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Discovery of parallel pathways of kanamycin biosynthesis allows antibiotic manipulation
Park, Je Won,Park, Sung Ryeol,Nepal, Keshav Kumar,Han, Ah Reum,Ban, Yeon Hee,Yoo, Young Ji,Kim, Eun Ji,Kim, Eui Min,Kim, Dooil,Sohng, Jae Kyung,Yoon, Yeo Joon Nature Publishing Group, a division of Macmillan P 2011 Nature chemical biology Vol.7 No.11
Kanamycin is one of the most widely used antibiotics, yet its biosynthetic pathway remains unclear. Current proposals suggest that the kanamycin biosynthetic products are linearly related via single enzymatic transformations. To explore this system, we have reconstructed the entire biosynthetic pathway through the heterologous expression of combinations of putative biosynthetic genes from Streptomyces kanamyceticus in the non??aminoglycoside-producing Streptomyces venezuelae. Unexpectedly, we discovered that the biosynthetic pathway contains an early branch point, governed by the substrate promiscuity of a glycosyltransferase, that leads to the formation of two parallel pathways in which early intermediates are further modified. Glycosyltransferase exchange can alter flux through these two parallel pathways, and the addition of other biosynthetic enzymes can be used to synthesize known and new highly active antibiotics. These results complete our understanding of kanamycin biosynthesis and demonstrate the potential of pathway engineering for direct in vivo production of clinically useful antibiotics and more robust aminoglycosides.
Mass production of 2,3-siallylactose by bio-conversion
Dae Hee Kim,Yoon Joon Sik,Sun Youp Kang,Won Min Seo,Sang Hee Shim,Ji Young Yang,Jin Suk Woo,Kyoung-soon Jang,Byung-Gee Kim,Jae Kyung Sohng 한국당과학회 2008 한국당과학회 학술대회 Vol.2008 No.1
Sialylated sugar chains are present at the cell surface of various animal species. Due to their position, they are thought to serve important roles in a large variety of biological functions such as cell–cell and cell–substrate interactions, bacterial and virus adhesion, and protein targeting. We present a bio-conversion process for the conversion of lactose, N-acetyl- glucosamine and CMP into 2,3-sialyllactose with six enzymes. This process consists of two steps; the first step is from N-acetyl-glucosamine and CMP to CMP-neuraminic acid with five enzymes (GlcNAc-2-epimerase, NeuAc aldolase, CMP kinase, acetate kinase and CMP-NeuAc synthetase) including ATP recycle system to yield over 95% by one-pot reaction and the second step is from lactose and CMP-neuraminic acid with sialyltransferase to yield over 90%. The second step can apply to synthesize the various sialyllactose (sialyloligosaccharide) depend on acceptors (lactose and N- acetyl-lactosamine) and sialyltransferase (2,3-sialyltransferase or 2,6- sialyltransferase).
Chaudhary, Amit Kumar,Park, Je Won,Yoon, Yeo Joon,Kim, Byung-Gee,Sohng, Jae Kyung Kluwer Academic Publishers 2013 Biotechnology letters. Vol.35 No.2
<P>Various approaches for monocistronic constructions of genetic circuits have been designed for metabolite production but there has been no attempt to apply such methodology for aminoglycosides biosynthesis. Here, a simple and commercially available bio-part, despite the current trend focusing on the standardized BioBricks bio-parts available in the registry, is used. A 181-bp nucleotide fragment was designed for the efficient construction of an expression vector for monocistronic assembly of genes. Furthermore, a single vector with multi-monocistronic assembled genes for 2-deoxystreptamine (2-DOS) synthesis was constructed for production in engineered Escherichia coli. The working efficiency of model vector was concluded by reporter assay whereas the expressions of biosynthesis genes were confirmed by RT-PCR and SDS-PAGE. Production of 2-DOS was confirmed by TLC, LC-ELSD, and ESI-MS/MS.</P>
Park, Sung Ryeol,Park, Je Won,Ban, Yeon Hee,Sohng, Jae Kyung,Yoon, Yeo Joon The Royal Society of Chemistry 2013 Natural product reports Vol.30 No.1
<P>Covering: 2007 to September 2012</P><P>The 2-deoxystreptamine-containing aminoglycosides, such as neomycin, kanamycin and gentamicin, are an important class of antibiotics. A detailed understanding of the complete biosynthetic pathway of aminoglycosides and their biosynthetic enzymes will allow us to not only generate more robust antibiotic agents or drugs with other altered biological activities, but also to produce clinically important semi-synthetic antibiotics by direct fermentation. This <I>Highlight</I> focuses on recent advances in the characterization of their biosynthetic enzymes and pathway as well as some chemo-enzymatic and metabolic engineering approaches for the biological production of natural, semi-synthetic, and novel aminoglycosides.</P> <P>Graphic Abstract</P><P>This <I>Highlight</I> covers recent advances in the characterization of biosynthetic enzymes and pathway for 2-deoxystreptamine-containing aminoglycosides as well as some chemo-enzymatic and metabolic engineering approaches for the production of natural, semi-synthetic, and novel aminoglycosides. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2np20092a'> </P>
( Nguyen Lan Huong ),( Nguyen Huu Hoang ),( Anil Shrestha ),( Jae Kyung Sohng ),( Yeo Joon Yoon ),( Je Won Park ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.1
A biotransformation approach using microbes as biocatalysts can be an efficient tool for the targeted modification of existing antibiotic chemical scaffolds to create previously uncharacterized therapeutic agents. By employing a recombinant Streptomyces venezuelae strain as a microbial catalyst, a reduced macrolide, 10,11-dihydrorosamicin, was created from rosamicin macrolide. Its chemical structure was spectroscopically elucidated, and the new rosamicin analog showed 2-4-fold higher antibacterial activity against two strains of methicillin-resistant Staphylococcus aureus compared with its parent rosamicin. This kind of biocatalytic approach is able to expand existing antibiotic entities and can also provide more diverse therapeutic resources.
단 복결정 X 선 회절 방법에 의한 CdTe, CdZnTe 웨이퍼의 결정성 분석
이태석,김재묵,서상희,금동화,송원준,임성욱 대한금속재료학회(대한금속학회) 1991 대한금속·재료학회지 Vol.29 No.10
The crystallinity of CdTe and CdZnTe grown by Bridgman method were evaluated using a double crystal diffraction technique. The FWHM of the rocking curve was compared with the etch-pit density. FWHM increased with the increase of etch-pit density, the increasing rate depending on the density and distribution of etch-pits.