Novoa E.M.,Barcelona Institute for Research in Biomedicine |
Novoa E.M.,Massachusetts Institute of Technology |
Camacho N.,Barcelona Institute for Research in Biomedicine |
Tor A.,Barcelona Institute for Research in Biomedicine |
And 19 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014
Malaria remains a major global health problem. Emerging resistance to existing antimalarial drugs drives the search for new antimalarials, and protein translation is a promising pathway to target. Here we explore the potential of the aminoacyl-tRNA synthetase (ARS) family as a source of antimalarial drug targets. First, a battery of known and novel ARS inhibitors was tested against Plasmodium falciparum cultures, and their activities were compared. Borrelidin, a natural inhibitor of threonyl-tRNA synthetase (ThrRS), stands out for its potent antimalarial effect. However, it also inhibits human ThrRS and is highly toxic to human cells. To circumvent this problem, we tested a library of bioengineered and semisynthetic borrelidin analogs for their antimalarial activity and toxicity. We found that some analogs effectively lose their toxicity against human cells while retaining a potent antiparasitic activity both in vitro and in vivo and cleared malaria from Plasmodium yoelii-infected mice, resulting in 100%mice survival rates. Our work identifies borrelidin analogs as potent, selective, and unexplored scaffolds that efficiently clear malaria both in vitro and in vivo. © 2014, National Academy of Sciences. All rights reserved.
Goss R.J.M.,University of East Anglia |
Lanceron S.,University of East Anglia |
Roy A.D.,University of East Anglia |
Sprague S.,Biotica Technology Ltd. |
And 4 more authors.
ChemBioChem | Year: 2010
Rapamycin is a drug with several important clinical uses. Its complex structure means that total synthesis of this natural product and its analogues is demanding and lengthy. A more expeditious approach is to utilise biosynthesis to enable the generation of otherwise synthetically intractable analogues. In order to achieve this, rules governing biosynthetic precursor substrate preference must be established. Through determining these rules and synthesising and administering suitable substrate precursors, we demonstrate the first generation of fluorinated rapamycin analogues. Here we report the generation of six new fluororapamycins. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.
Wu M.-C.,University of Manchester |
Law B.,University of Manchester |
Wilkinson B.,Biotica Technology Ltd. |
Micklefield J.,University of Manchester
Current Opinion in Biotechnology | Year: 2012
With the advent of next-generation DNA sequencing technologies, the number of microbial genome sequences has increased dramatically, revealing a vast array of new biosynthetic gene clusters. Genomics data provide a tremendous opportunity to discover new natural products, and also to guide the bioengineering of new and existing natural product scaffolds for therapeutic applications. Notably, it is apparent that the vast majority of biosynthetic gene clusters are either silent or produce very low quantities of the corresponding natural products. It is imperative therefore to devise methods for activating unproductive biosynthetic pathways to provide the quantities of natural products needed for further development. Moreover, on the basis of our expanding mechanistic and structural knowledge of biosynthetic assembly-line enzymes, new strategies for re-programming biosynthetic pathways have emerged, resulting in focused libraries of modified products with potentially improved biological properties. In this review we will focus on the latest bioengineering approaches that have been utilised to optimise yields and increase the structural diversity of natural product scaffolds for future clinical applications. © 2012 Elsevier Ltd.
Garcia-Rivera J.A.,Scripps Research Institute |
Bobardt M.,Scripps Research Institute |
Chatterji U.,Scripps Research Institute |
Hopkins S.,SCYNEXIS |
And 4 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2012
Alisporivir is the most advanced host-targeting antiviral cyclophilin (Cyp) inhibitor in phase III studies and has demonstrated a great deal of promise in decreasing hepatitis C virus (HCV) viremia in infected patients. In an attempt to further elucidate the mechanism of action of alisporivir, HCV replicons resistant to the drug were selected. Interestingly, mutations constantly arose in domain II of NS5A. To demonstrate that these mutations are responsible for drug resistance, they were reintroduced into the parental HCV genome, and the resulting mutant viruses were tested for replication in the presence of alisporivir or in the absence of the alisporivir target, CypA. We also examined the effect of the mutations on NS5A binding to itself (oligomerization), CypA, RNA, and NS5B. Importantly, the mutations did not affect any of these interactions. Moreover, the mutations did not preserve NS5A-CypA interactions from alisporivir rupture. NS5A mutations alone render HCV only slightly resistant to alisporivir. In sharp contrast, when multiple NS5A mutations are combined, significant resistance was observed. The introduction of multiple mutations in NS5A significantly restored viral replication in CypA knockdown cells. Interestingly, the combination of NS5A mutations renders HCV resistant to all classes of Cyp inhibitors. This study suggests that a combination of multiple mutations in domain II of NS5A rather than a single mutation is required to render HCV significantly and universally resistant to Cyp inhibitors. This in accordance with in vivo data that suggest that alisporivir is associated with a low potential for development of viral resistance. Copyright © 2012, American Society for Microbiology. All Rights Reserved.
Qu X.,CAS Shanghai Institute of Organic Chemistry |
Jiang N.,CAS Shanghai Institute of Organic Chemistry |
Xu F.,CAS Shanghai Institute of Organic Chemistry |
Shao L.,CAS Shanghai Institute of Organic Chemistry |
And 3 more authors.
Molecular BioSystems | Year: 2011
Sanglifehrin A (SFA), a potent cyclophilin inhibitor produced by Streptomyces flaveolus DSM 9954, bears a unique [5.5] spirolactam moiety conjugated with a 22-membered, highly functionalized macrolide through a linear carbon chain. SFA displays a diverse range of biological activities and offers significant therapeutic potential. However, the structural complexity of SFA poses a tremendous challenge for new analogue development via chemical synthesis. Based on a rational prediction of its biosynthetic origin, herein we report the cloning, sequencing and characterization of the gene cluster responsible for SFA biosynthesis. Analysis of the 92776 bp contiguous DNA region reveals a mixed polyketide synthase (PKS)/non-ribosomal peptide synthetase (NRPS) pathway which includes a variety of unique features for unusual PKS and NRPS building block formation. Our findings suggest that SFA biosynthesis requires a crotonyl-CoA reductase/carboxylase (CCR) for generation of the putative unusual PKS starter unit (2R)-2-ethylmalonamyl-CoA, an iterative type I PKS for the putative atypical extender unit (2S)-2-(2-oxo-butyl)malonyl-CoA and a phenylalanine hydroxylase for the NRPS extender unit (2S)-m-tyrosine. A spontaneous ketalization of significant note, may trigger spirolactam formation in a stereo-selective manner. This study provides a framework for the application of combinatorial biosynthesis methods in order to expand the structural diversity of SFA. © The Royal Society of Chemistry 2011.
Biotica Technology Ltd | Date: 2010-12-15
14-Membered macrolide compounds such as erythromycins are provided with functional groups at the 14- and/or 15-position by providing a 14-membered aglycone template and feeding it to a strain capable of hydroxylating it at the 14 and/or 15 position. The strain may be found by screening, selected from known strains (e.g. Streptomyces eurythermus DSM 40014) or produced by genetically engineering a strain to express a cytochrome P450 enzyme.
BIOTICA TECHNOLOGY Ltd | Date: 2015-03-02
The present invention relates to production of polyketides and other natural products and to libraries of compounds and individual novel compounds. One important area is the isolation and potential use of novel FKBP-ligand analogues and host cells that produce these compounds. The invention is particularly concerned with methods for the efficient transformation of strains that produce FKBP analogues and recombinant cells in which cloned genes or gene cassettes are expressed to generate novel compounds such as polyketide (especially rapamycin) FKBP-ligand analogues, and to processes for their preparation, and to means employed therein (e.g. nucleic acids, vectors, gene cassettes and genetically modified strains).