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Full-Text Articles in Organisms

N-Glycan Modification In Aspergillus Species, Elke Kainz, Andreas Gallmetzer, Christian Hatzl, Juergen H. Nett, Huijuan Li, Thorsten Schinko, Robert Pachlinger, Harald Berger, Yazmid Reyes-Dominguez, Andreas Bernreiter, Tillmann Gerngross, Stefan Wildt, Joseph Strauss Dec 2007

N-Glycan Modification In Aspergillus Species, Elke Kainz, Andreas Gallmetzer, Christian Hatzl, Juergen H. Nett, Huijuan Li, Thorsten Schinko, Robert Pachlinger, Harald Berger, Yazmid Reyes-Dominguez, Andreas Bernreiter, Tillmann Gerngross, Stefan Wildt, Joseph Strauss

Dartmouth Scholarship

The production by filamentous fungi of therapeutic glycoproteins intended for use in mammals is held back by the inherent difference in protein N-glycosylation and by the inability of the fungal cell to modify proteins with mammalian glycosylation structures. Here, we report protein N-glycan engineering in two Aspergillus species. We functionally expressed in the fungal hosts heterologous chimeric fusion proteins containing different localization peptides and catalytic domains. . This strategy allowed the isolation of a strain with a functional -1,2-mannosidase producing increased amounts of N-glycans of the Man 5 GlcNAc 2 type. This strain was further engineered by the introduction of …


Structure And Function Of A Chlorella Virus Encoded Glycosyltransferase, Ying Zhang, Ye Xiang, James L. Van Etten, Michael G. Rossmann Jan 2007

Structure And Function Of A Chlorella Virus Encoded Glycosyltransferase, Ying Zhang, Ye Xiang, James L. Van Etten, Michael G. Rossmann

James Van Etten Publications

Paramecium bursaria chlorella virus-1 encodes at least 5 putative glycosyltransferases that are probably involved in the synthesis of the glycan components of the viral major capsid protein. The 1.6 Å crystal structure of one of these glycosyltransferases (A64R) has a mixed α/β fold containing a central, six-stranded β-sheet flanked by α-helices. Crystal structures of A64R, complexed with UDP, CMP, or GDP, established that only UDP bound to A64R in the presence of Mn2+, consistent with its high structural similarity to glycosyltransferases which utilize UDP as the sugar carrier. The structure of the complex of A64R, UDP-glucose, and Mn2+ showed that …


Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten Jan 2007

Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten

James Van Etten Publications

Acanthocystis turfacea chlorella virus (ATCV-1), a prospective member of the family Phycodnaviridae, genus Chlorovirus, infects a unicellular, eukaryotic, chlorella-like green alga, Chlorella SAG 3.83, that is a symbiont in the heliozoon A. turfacea. The 288,047-bp ATCV-1 genome is the first virus to be sequenced that infects Chlorella SAG 3.83. ATCV-1 contains 329 putative protein-encoding and 11 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands and intergenic space is minimal. Thirty-four percent of the viral gene products resemble entries in the public databases, including some that are unexpected for a virus. For example, these …


Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski Jan 2007

Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski

James Van Etten Publications

Two genes encoding the putative polyamine biosynthetic enzymes agmatine iminohydrolase (AIH) and N-carbamoylputrescine amidohydrolase (CPA) were cloned from the chloroviruses PBCV-1, NY-2A and MT325. They were expressed in Escherichia coli to form C-terminal (His)6-tagged proteins and the recombinant proteins were purified by Ni2+- binding affinity chromatography. The biochemical properties of the two enzymes are similar to AIH and CPA enzymes from Arabidopsis thaliana and Pseudomonas aeruginosa. Together with the previously known virus genes encoding ornithine/arginine decarboxlyase (ODC/ADC) and homospermidine synthase, the chloroviruses have genes that encode a complete set of functional enzymes that synthesize the rare polyamine homospermidine from arginine …


Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang Jan 2007

Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang

Pharmacy Faculty Articles and Research

4-Thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 6603 1), and Aspergillus niger (ATCC 16404) (MIC = 4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks P-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by a-substitution. The unprecedented (+/-)-2-tiydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic …