3 research outputs found
Development of Clickable Monophosphoryl Lipid A Derivatives toward Semisynthetic Conjugates with Tumor-Associated Carbohydrate Antigens
A semisynthetic strategy to obtain
monophosphoryl lipid A derivatives
equipped with clickable (azide, alkyne, double bond, or thiol precursor)
moieties, starting from the native lipid A isolated from <i>Escherichia
coli</i>, is presented. These lipid A derivatives can be conjugated
with other interesting biomolecules, such as tumor-associated carbohydrate
antigens (TACAs). In this way, the immunostimulant activity of monophosphoryl
lipid A can significantly improve the immunogenicity of TACAs, thus
opening access to potential self-adjuvant anticancer vaccine candidates.
A monophosphoryl lipid A–Thomson-Friedenreich (TF) antigen
conjugate was obtained to demonstrate the feasibility of this methodology,
which stands as a valuable, rapid, and scalable alternative to the
highly complex approaches of total synthesis recently reported to
the same aim. A preliminary evaluation of the immunological activity
of this conjugate as well as of other semisynthetic lipid A derivatives
was also reported
Inside out <i>Porphyridium cruentum</i>: Beyond the Conventional Biorefinery Concept
Here, an unprecedented
biorefinery approach has been designed to
recover high-added value bioproducts starting from the culture ofPorphyridium cruentum. This unicellular marine red
alga can secrete and accumulate high-value compounds that can find
applications in a wide variety of industrial fields. 300 ± 67
mg/L of exopolysaccharides were obtained from cell culture medium;
phycoerythrin was efficiently extracted (40% of total extract) and
isolated by single chromatography, with a purity grade that allowed
the crystal structure determination at 1.60 Å; a twofold increase
in β-carotene yield was obtained from the residual biomass;
the final residual biomass was found to be enriched in saturated fatty
acids. Thus, for the first time, a complete exploitation ofP. cruentumculture was set up
A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium <i>Colwellia psychrerythraea</i> 34H That Mimics Antifreeze (Glyco)proteins
The
low temperatures of polar regions and high-altitude environments,
especially icy habitats, present challenges for many microorganisms.
Their ability to live under subfreezing conditions implies the production
of compounds conferring cryotolerance. <i>Colwellia psychrerythraea</i> 34H, a γ-proteobacterium isolated from subzero Arctic marine
sediments, provides a model for the study of life in cold environments.
We report here the identification and detailed molecular primary and
secondary structures of capsular polysaccharide from <i>C. psychrerythraea</i> 34H cells. The polymer was isolated in the water layer when cells
were extracted by phenol/water and characterized by one- and two-dimensional
NMR spectroscopy together with chemical analysis. Molecular mechanics
and dynamics calculations were also performed. The polysaccharide
consists of a tetrasaccharidic repeating unit containing two amino
sugars and two uronic acids bearing threonine as substituent. The
structural features of this unique polysaccharide resemble those present
in antifreeze proteins and glycoproteins. These results suggest a
possible correlation between the capsule structure and the ability
of <i>C. psychrerythraea</i> to colonize subfreezing marine
environments