Isolation and characterisation of amphotericin B analogues and truncated polyketide intermediates produced by genetic engineering of Streptomyces nodosus.
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.
Murphy
Barry
B
Department of Chemistry, University of Leicester, University Road, Leicester, UK.
Anderson
Katie
K
Borissow
Charles
C
Caffrey
Patrick
P
Griffith
Gerald
G
Hearn
Jessica
J
Ibrahim
Odubunmi
O
Khan
Naseem
N
Lamburn
Natalie
N
Lee
Michael
M
Pugh
Katherine
K
Rawlings
Bernard
B
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*
D001426:Bacterial Proteins; D000666:Amphotericin B