title: Structural analysis and biosynthetic engineering of a solubility-improved and less-hemolytic nystatin-like polyene in Pseudonocardia autotrophica.
abstract: Polyene antibiotics such as nystatin are a large family of very valuable antifungal polyketide compounds typically produced by soil actinomycetes. Previously, using a polyene cytochrome P450 hydroxylase-specific genome screening strategy, Pseudonocardia autotrophica KCTC9441 was determined to contain an approximately 125.7-kb region of contiguous DNA with a total of 23 open reading frames, which are involved in the biosynthesis and regulation of a structurally unique polyene natural product named NPP. Here, we report the complete structure of NPP, which contains an aglycone identical to nystatin and harbors a unique di-sugar moiety, mycosaminyl-(α1-4)-N-acetyl-glucosamine. A mutant generated by inactivation of a sole glycosyltransferase gene (nppDI) within the npp gene cluster can be complemented in trans either by nppDI-encoded protein or by its nystatin counterpart, NysDI, suggesting that the two sugars might be attached by two different glycosyltransferases. Compared with nystatin (which bears a single sugar moiety), the di-sugar containing NPP exhibits approximately 300-fold higher water solubility and 10-fold reduced hemolytic activity, while retaining about 50% antifungal activity against Candida albicans. These characteristics reveal NPP as a promising candidate for further development into a pharmacokinetically improved, less-cytotoxic polyene antifungal antibiotic.
authors.affiliation: Department of Biological Engineering, Inha University, Incheon 402-751, South Korea.
authors.forename: Mi-Jin
authors.initials: MJ
authors.lastname: Lee
authors.forename: Dekun
authors.initials: D
authors.lastname: Kong
authors.forename: Kyuboem
authors.initials: K
authors.lastname: Han
authors.forename: David H
authors.initials: DH
authors.lastname: Sherman
authors.forename: Linquan
authors.initials: L
authors.lastname: Bai
authors.forename: Zixin
authors.initials: Z
authors.lastname: Deng
authors.forename: Shuangjun
authors.initials: S
authors.lastname: Lin
authors.forename: Eung-Soo
authors.initials: ES
authors.lastname: Kim
mesh_terms: D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D000935:Antifungal Agents / Q000737:chemistry / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D002176:Candida albicans / Q000187:drug effects; D005656:Fungal Proteins / Q000235:genetics; D005818:Genetic Engineering / Q000379:methods*; D006461:Hemolysis; D008826:Microbial Sensitivity Tests; D005810:Multigene Family; D009154:Mutation; D009761:Nystatin / Q000096:biosynthesis / Q000737:chemistry; D011090:Polyenes / Q000737:chemistry / Q000378:metabolism; D012995:Solubility; D013329:Structure-Activity Relationship
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D011090:Polyenes; D009761:Nystatin