title: Isolation and characterisation of amphotericin B analogues and truncated polyketide intermediates produced by genetic engineering of Streptomyces nodosus.
abstract: Amphotericin B is a powerful but toxic drug used against fungal infections and leishmaniases. These diseases would be treated more effectively if non-toxic amphotericin derivatives could be produced on a large scale at low cost. Genetic manipulation of the amphotericin B producer, Streptomyces nodosus, has previously led to the detection and partial characterisation of 8-deoxyamphotericin B, 16-descarboxyl-16-methyl-amphotericin B, 15-deoxy-16-descarboxyl-16-methyl-15-oxo-amphotericin B, 7-oxo-amphotericin B and pentaene analogues. Here we report improved production and purification protocols that have allowed detailed chemical analyses of these compounds. The polyketide synthase product 8-deoxy-16-descarboxyl-16-methyl-amphoteronolide B was identified for the first time. In addition, the ketoreductase 10 domain of the polyketide synthase was specifically inactivated by targeted gene replacement. The resulting mutants produced truncated polyketide intermediates as linear polyenyl-pyrones.
authors.affiliation: Department of Chemistry, University of Leicester, University Road, Leicester, UK.
authors.forename: Barry
authors.initials: B
authors.lastname: Murphy
authors.forename: Katie
authors.initials: K
authors.lastname: Anderson
authors.forename: Charles
authors.initials: C
authors.lastname: Borissow
authors.forename: Patrick
authors.initials: P
authors.lastname: Caffrey
authors.forename: Gerald
authors.initials: G
authors.lastname: Griffith
authors.forename: Jessica
authors.initials: J
authors.lastname: Hearn
authors.forename: Odubunmi
authors.initials: O
authors.lastname: Ibrahim
authors.forename: Naseem
authors.initials: N
authors.lastname: Khan
authors.forename: Natalie
authors.initials: N
authors.lastname: Lamburn
authors.forename: Michael
authors.initials: M
authors.lastname: Lee
authors.forename: Katherine
authors.initials: K
authors.lastname: Pugh
authors.forename: Bernard
authors.initials: B
authors.lastname: Rawlings
mesh_terms: D000666:Amphotericin B / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D015202:Protein Engineering; D013302:Streptomyces / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D000666:Amphotericin B