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β- D-Glc pA-(1→2)-[ β- D-Xyl p-(1→2)- α- D-Man p-(1→3)]- α- D-Man p-(1→3)- α- D-Man p, the repeating unit of the exopolysaccharide from Cryptococcus neoformans serotype D, was synthesized as its 4-methoxyphenyl glycoside. The approach presented here also provides a route to the synthesis of more complex repeating units of glucuconoxylomannan (GXM) of C. neoformans serotypes A-C. [ABSTRACT FROM AUTHOR]

A previously discovered posttranslational modification strategy - arginine rhamnosylation - is essential for elongation factor P (EF-P) dependent rescue of polyproline stalled ribosomes in clinically relevant species such as Pseudomonas aeruginosa and Neisseria meningitidis . However, almost nothing is known about this new type of N -linked glycosylation. In the present study we used NMR spectroscopy to show for the first time that the α anomer of rhamnose is attached to Arg32 of EF-P, demonstrating that the corresponding glycosyltransferase EarP inverts the sugar of its cognate substrate dTDP-β-l-rhamnose. Based on this finding we describe the synthesis of an α-rhamnosylated arginine containing peptide antigen in order to raise the first anti -rhamnosyl arginine specific antibody ( anti -Arg Rha ). Using ELISA and Western Blot analyses we demonstrated both its high affinity and specificity without any cross-reactivity to other N -glycosylated proteins. Having the anti -Arg Rha at hand we were able to visualize endogenously produced rhamnosylated EF-P. Thus, we expect the antibody to be not only important to monitor EF-P rhamnosylation in diverse bacteria but also to identify further rhamnosyl arginine containing proteins. As EF-P rhamnosylation is essential for pathogenicity, our antibody might also be a powerful tool in drug discovery.

Background: Immunotherapy is emerging as a promising cure for cancer. However, a severe problem in this area is the immune tolerance to tumor cells and tumor-associated antigens, as evidenced by the ability of cancer to escape immune surveillance. To overcome this problem this work examined the potential of improving the antigenicity of myeloma by metabolic engineering of its cell surface carbohydrate antigens (i.e., glycoengineering) and presentation of the modified tumor antigens by dendritic cells (DCs) to generate cytotoxic T-lymphocytes (CTLs)., Methods: CD138+ myeloma cells were isolated from 11 multipe myeloma (MM) patients by the immunomagnetic bead method. The MM cells were treated with N-propionyl-D-mannosamine (ManNPr), a synthetic analog of N-acetyl-D-mannosamine (ManNAc), the natural biosynthetic precursor of N-acetyl sialic acid (NeuNAc), to express unnatural N-propionylated sialoglycans. The glycoengineered cells were then induced to apoptosis, and the apoptotic products were added to cultured functional DCs that could present the unnatural carbohydrate antigens to autologous T-lymphocytes., Results: It was found that the resultant DCs could activate CD4+ and CD8+ T-lymphocytes, resulting in increased expression of T cell surface markers, including CD8CD28 and CD4CD29. Moreover, upon stimulation by glycoengineered MM cells, these DC-activated T-lymphocytes could release significantly higher levels of IFN-gamma (P < 0.05). Lactate dehydrogenase (LDH) assays further showed that the stimulated T-lymphocytes were cytotoxic to glycoengineered MM cells., Conclusions: This work demonstrated that glycoengineered myeloma cells were highly antigenic and the CTLs induced by the DCs loaded with the unnatural myeloma antigens were specifically cytotoxic to the glycoengineered myeloma. This may provide a new strategy for overcoming the problem of immune tolerance for the development of effective immunotherapies for MM.

A series of fluconazole (1) analogues, compounds 3a-k, were prepared as potential antifungal agents. They were designed by computational docking experiments to the active site of the cytochrome P450 14alpha-sterol demethylase (CYP51), whose crystal structure is known. Preliminary biological tests showed that most of the target compounds exhibit significant activities against the eight most-common pathogenic fungi. Thereby, the most potent congener, 1-[(4-tert-butylbenzyl)(cyclopropyl)amino]-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ol (3j), was found to exhibit a broad antifungal spectrum, being more active against Candida albicans, Candida tropicalis, Cryptococcus neoformans, Microsporum canis, and Trichophyton rubrum (MIC80 < 0.125 microg/ml) than the standard clinical drug itraconazole (2). The observed affinities of the lead molecules towards CYP51 indicate that a cyclopropyl residue enhances binding to the target enzyme. Our results may provide some guidance for the development of novel triazole-based antifungal lead structures.

Objective: To identify and analyse the different species, same species in different regions and confusion species., Method: Near-infrared diffuse reflectance spectrometry was used., Result: Clustering analysis showed that clustering relations were far among different Gryllotalpa species and close among the same species from different regions, and there were close relations among the same species from near regions and between Teleogryllus emmus and G. orientalis., Conclusion: Near-infrared diffuse reflectance spectrometry method can be used in classification and identification of Gryllotalpa.