Streptomyces sp. GCA0001로 부터의 신규 항생물질 Cystocin의 구조분석, 생물활성 및 유도체제조

김자용,이희찬,우진석,송재경 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

본 발명의 Puromycin 유도체인 Cystocin 화합물은 유기 합성에 의해 제조된 물질이 아니라 방선균계열의 신균주인 Streptomyces sp GCA0001로부터 추출된 신규 물질로서, 항박테리아, 항종양 및 항바이러스 활성 등의 생물학적 미생물 활성면에서 종래의 Puromycin 화합물에 비해 현저히 뛰어난 효과를 지니고 있고 Streptomyces sp GCA0001로부터 추출, 분리 및 정제 과정을 통해 제조된 자연의 선택의 과정을 거친 화합물이므로, Puromycin을 대체할 수 있는 획기적인 물질로 볼 수 있다. Cystocin, a derivative of Puromycin, is a new material derived from Streptomyces sp GCA0001, new strain of Actinomycetes spiecies.This compound has outstanding biological activities in anti-bacteria, anti-tumor and anti-virus than former Puromycin compounds.And it is chosen by natural selection processing through extraction, isolation and purification from, so it may replace old Puromycins in most applications.

Glycosylation of free sterol by whole-cell bioconversion in E. coli

Jae Kyung Sohng,Jae Kyung Sohng 한국당과학회 2011 한국당과학회 학술대회 Vol.2011 No.1

Steryl glucosides play important roles in many physiological and biochemical process in organism such as the heat shock, enhancement of immunological system, etc. The alignment of a putative sterol glucosides isolated from S. tropica CNB-440 has been shown 34%, 42% and 57% in homology with the corresponding ones from Arabidopis thaliana, Avena sativa and Salinispora arenicola CNS-205, respectively. Engineered E. coli host-high level production of the UDP-glucose was used for whole-cell bioconversion of free sterol (cholesterol and β-sistosterol) and the production of glycosylated product was only detected with β-sitosterol as substrate.

Glycosylation of flavonoid in genetic engineered E. coli

Jae Kyung Sohng 한국당과학회 2009 한국당과학회 학술대회 Vol.2009 No.1

Flavonoids are a group of polyphenolic compounds that have been recognized as important due to their physiological and pharmacological roles and their health benefits. Glycosylation of flavonoids has a wide range of effects on flavonoid solubility, stability, and bioavailability. We previously generated the E. coli BL21 (DE3) Δpgi host by deleting the glucose-phosphate isomerase (Pgi) gene in E. coli BL21 (DE3). This host was further engineered for whole-cell biotransformation by integration of galU from E. coli K12, and expression of calS8 (UDP-glucose dehydrogenase) and calS9 (UDP-glucuronic acid decarboxylase) from Micromonospora echinospora spp. calichensis and arGt-4 (7-O-glycosyltransferase) from Arabidopsis thaliana to form E. coli (US89Gt-4), which is expected to produce glycosylated flavonoids. To test the designed system, the engineered host was fed naringenin as a substrate, and naringenin 7-O-xyloside, a glycosylated naringenin product, was detected. Product formation was verified by HPLC-LC/MS and ESI-MS/MS analyses. The reconstructed host can be applied for the production of various classes of glycosylated flavonoids. A whole-cell biotransformation system was designed in E. coli BL21 (DE3) Δpgi by integrating galU (glucose-1-phosphate uridylyltransferase) from E. coli K12, expressing calS8 (UDP-D-glucose dehydrogenase) and calS9 (UDP-D-glucuronic acid decarboxylase) from Micromonospora echinospora spp. calichensis and arGt-3 (3-O-glycosyltransferase) from Arabidopsis thaliana to form an engineered host, E. coli (US89Gt-3), for the production of glycosylated flavonoids when exogenously fed with flavonoids. To verify the system, quercetin was fed and a glycosylated product, quercetin 3-O-glucuronide, was produced but unable to produce quercetin 3-O-xyloside.

Mechanism Study of dTDP-D-Glucose 4,6-Dehydratase: General Base in Active Site Domain

Sohng, Jae-Kyung,Noh, Hyung-Rae,Yoo, Jin-Cheol The Korea Science and Technology Center 1999 BMB Reports Vol.32 No.4

dTDP-D-glucose 4,6-dehydratase as an oxidoreductase catalyzes the conversion of dTDP-D-glucose to dTDP-4-keto-6-deoxy-D-glucose, which is essential for the formation of 6-deoxysugars. dTDP-D-glucose 4,6-dehydratase shows remarkable stereochemical convergence in which displacement of the C-6 hydroxyl group by a C-4 hydrogen proceeds intramolecularly with inversion of configuration. The reaction mechanism is known to be oxidation, dehydration, and reduction by bases mediating proton transfer and NAD? cofactor. In this study, the bases in the active site domain are proposed to be His-79 and His-300 from a comparison of the peptides of the dehydratase and UDP-D-glucose epimerase. His-79 and His-300 were mutated to prepare the mutants H79L (mutation of histidine to leucine at the 79th amino acid) and H300A (mutation of histidine to alanine at the 300th amino acid) by site-directed mutagenesis. The H79L protein was inactive, showing that His-79 participates in the reaction mechanism.

Method for Cloning Biosynthetic Genes of Secondary Metabolites Including Deoxysugar from Actinomycetes

Sohng, Jae-Kyung,Oh, Tae-Jin,Kim, Chun-Gyu Korean Society for Biochemistry and Molecular Biol 1998 Journal of biochemistry and molecular biology Vol.31 No.5

Many antibiotics contain partially deoxygenated sugar components that are usually essential for biological activity, affinity, structural stability, and solubility of antibiotics. Gene probes of the biosynthetic genes related with the deoxysugar were obtained from PCR. Primers were designed from the conserved peptide sequences of the known dTDP-D-glucose 4,6-dehydratases, which are the key step enzymes in the biosynthesis of deoxysugar. The primers were applied to amplify parts of dehydratase genes to 27 actinomycetes that produce the metabolites containing deoxysugar as structural constituents. About 180 and 340 bp DNA fragments from all of the actinomycetes were produced by PCR and analyzed by Southern blot and DNA sequencing. The PCR products were used as gene probes to clone the biosynthetic gene clusters for the antibiotic mithramycin, rubradirin, spectinomycin, and elaiophyrin. This method should allow for detecting of the biosynthetic gene clusters of a vast array of secondary metabolites isolated from actinomycetes because of the widespread existence of deoxysugar constituents in secondary metabolites.

Identification of a Gene Cluster of Biosynthetic Genes of Rubradirin Substructures in S. achromogenes var. rubradiris NRRL3061

Sohng, Jae-Kyung,Oh, Tae-Jun,Lee, Jung-Joon,Kim, Chun-Gyu Korean Society of Molecular Biology 1997 Molecules and cells Vol.7 No.5

Cloning, Sequencing and Expression of dTDP-D-Glucose 4,6-Dehydratase Gene from Streptomyces antibioticus Tu¨99, a Producer of Chlorothricin

Sohng, Jae Kyung,Yoo, Jin-cheol 朝鮮大學校 1997 藥學硏究誌 Vol.18 No.2

DNA fragments, homologous to the dTDP-Dgiucose 4,6-dehydratase gene, obtained from the genomic DNA of Streptomyces antibioticus Tu¨99,a producer of the unusual macrolide antibiotic chlorothricin, were cloned and aequenced. This dehydratase gene was designated as oxil. The coding region of the oxil gene is composed of 987 bp, and analysis of the DNA sequence data reveals sequences for the gene products of 329 amino acids(molecular weight of 36.037). The deduced amino acids are 59% identical to the StrE, dTDP-D-glucose 4,6-dehydratase from the Streptomycin pathway. The oxil's function was examined by expressing it in E. coil using the T7 RNA polymerase/promoter system(pRSET) to produce an active fusion protein including a his tag. This enzyme shows apecificity of substrate, specific only to dTDP-D-glucose.

Microbial Production of Natural and Non-natural Products: Flavonoids and Anthraquinone

( Jae Kyung Sohng ) 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Development of microbial cell factories via metabolic engineering, protein engineering and synthetic biology has revolutionized the maximum use of microbial systems for biosynthesis and modification of valuable flavonoids and anthraquinone. From a single enzyme expression to complex metabolic pathway, it has been possible to manipulate strains such as Escherichia coli and Streptomyces for target based modification of compounds to industrial level in laboratory. Biotransformation, a biotechnological approach can be applied to structurally modify and generate library of natural products such as flavonoid and anthraquinone derivatives. Basically E. coli has been engineered by expressing secondary metabolites post modifying enzymes such as glycosyltransferases (GTs) and O-methyltransferases (OMTs) in particular to generate the natural and non-natural flavonol and anthaquinone derivatives.

Biosynthesis of Chlorothricin produced by Streptomyces antibioticus Tu99

Sohng, Jae Kyung 선문대학교 첨단과학기술연구소 1997 첨단과학기술연구소 논문집 Vol.2 No.-

This paper considers a security framework for geographic information System(GIS). The GIS is an information system for supporting fast decision associated spacial problems and the system has a role of infra structure of the information system. The security is also one of the major technology for information system. However, researches on secure GIS are presented little and this paper considers the secure GIS. This paper suggest a framework for the secure GIS based on derived requirements on the secure system. Analysis on security for a serial, parallel and hierarchical secure system is also added.

Gene Cloning and Analysis of Biosynthetic Gene of Spectinomycin

Sohng, Jae-Kyung,Oh, Tae-Jin,Liou, Kwang-Kyoung,Lee, Hei-Chan 선문대학교 첨단과학기술연구소 2001 첨단과학기술연구소 논문집 Vol.5 No.-

A biosynthetic gene cluster involved in the production of spectinomyein was cloned from Streptomyes spectabilis cosmid library with dTDP-glucose 4,6-dehydratase and amnino transferase gene probes. The DNA probes were obtained from S. speciabilis genome with primers based on consensus sequences of known enzymes using a polymerase chain reaction. One of the cloned cosmids, pSPM8, contained the homologue of the dTDP-glucose 4,6-dehydratase and amino transferase gene. The DNA sequence analysis reveals four open reading frames and one incomplete reading frame. The putative orf1 protein reveals 29% amino acid sequence homology of putative myo-inositol-2-dehydrogenase from Vibrio anguillamm. The orf2 is about 46% homologous to putative myo-inositol-1-monophosphotase of Mycobacterium leprae. The orf3 showed strong homology (67.4%) to putative export protein (spcT) from s. flavopersicus. The amino acid sequel deduced from orf4 showed a high similarity (70.8%) to a spectinomycin resistance gene (spcN) from S. flavopersicus. Expression of orf4 in E. coli BL21 showed the spectinomycin resistance.