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ABSTRACT
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The invalidly published name Aspergillus sydowii var. mulundensis was proposed for a strain of Aspergillus that produced new echinocandin metabolites designated as the mulundocadins. Reinvestigation of this strain (Y-30462=DSMZ 5745)... more
The invalidly published name Aspergillus sydowii var. mulundensis was proposed for a strain of Aspergillus that produced new echinocandin metabolites designated as the mulundocadins. Reinvestigation of this strain (Y-30462=DSMZ 5745) using phylogenetic, morphological, and metabolic data indicated that it is a distinct and novel species of Aspergillus sect. Nidulantes. The taxonomic novelty, Aspergillus mulundensis, is introduced for this historically important echinocandin-producing strain. The closely related A. nidulans FGSC A4 has one of the most extensively characterized secondary metabolomes of any filamentous fungus. Comparison of the full-genome sequences of DSMZ 5745 and FGSC A4 indicated that the two strains share 33 secondary metabolite biosynthetic gene clusters. These shared gene clusters represent ~45% of the total secondary metabolome of each strain, thus indicating a high level intraspecific divergence in terms of secondary metabolism.The Journal of Antibiotics advanc...
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1. Genet Eng (NY). 1993;15:191-212. Molecular biology and genetics of protective fungal endophytes of grasses. Schardl CL, An Z. Department of Plant Pathology, University of Kentucky, Lexington 40546-0091. PMID: 7763840 [PubMed - indexed... more
1. Genet Eng (NY). 1993;15:191-212. Molecular biology and genetics of protective fungal endophytes of grasses. Schardl CL, An Z. Department of Plant Pathology, University of Kentucky, Lexington 40546-0091. PMID: 7763840 [PubMed - indexed for MEDLINE]. ...
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... Japan Isao Fujii Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan Robert Giacobbe Merck Research ... Sciences, Massey University, Palmerston North, New Zealand Gary A. Payne Department of Plant... more
... Japan Isao Fujii Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan Robert Giacobbe Merck Research ... Sciences, Massey University, Palmerston North, New Zealand Gary A. Payne Department of Plant Pathology, North Carolina, State University ...
Operons are multigene transcriptional units which occur mostly in prokaryotes but rarely in eukaryotes. Protein-coding operons have not been reported in the Fungi even though they represent a very diverse kingdom of organisms. Here, we... more
Operons are multigene transcriptional units which occur mostly in prokaryotes but rarely in eukaryotes. Protein-coding operons have not been reported in the Fungi even though they represent a very diverse kingdom of organisms. Here, we report a functional operon involved in the secondary metabolism of the fungus Glarea lozoyensis belonging to Leotiomycetes (Ascomycota). Two contiguous genes, glpks3 and glnrps7, encoding polyketide synthase and nonribosomal peptide synthetase, respectively, are cotranscribed into one dicistronic mRNA under the control of the same promoter, and the mRNA is then translated into two individual proteins, GLPKS3 and GLNRPS7. Heterologous expression in Aspergillus nidulans shows that the GLPKS3-GLNRPS7 enzyme complex catalyzes the biosynthesis of a novel pyrrolidinedione-containing compound, xenolozoyenone (compound 1), which indicates the operon is functional. Although it is structurally similar to prokaryotic operons, the glpks3-glnrps7 operon locus has ...
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The echinocandins are a class of antifungal drugs that includes caspofungin, micafungin, and anidulafungin. Gene clusters encoding most of echinocandin structural complexity provided a framework for hypotheses about the evolutionary... more
The echinocandins are a class of antifungal drugs that includes caspofungin, micafungin, and anidulafungin. Gene clusters encoding most of echinocandin structural complexity provided a framework for hypotheses about the evolutionary history and chemical logic of echinocandin biosynthesis. Gene orthologs among echinocandin-producing fungi were identified. Pathway genes including the nonribosomal peptide synthetases (NRPSs) were analyzed phylogenetically to address the hypothesis that these pathways were descended from a common ancestor. The clusters share a cooperative gene content and linkages among the different strains. Individual pathway genes formed unique echinocandin-exclusive phylogenetic lineages when analyzed in the context of similar genes. The echinocandin NRPSs, along with the NRPS from the inp gene cluster in Aspergillus nidulans and its orthologs, comprise a novel lineage among fungal NRPSs. NRPS adenylation domains from different species exhibited one-to-one correspon...
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Pneumocandins are lipohexapeptides of the echinocandin family that potently interrupt fungal cell wall biogenesis by non-competitive inhibition of 1,3-β-glucan synthase. The pneumocandin biosynthetic gene cluster was previously elucidated... more
Pneumocandins are lipohexapeptides of the echinocandin family that potently interrupt fungal cell wall biogenesis by non-competitive inhibition of 1,3-β-glucan synthase. The pneumocandin biosynthetic gene cluster was previously elucidated by whole genome sequencing. In addition to the core non-ribosomal peptide synthetase and polyketide synthase (GLNRPS4 and GLPKS4), the pneumocandin biosynthetic cluster includes two P450-type hemeprotein monooxygenase genes (GLP450-1 and GLP450-2) and four nonheme mononuclear iron oxygenase genes (GLOXY1, GLOXY2, GLOXY3, and GLOXY4), which function to biosynthesize and create the unusual sequence of hydroxylated amino acids of the mature pneumocandin peptide. Insertional inactivation of three of these genes (GLP450-1, GLP450-2 and GLOXY1) generated 13 different pneumocandins analogues that lack one, two, three or four hydroxyl groups on 4R,5R-dihydroxy-ornithine and 3S,4S-dihydroxy-homotyrosine of the parent hexapeptide. Among them, seven analogues...
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Non-ribosomal peptide synthetases (NRPSs) are a primary modality for fungal peptidic natural product assembly and are responsible for some of the best known, most useful, and most destructive fungal metabolites. Through genome sequencing... more
Non-ribosomal peptide synthetases (NRPSs) are a primary modality for fungal peptidic natural product assembly and are responsible for some of the best known, most useful, and most destructive fungal metabolites. Through genome sequencing and computer-assisted recognition of modular motifs of catalytic domains, one can now confidently identify most NRPS biosynthetic genes of a fungal strain. The biosynthetic gene clusters responsible for two of the most important classes of NRP fungal derived drugs, cyclosporine and the echinocandins, have been recently characterized by genomic sequencing and annotation. Complete biosynthetic gene clusters for the pneumocandins and echinocandins have been mapped at the genetic level and functionally characterized to some extent. Genomic sequencing of representative strains of most of the variants in the echinocandin family, including the wild-type of the three fungal strains employed for industrial-scale production of caspofungin, micafungin and anid...
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We have previously described a novel artificial NFEV β-secretase (BACE1) cleavage site, which when introduced into the amyloid-β precursor protein (APP), significantly enhances APP cleavage by BACE1 in in vitro and cellular assays. In... more
We have previously described a novel artificial NFEV β-secretase (BACE1) cleavage site, which when introduced into the amyloid-β precursor protein (APP), significantly enhances APP cleavage by BACE1 in in vitro and cellular assays. In this study, we describe the identification and characterization of a single chain fragment of variable region (scFv), specific to the EV neo-epitope derived from BACE1 cleavage of the NFEV-containing peptide, and its conversion to IgG1. Both the scFv displayed on phage and EV-IgG1 show exquisite specificity for binding to the EV neoepitope without cross-reactivity to other NFEV containing peptides or WT-APP KMDA cleavage products. EV-IgG1 can detect as little as 0.3 nmol/L of the EV peptide. EV-IgG1 antibody was purified, conjugated with alkaline phosphatase and utilized in various biological assays. In the BACE1 enzymatic assay using NFEV substrate, a BACE1 inhibitor MRK-3 inhibited cleavage with an IC(50) of 2.4 nmol/L with excellent reproducibility....
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1. Genet Eng (NY). 1993;15:191-212. Molecular biology and genetics of protective fungal endophytes of grasses. Schardl CL, An Z. Department of Plant Pathology, University of Kentucky, Lexington 40546-0091. PMID: 7763840 [PubMed - indexed... more
1. Genet Eng (NY). 1993;15:191-212. Molecular biology and genetics of protective fungal endophytes of grasses. Schardl CL, An Z. Department of Plant Pathology, University of Kentucky, Lexington 40546-0091. PMID: 7763840 [PubMed - indexed for MEDLINE]. ...
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The presence of neutralizing epitopes in human papillomavirus (HPV) L1 virus-like particles (VLPs) is the structural basis of prophylactic vaccines. An anti-HPV16 neutralizing monoclonal antibody (N-mAb) 26D1 was isolated from a memory B... more
The presence of neutralizing epitopes in human papillomavirus (HPV) L1 virus-like particles (VLPs) is the structural basis of prophylactic vaccines. An anti-HPV16 neutralizing monoclonal antibody (N-mAb) 26D1 was isolated from a memory B cell of a human vaccinee. The pre-binding of heparan sulfate to VLPs inhibited the binding of both N-mAbs to the antigen, indicating that the epitopes are critical for viral cell attachment/entry. Hybrid VLP binding with surface loop swapping between types indicated the essential roles of the DE and FG loops for both 26D1 (DEa in particular) and H16.V5 binding. Specifically, Tyr(135) and Val(141) on the DEa loop were shown to be critical residues for 26D1 binding via site-directed mutagenesis. Partially overlap between the epitopes between 26D1 and H16.V5 was shown using pairwise epitope mapping, and their binding difference is demonstrated to be predominantly in DE loop region. In addition, 26D1 epitope is immunodominant epitope recognized by both ...
Pneumocandins produced by the fungus Glarea lozoyensis are acylated cyclic hexapeptides of the echinocandin family. Pneumocandin B0 is the starting molecule for the first semisynthetic echinocandin antifungal drug, caspofungin acetate. In... more
Pneumocandins produced by the fungus Glarea lozoyensis are acylated cyclic hexapeptides of the echinocandin family. Pneumocandin B0 is the starting molecule for the first semisynthetic echinocandin antifungal drug, caspofungin acetate. In the wild-type strain, pneumocandin B0 is a minor fermentation product, and its industrial production was achieved by a combination of extensive mutation and medium optimization. The pneumocandin biosynthetic gene cluster was previously elucidated by a whole genome sequencing approach. Knowledge of the biosynthetic cluster suggested an alternative way to exclusively produce pneumocandin B0. Disruption of gl-oxy-4, a non-heme, α-ketoglutarate-dependent oxygenase, confirmed its involvement in l-leucine cyclization to form 4S-methyl-l-proline. Absence of 4S-methyl-l-proline abolishes pneumocandin A0 production, and 3S-hydroxyl-l-proline occupies the hexapeptide core's position 6 resulting in exclusive production of pneumocandin B0. Retrospective an...
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P24 antigen is the main structural protein of HIV-1, its detection provide a means to aid the early diagnosis of HIV-1 infection. The aim of this study was to improve the selectivity and sensitivity of the HIV P24 diagnostic assay by... more
P24 antigen is the main structural protein of HIV-1, its detection provide a means to aid the early diagnosis of HIV-1 infection. The aim of this study was to improve the selectivity and sensitivity of the HIV P24 diagnostic assay by developing a cohort of 9E8 affinity matured antibodies through in vitro phage affinity maturation which was performed by complementarity determining region (CDR)-hot spot mutagenesis strategy. Antibody 9E8-491 had an affinity constant of 5.64 × 10(-11) M, which was 5.7-fold higher than that of the parent antibody (9E8). Furthermore, the affinity, sensitivity, and specificity of 9E8-491 were higher than those of 9E8, which indicate that 9E8-491 is a good candidate detection antibody for HIV P24 assay. Structure analysis of matured variants revealed that most hydrogen bonds resided in HCDR3.Among the antibody-antigen predicted binding residues, Tyr(100A/100B) was the original conserved residue that was commonly present in HCDR3 of 9E8 and variants. Arg(10...