title: Biosynthesis of 3″-demethyl-gentamicin C components by genN disruption strain of Micromonospora echinospora and test their antimicrobial activities in vitro.
abstract: Gentamicin consists primarily of four components, which have different patterns of methylation at C-6' position. The methyl groups have a significant impact on gentamicin antimicrobial activity. Sequence analysis predicted that GenN was a methyltransferase in the gentamicin biosynthetic pathway. To study the function of genN, it was disrupted in Micromonospora echinospora. The genN disruption strains produced 3″-N-demethyl-gentamicin C complex instead of the gentamicin C complex. In this study, 3″-N-demethyl gentamicin C1a was purified from the broth of disruption strain, and its structure was elucidated using MS and NMR. Besides 3″-N-demethyl products corresponding to gentamicin C1a, C2, and C2a, two 3″-N-demethyl products corresponding to gentamicin C1 were detected, which were concluded as C-6' epimers originating from decreased substrate specificity of 6'-N methyltransferase. To explore the effects of 3″-N-methyl on gentamicin antimicrobial activity, antimicrobial activity of these demethyl gentamicin analogues were tested in vitro. 3″-N-Demethyl gentamicin components have identical activity with corresponding components of gentamicin. The results of bioassays showed that the 3″-N-methyl group has little impact on gentamicin activity. However, these highly bioactive compounds afforded a unique opportunity for creating new and high potent aminoglycoside antibiotics.
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China.
authors.forename: Xianpu
authors.initials: X
authors.lastname: Ni
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zong
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China.
authors.forename: Yawen
authors.initials: Y
authors.lastname: Gu
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China.
authors.forename: Miaoling
authors.initials: M
authors.lastname: Huang
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: tianweiww@sina.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Tian
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: xiahz612@sina.com.
authors.forename: Huanzhang
authors.initials: H
authors.lastname: Xia
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004269:DNA, Bacterial / Q000235:genetics; D005285:Fermentation; D005838:Genotype; D005839:Gentamicins / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D053858:Metabolic Networks and Pathways; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism*; D008847:Micromonospora / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D017421:Sequence Analysis
chemical_list: D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D005839:Gentamicins; C100093:gentamicin C; D008780:Methyltransferases
keywords: 3″-N-Demethyl gentamicin C components; Antimicrobial activity; Gene disruption; Methyltransferase