Search results for "Lucan"

Identification of glucan-mannoprotein complexes in the cell wall of Candida albicans using a monoclonal antibody that reacts with a (1,6)- -glucan ep…

1995

The use of a novel monoclonal antibody (mAb) that reacts with (1,6)-beta-glucan has permitted the study of the different covalent linkages between glucan and mannoproteins in the cell wall of Candida albicans. The mAb JRR1 was originally raised by immunization with Zymolyase extracts from C. albicans cell walls, but it soon became apparent that it reacted with a (1,6)-beta-glucan epitope. By using this antibody, we show the existence of glucan-mannoprotein complexes between the (1,6)-beta-glucan epitope recognized by the antibody and cell wall mannoproteins. The topology of the (1,6)-beta-glucan in the cell wall of C. albicans has also been studied.

Trattamento immunomodulante delle lesioni pre-cancerose della cervice uterina ( LSIL ) con beta-glucani

2014

Il tumore della cervice uterina rappresenta oggi l'esempio più eclatante di neoplasia associata a fattori immunologici. Uno dei fattori di rischio principali di tale malattia è, infatti, l'infezione da HPV ( Human papillomavirus). L'incidenza di tale infezione risulta essere direttamente proporzionale all'entità della lesione neoplastica arrivando a toccare quota 89% nel cancro invasivo della cervice. Lo scopo del nostro lavoro è stato quello di osservare come un aumento della risposta immunitaria cellulo-mediata indotta dai Beta-glucani possa influenzare la risoluzione delle lesioni precancerose di basso grado della cervice uterina ( LSIL ). Sono state prese in considerazione, dal 2009 al …

Xyloglucan self-assembled nanostructures and gels for biomedical applications

Patterns of wall synthesis inSaccharomyces cerevisiae

1979

Wall formation inSaccharomyces cerevisiae seems to be the result of two main patterns of wall material deposition: (i) around the whole periphery of the cell in nonbudding ones, and (ii) mainly at the tip of the daughter cell or at the cross wall that separates dividing cells. This interpretation has been obtained following experiments in which RNA or protein synthesis has been inhibited. Under these conditions, glucan formation takes place, and wall thickening is probably due to the accumulation of this polysaccharide. Furthermore, once a pattern of wall deposition has been established, it is not modified by inhibition of RNA or protein synthesis.

Chemical gels of scleroglucan obtained by cross-linking with 1,w-dicarboxylic acids: Synthesis and characterization

2005

Chemical gels obtained by cross-linking reaction between scleroglucan and I, omega-dicarboxylic acids having a number of carbon atoms from 4 to 8 in the chain, have been prepared and characterised. The networks show properties correlated with the number of carbon atoms of the acid and with the molar ratio carboxylic acid/glucose unit of the polymer (r) employed in the cross-linking reaction. The diffusion of theophylline, chosen as model drug, through the swelled cross-linked polymers has been also investigated and it has enabled the diffusion coefficients of the drug to be calculated under different environmental conditions. The release profiles of theophylline from tablets prepared with t…

Xyloglucan-derived oligosaccharides induce ethylene synthesis in persimmon (Diospyros kaki L.) fruit

1998

In this work the effect of injection of xyloglucan-derived oligosaccharides (XGOs) into whole persimmon (Diospyros kaki L.) fruits on ethylene biosynthesis was investigated. Fruits collected during different ripening stages produced low levels of ethylene without a climacteric-like peak. Pretreatment of these fruits with 10 cm 3 C 2 H4 m -3 for 8 h stimulated little or no endogenous ethylene production. However, when persimmon fruits were injected with a mixture of XGOs a burst in ethylene production was observed compared with water-injected control fruits or fruits injected with different monosaccharide solutions. In order to study the influence of oligosaccharide structure and fruit ripen…

Synthesis and Assembly of Wall Polymers on Regenerating Yeast Protoplasts

1983

Accumulation of chitin and glucan on S. cerevisiae and C. albicans protoplasts begins shortly after resuspension in the regeneration medium, and mannoprotein molecules also appear retained by the regenerating wall after 30–60 minutes in S. cerevisiae or after a longer lag period in C. albicans. Nevertheless, a considerable fraction of the synthesized mannoproteins, which in SDS-acrylamide gels exhibit a different pattern from that of wall mannoproteins of cells, are still released to the growth medium during at least eight hours. De novo synthesis of chitin synthase, but not of glucan synthase, is observed in S. cerevisiae from about 30 minutes after initiation of the regeneration process. …

Polydimethylsiloxanes with amylose side chains by enzymatic polymerization

1996

Maltoheptaonamide modified polydimethylsiloxane was prepared applying a simplified synthetic pathway in the derivatization sequence of the carbohydrate. The products were characterized by 13C NMR and FT-IR spectroscopy. The glucan side chains of these “sweet siloxanes” were elongated by enzymatic catalysis with potato phosphorylase.

Interpolymer complexes and polymer compatibility.

2012

A reliable method to decide whether two polymers A and B are miscible or incompatible would be very helpful in many ways. In this contribution we demonstrate why traditional procedures cannot work. We propose to use the intrinsic viscosities [η] of the polymer blends instead of the composition dependence of the viscosities as a criterion for polymer miscibility. Two macromolecules A and B are miscible because of sufficiently favorable interactions between the two types of polymer segments. For solutions of these polymers in a joint solvent, this Gibbs energetic preference of dissimilar intersegmental contacts should prevail upon dilution and lead to the formation of interpolymer complexes, …

Saccharide modified silica particles by enzymatic grafting

1997

The surface of silica particles has been chemically modified with oligo- or poly-(α,1→4)-D-glucopyranose (amylose) chains of various length by covalently attaching maltoheptaose derivatives to the solid support and enzymatic polymerization of glucose-1-phosphate with a potato phosphorylase as catalyst. The characterization of the products by solid-state NMR spectroscopy showed an interesting dependence of the linewidth with the grafting density of the glucan chains. The modified silica particles showed chiral discrimination in liquid chromatography.