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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.
Production, Isolation and Biological Activity of Nargenicin from Nocardia sp. CS682
Sohng, Jae-Kyung,Yamaguchi, Tokutaro,Seong, Chi-Nam,Baik, Keun-Sik,Park, Seong-Chan,Lee, Hyo-Jeong,Jang, So-Young,Simkhada, Jaya Ram,Yoo, Jin-Cheol 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.10
Culture broth of an actinomycete isolate, Nocardia sp. CS682 showed specifically higher antibacterial activity against methicilin resistant Staphylococcus aureus (MRSA). Purified substance from the organism, CS-682, which is active against MRSA and Micrococcus leuteus, is a $C_{28}H_{37}NO_8$ ($M+H^+$, observed: 516.83) and identified as an unusual macrolide antibiotic, nargenicin. The chemical structure of CS-682 was identified by FT-IR, $^1H$-NMR, $^{13}C$-NMR, and ($^1H-^1H$ and $^1H-^{13}H$) COSY. The anti-MRSA activity of CS-682 was stronger than that of oxacillin, vancomycin, monensin, erythromycin, and spiramycin. Phylogenetic analysis showed that strain CS682 is closely related to Nocardia tenerifensis DSM $44704^T$ (98.7% sequence similarity), followed by N. brasiliensis ATCC $19296^T$ (98.4% sequence similarity). The ability of Nocardia sp. CS682 to produce nargenicin was unique.
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.
Mechanism Study of dTDP-D-Glucose 4,6-Dehydratase: General Base in Active Site Domain
Sohng, Jae-Kyung,Noh, Hyung-Rae,Yoo, Jin-Cheol Korean Society for Biochemistry and Molecular Biol 1999 Journal of biochemistry and molecular biology 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 sterochemical 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.
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.
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.