Xylan 분해균주인 Bacillus stearothermophilus의 오탄당 이용

이효선,조쌍구,최용진 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.4

강력한 xylan 분해 토양 분리균인 Bacillus stearothermophilus의 xylan 분해 주 산물인 xylose와 arabinose등의 pentose 이용과 pentose이용에 미치는 glucose와 기타 maltose 및 cellobiose 등의 효과를 분석하였다. 본 균주는 유일 탄소원으로 glucose를 가장 효율적으로 이용하였으며 다음으로 xylose와 ribose와 같은 pentose 그리고 maltose 등의 이당류도 잘 이용하였으나 glycerol은 전혀 이용하지 못하였다. 또한 glucose와 pentose 또는 xylooligomer와의 혼합 탄소원을 첨가했을 때도 B. stearothermophilus는 glucose를 우선적으로 이용하는 순서적 이용(sequential utilization) 현상과 더불어 전형적인 diauxic growth 양상을 나타내었다. 이에 비해 maltose와 pentose 혼합기질의 경우는 동시이용(co-utilization) 현상을 보였고 cellobios와 pentose 혼합물은 순서적 이용, 그리고 xylose와 arabinose의 pentose 혼합 탄소원인 경우는 두 탄소원을 동시에 이용하였다. 이와 같은 B. stearothermophilus의 탄소원 이용 특성은 glucose 대사관련 주요 효소인 hexokinase의 구성적 생산(constitutive production)과 이에 반한 ^D-xylose isomerase, ^D-xylulokinase 및 ^L-arabinose isomerase 등의 pentose 대사 주 관련 효소의 유도 생산(induced production)과 관계되는 효소 생산 조절 기작 내지는 inducer exclusion 현상을 비롯한 catabolite regulatory mechanism에 기인하는 것으로 설명할 수 있었다. Bacillus stearothermophilus, a potent xylanolytic bacterium isolated from soil, was tested for the strain's strategies of pentose utilization and the evidence of substreate preferences. The strain metabolized glucose, xylose, ribose, maltose, cellobiose, sucrose, arabinose and xylitol. The efficacy of the sugars as a carbon and energy source in this strain was of the order named above. The organism, however, could not grow on glycerol as a sole growth substrate. During cultivation on a mixture of glucose and xylose or arabinose, the major hydrolytic products of xylan, B. stearothermophilus displayed classical diauxic growth in which glucose was utilized during the first phase. On the other hand, the pentose utilization was prevented immediately upon addition of glucose. Cellobiose was preferred over xylose or arabinose. In contrast, maltose and pentose were co-utilized, and also no preference on between xylose and arabinose. Enzymatic studies indicated that B. stearothermophilus possessed constitutive hexokinase, a key enzyme of the glucose metabolic system. While, the production of ^D-xylose isomerase, ^D-xylulokinase and ^D-arabinose isomerase essential for pentose phosphate pathway were induced by xylose, xylan, and xylitol but repressed by glucose. Taken together, the results suggested that the sequential utilization of B. stearothermophilus would be mediated by catabolite regulatory mechanisms such as catabolite inhibition or inducer exclusion.

플라보노이드의 세포 신호전달 조절

이응룡,강근호,강용진,김우열,최혜연,김봉우,정효순,조쌍구 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

Many studies revealed the neuroprotective, cardioprotective, and chemopreventive actions of dietary flavonoids. The plausible mechanistic interpretation of the various effects of flavonoids was concentrated on the anti-oxidant or free radical-scavenging properties of these phytochernicals, both in model systems and under in vivo conditions. While there has been a major focus on the anti-oxidant properties. there is an emerging view that flavonoids and their in vivo metabolites. do not act as conventional hydrogen-donating anti-oxidants. but they may exert regulatory functions in cells through actions at protein kinase or lipid kinase signaling pathways. Flavonoids and more recently their metabolites. have been reported to act at phosphoinositide 3-kinase(PI 3-kinase). Akt/protein kinase B(Akt/PKB), protein kinase C (PKC), mitogen activated protein kinase(MAP kinase), and various tyrosine kinases signaling cascades. Inhibitory or stimulatory actions at these pathways are likely to affect cellular function profoundly by altering the phosphorylation state of target molecules and by modulating gene expression. A clear understanding of the mechanisms of action of flavonoids, either as anti-oxidants or modulators of cellular signaling pathways, and the influence of their metabolism on these properties are key to the evaluation of these potent biomolecules as anti-cancer agents, cardio-protectants, and inhibitors of neurodegeneration.

α1,3-Gal Knock out Pigs Increases N-Glycolylneuraminic Acids

Jong-Yi Park,Mi-Ryung Park,Hong-Thuy Bui,Deug-Nam Kwon,Min-Hui Kang,Mihye Oh,Jae-Woong Han,Ssang-Goo Cho1,Chankyu Park,Hosup Shim,Hye-Min Kim,Man-Jong Kang,Jin-Ki Park,Jeong-Woong Lee,Kyung-Kwang Lee 한국동물번식학회 2012 Reproductive & Developmental Biology(Supplement) Vol.36 No.2s

In this study, we examined whether Hanganutziu-Deicher (H-D) antigens are important as an immunogenic non-a1,3-galactose (Gal) epitope in pigs with a disrupted a1,3- galactosyltransferase gene. The targeting efficiency of the AO blood genotype was achieved (2.2%) in pig fibroblast cells. A total of 1800 somatic cell nuclear transfer (SCNT) embryos were transferred to 10 recipients. One recipient developed to term and naturally delivered two piglets. The a1,3-galactosyltransferase activity in lung, liver, spleen, and testis of heterozygote a1,3-galactosyltransferase gene knockout (GalT-KO) pigs was significantly decreased, whereas brain and heart showed very low decreasing levels of a1,3- galactosyltransferase activity when compared to those of control. Enzyme-linked lectinosorbent assay showed that the heterozygote GalT-KO pig had more sialyla2,6- and sialyla2,3- linked glycan than the control. Furthermore, the heart, liver, and kidney of the heterozygote GalT-KO pig had a higher N-glycolylneuraminic acid (Neu5Gc) content than the control, whereas the lung of the heterozygote GalT-KO pig had Neu5Gc content similar to the control. Collectively, the data strongly indicated that Neu5Gc is a more critical xenoantigen to overcoming the next acute immune rejection in pig to human xenotransplantation.

Regulation of the ROS Production and Apoptosis by BI-1/TEGT, an Ancient Membrane Protein

CHO, Ssang-Goo 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

Nucleotide Sequence Analysis of an Endo-Xylanase Gene(xynA) from Bacillus stearothermophilus

Cho, Ssang Goo,Choi, Yong Jin 한국미생물 · 생명공학회 1995 Journal of microbiology and biotechnology Vol.5 No.3

A gene (xynA) encoding the endo-xylanase (E.C.3.2.1.8) from Bacillus stearothermophilus was cloned in E. coli, and its complete nucleotide sequence was determined. The xynA gene consists of a 636 base pairs open reading frame coding for a protein of 212 amino acids with a deduced molecular weight of 23,283 Da. A putative signal sequence of 27 amino acid residues shows the features comparable with the Bacillus signal sequences; namely, the signal contains a positively charged region close to the N-terminus followed by a long hydrophobic string. The coding sequence is preceded by a possible ribosome binding site with a free energy value of -16.6 ㎉/㏖ and the transcription initiation signals are located further upstream. The translation termination codon (TAA) at the 3' end of the coding sequence is followed by two palindrome sequences, one of which is thought to act as a terminator. The xynA gene has a high GC content, especially in the wobble position of codons (64%). Comparison of the primary protein sequence with those of other xylanases shows a high homology to the xylanases belonging to family G.

Apoptotic Signaling Pathways: Caspases and Stress-Activated Protein Kinases

Cho, Ssang-Goo,Choi, Eui-Ju Korean Society for Biochemistry and Molecular Biol 2002 Journal of biochemistry and molecular biology Vol.35 No.1

Apoptotic cell death is an active process mediated by various signaling pathways, which include the caspase cascade and the stress-activated protein kinase pathways. The caspase cascade is activated by two distinct routes: one from cell surface and the other from mitochondria. Activation of the route from cell surface requires the cellular components that include membrane receptors, adaptor proteins such as TRADD and FADD, and caspase-8, while activation of the other from mitochondria requires Apaf-1, caspase-9, and cytosolic cytochrome c. On the other hand, persistent stimulation of the stress-activated protein kinase pathway is also shown to mediate apoptosis in many cell types. Gene-targeting studies with jnk- or jip-null mice, in particular, strongly suggest that this signaling pathway plays a pivotal role in the cellular machinery for apoptosis.

TIP49b, a Regulator of Activating Transcription Factor 2 Response to Stress and DNA Damage

Cho, Ssang-Goo,Anindita Bhoumik,Ze'ev Ronai 이화여자대학교 세포신호전달연구센터 2002 고사리 세포신호전달 심포지움 Vol. No.4

Activating transcription factor-2(ATF2/CRE-BP1) is a member of the ATF-CREB family of transcription factors, which has been implicated in growth control, cell cycle progression, differentiation and transformation. Upon exposure to stress or DNA damage, JNK/p38 kinases phosphorylate T-69 and T-71, alleviating intrinsic inhibition and rendering ATF2 transcriptionally active. As a leucine zipper transcription factor, ATF2 binds an 8-bp response element(CRE/URE; 5-TGACGTCA-3; 61), as a homodimer or as a heterodimer with other members of the ATF family, as well as the Jun/Fos family of transcription factors. Although ATF-2 has been implicated in the transcriptional control of various stress-responsive genes, including c-jun, interferon-b, TGFb, and TNFa, our understanding of the biological functions of ATF2 is limited. A yeast two-hybrid screen identified TBP-interacting protein 49b(TIP49b), a component of the INO80 chromatin-remodeling complex, as a novel ATF2-interacting protein. TIP49b's association with ATF2 is phosphorylation dependent and requires amino acids 150 to 248 of ATF2(ATF2^(150-248)), which are implicated in intramolecular inhibition of ATF2 transcriptional activities. Forced expression of TIP49b efficiently attenuated ATF2 transcriptional activities under normal growth conditions as well as after UV treatment, ionizing irradiation, or activation of p38kinase, all of which induced ATF2 phosphorylation and increased TIP49b-ATF2 association. Constitutive expression of ATF2^(150-248) peptide outcompeted TIP49b interaction with ATF2 and alleviated the suppression of ATF2 transcriptional activities. Expression of ATF2^(150-248) in fibroblasts or melanoma but not in ATF2-null cells caused a profound G2M arrest and increased degree of apoptosis following irradiation. The interaction between ATF2 and TIP49b constitutes a novel mechanism that serves to limit ATF2 transcriptional activities and highlights the central role of ATF2 in the control of the cell cycle and apoptosis in response to stress and DNA damage.

Efficient transfection of IMUP genes into stem cells by magnetofection leads to stimulated proliferation and distinctive differentiation pattern

Ssang-Goo Cho 한국실험동물학회 2008 한국실험동물학회 학술발표대회 논문집 Vol.2008 No.-

Overproduction , Purification , and Characterization of Bacillus stearothermophilus Endo - xylanase A ( XynA )

( Ssang Goo Cho,Jung Han Suh,Yong Jin Choi ) 한국미생물생명공학회 1996 Journal of microbiology and biotechnology Vol.6 No.2

Regulation of β - Xylosidase ( XylA ) Synthesis in Bacillus stearothermophilus

( SSANG GOO CHO,YONG JIN CHOI ) 한국미생물생명공학회 1998 Journal of microbiology and biotechnology Vol.8 No.1