction of an immune response at entry sites of pathogens. Because vaccines alone are poorly bioavailable after mucosal administration, they need to be co ... [more ▼]

The advantage of mucosal vaccination is the induction of an immune response at entry sites of pathogens. Because vaccines alone are poorly bioavailable after mucosal administration, they need to be co-administered with penetration enhancers, or adjuvants. Numerous studies have demonstrated that chitosans and their derivatives are safe and effective mucosal absorption enhancers of hydrophylic macromolecules such as peptides and proteins. Chitosan is a cationic polysaccharide derived from chitin present in the covering layer of arthropods and in the cell walls of many fungi. Association of vaccines to chitosans, their derivatives or some of their particulate systems, such as nano- and microparticles, has also shown to enhance antigen uptake by mucosal lymphoid tissues, thereby inducing mucosal and systemic immune responses against these antigens. Chitosan and its derivatives are promising adjuvants for mucosal vaccine delivery in animals. [less ▲]

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See detailPotential of using Daphnia magna (crustacea) developing in an aerated waste stabilisation pond as a commercial source of chitin
Cauchie, Henry-Michel ULg; Versali, Marie-France ULg; Hoffmann, L. et al

in Aquaculture (2002), 205(1-2), 103-117

The potential of using the planktonic crustacean Daphnia magna as a commercial source of chitin was studied on the basis of the estimation of the amount of chitin produced annually by this species and the ... [more ▼]

The potential of using the planktonic crustacean Daphnia magna as a commercial source of chitin was studied on the basis of the estimation of the amount of chitin produced annually by this species and the specifications of this kind of chitin. D. magna was found to have a significant chitin content, ranging from 3% to 7% of the body dry weight. During three consecutive years, chitin biomass (B) and daily somatic chitin production (daily P-SOM) were monitored in a 59,000-m(2) aerated waste stabilisation pond located in the Grand-Duchy of Luxembourg (Western Europe). These variables were found to vary a lot seasonally. Maximum values were observed in summer (B > 40 kg chitin; daily P-SOM > 20 kg chitin day(-1)). Annual somatic chitin production reached on average 1200 kg chitin year(-1). The amount of chitin generated by the moulting of the daphnids (i.e. chitin contained in the exuviae) can also constitute a significant source of chitin, reaching about 1220 kg chitin year(-1). Chitin was isolated from D. magna, following three different processing routes. The specifications of the isolated and purified chitin were similar to those of commercial chitin extracted from crabs and shrimps. The average molecular weight varied from 600,000 to 2,600,000 depending on the processing route, The isolated chitin had a low N content indicating a high degree of acetylation. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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