Complexing amphotericin B with gold nanoparticles improves fungal clearance from the brains of mice infected with Cryptococcal neoformans.

Unlabelled: Amphotericin B (AmB) is used to treat cryptococcal meningoencephalitis. However, the mortality rate remains high. Higher doses of AmB in deoxycholate buffer (AmBd) are toxic to human red blood cells (hRBC) and have no effect on brain organism load in mice.

Iduronic acid in chondroitin/dermatan sulfate: biosynthesis and biological function.

The ability of chondroitin/dermatan sulfate (CS/DS) to convey biological information is enriched by the presence of iduronic acid. DS-epimerases 1 and 2 (DS-epi1 and 2), in conjunction with DS-4-O-sulfotransferase 1, are the enzymes responsible for iduronic acid biosynthesis and will be the major focus of this review. CS/DS proteoglycans (CS/DS-PGs) are ubiquitously found in connective tissues, basement membranes, and cell surfaces or are stored intracellularly.

A screening strategy for heterologous protein expression in Escherichia coli with the highest return of investment.

Heterologous protein expression in Escherichia coli is commonly used to obtain recombinant proteins for a variety of downstream applications. However, many proteins are not, or are only poorly, expressed in soluble form. High level expression often leads to the formation of inclusion bodies and an inactive product that needs to be refolded.

Dermatan 4-O-sulfotransferase 1 is pivotal in the formation of iduronic acid blocks in dermatan sulfate.

Chondroitin/dermatan sulfate is a highly complex linear polysaccharide ubiquitously found in the extracellular matrix and at the cell surface. Several of its functions, such as binding to growth factors, are mediated by domains composed of alternating iduronic acid and 4-O-sulfated N-acetylgalactosamine residues, named 4-O-sulfated iduronic acid blocks. These domains are generated by the action of two DS-epimerases, which convert D-glucuronic acid into its epimer L-iduronic acid, in close connection with 4-O-sulfation.

Two dermatan sulfate epimerases form iduronic acid domains in dermatan sulfate.

A second dermatan sulfate epimerase (DS-epi2) was identified as a homolog of the first epimerase (DS-epi1), which was previously described by our group. DS-epi2 is 1,222 amino acids long and has an approximately 700-amino acid N-terminal epimerase domain that is highly conserved between the two enzymes. In addition, the C-terminal portion is predicted to be an O-sulfotransferase domain.

Identification of the active site of DS-epimerase 1 and requirement of N-glycosylation for enzyme function.

Dermatan sulfate is a highly sulfated polysaccharide and has a variety of biological functions in development and disease. Iduronic acid domains in dermatan sulfate, which are formed by the action of two DS-epimerases, have a key role in mediating these functions. We have identified the catalytic site and three putative catalytic residues in DS-epimerase 1, His-205, Tyr-261, and His-450, by tertiary structure modeling and amino acid conservation to heparinase II.