• 한국환경보건학회지
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• 제30권3호
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• pp.230-238
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• 2004

The adverse health effects of a number of environment pollutions are related to the formation of free radicals. Induction of antioxidant defensive system in the response to an oxidative attack is an essential element of the cell to survive. CYP2E1 is easily induced by organic solvents and induces continuous formation of reactive oxygen species (ROS). ${\gamma}$-Glutamyltranspeptidase (${\gamma}$GT) plays an important role in glutathione metabolism and xenobiotic detoxification. To evaluate the characteristic of oxidative stress which induces GGT expression and to understand human antioxidant defensive response against oxidative stress induced by CYP2E1, we studied regulation of ${\gamma}$GT enzyme expression in response to various oxidative stresses in human HepG2 cells. The ${\gamma}$GT activity was not modified after exposure of acute oxidative stress inducing agents (ferric nitrilotriacetate, cumene hydroperoxide, ADP-Fe, O-tetradecanoylphorbol-13-acetate, tumor necrosis factor-alpha). To induce continuous exposure of cells to ROS, HepG2 cells were transfected by human CYP2E1 gene transiently. The CYP2E1 activity was verified with chlorzoxazone hydroxylation. Transfection of CYP2E1 showed continuous 60% increase in intracellular ROS and 240 % increase in microsomal ROS. CYP2E1 overexpressing cells showed increased ${\gamma}$GT activity (2.5-fold). The observed enhancement of ${\gamma}$GT activity correlated with a significant increase of ${\gamma}$GT mRNA (2.1-fold). Treatment with antioxidant strongly prevented the increase in ${\gamma}$GT activity. The CYP2E1 overexpression did not modify toxicity index and increased glutathione levels. These results show that continuous exposure of cells to ROS produced by CYP2E1 up-regulates ${\gamma}$GT; This may be one of the adaptive antioxidant responses of cells to oxidative insult. Present study also suggests that the induction of ${\gamma}$GT could be used as a marker of oxidative stress induced by exposure to organic solvents.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.467-472
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• 2013

Helicobacter pylori increased the ${\gamma}$-glutamyltranspeptidase (GGT) production under low-pH (maximal at pH 4) and appropriate $pCO_2$ conditions, while the production of GGT mRNA correlated with increased total enzyme activity. At pH 4, the bacterium augmented enzyme production in the presence of glutamine (~10 mM) in the medium, which predominantly occurred after a 6-min time-lag. Monovalent salts such as NaCl or $NH_4Cl$ facilitated enzymatic activation in acidic solutions of approximately pH 4.5. In addition, glutathione's ${\gamma}$-glutamyl moiety cysteinylglycine appeared to be taken up readily by the intact H. pylori, but not by the one pretreated with a potent GGT inhibitor, acivicin, suggesting that the GGT may partake in glutathione uptake by the cell.

• 농업과학연구
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• 제34권2호
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• pp.161-170
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• 2007

Poly($\gamma$-glutamic acid) 및 levan의 생성균주로 알려진 Bacillus subtilis BS 62의 $\gamma$-GTP(ggt) 유전자를 해석하기 위하여 PCR 반응에 의해 BS 62의 염색체 DNA로부터 약 2.5 kb의 $\gamma$-GTP(ggt) 유전자 분획을 얻어 그 PCR 산물의 염기서열을 분석하여 기왕에 보고된 기타의 ggt 유전자와 비교 분석한 결과, B. subtilis $\gamma$-GTP 유전자(BSU49358)와 98%의 높은 상동성을 보였으며, Pseudomonas sp. A14(S63255)와는 37%, 방선균인 Streptomyces avermitils(AP005028)의 게놈 DNA와는 38%의 상동성을 나타냈다. BS 62의 $\gamma$-GTP 유전자의 open reading frame은 587개의 amino acid로 구성된 polypeptide의 것으로 해석되었으며, N-terminal의 28개 아미노산은 B. subtilis 펩타이드의 전형적인 형태를 보였고, 전형적인 리보솜의 부착부위는 개시코돈 ATG의 위쪽 7번에서 12번 염기(AGGAGG)에 위치하였고, 그리고 종지코돈 다음에서는 stem-loop 구조, ORF의 위쪽 약 50 bp 지점에서는 catabolite-responsive element가 발견되었다. 또한 B. subtilis 효소의 촉매자리로 추정되는 467번 잔기는 threonine으로서, 다른 박테리아의 serine, 포유동물의 cysteine과는 구별되는 것이었다.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.59-65
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• 2005

Poly-${\gamma}$-glutamic acid (PGA) is an unusual anionic polypeptide and has great potential as an environmentally and industrially significant biodegradable material. A new ${\gamma}$-PGA producer, Bacillus mesentericus MJM1, with high production capacity was isolated from Korean domestic Chungkuckjang bean paste. It produced ${\gamma}$-PGA at the level of 10 g/l in suitable media. The viscosities of 5% initially extracted mucin and purified ${\gamma}$-PGA solutions were 660 cps and 600 cps, respectively. The produced ${\gamma}$-PGA polymer consisted of 2,000 glutamic acid residues with even proportion of L and D types with molecular mass of about 200- 300 kDa. Bacillus mesentericus MJM1 displayed ${\gamma}$-glutamyltranspeptidase (${\gamma}$-GTP) activity that is known to play a key role in ${\gamma}$-PGA biosynthesis. The ${\gamma}$-GTP coding region was located on the plasmid of 5.8 kb. The plasmid, named pMMH1, is a rolling-circle replication (RCR) plasmid and additionally contained a replication origin and type I signal peptidase (sipP) coding region.

• Applied Biological Chemistry
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• 제42권2호
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• pp.91-98
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• 1999

단엽콩, 단백콩, 광안콩, 푸른콩, 만리콩, 신팔달콩 2호, 진품콩, 황금콩 등 콩 8품종의 청국장 가공적성을 구명하기 위하여 원료 콩과 콩 품종별 제조 청국장의 이화학적 관능적 특성을 조사하였다 원료 콩의 이화학적 특성중 콩의 증자조건에 영향을 미치는 종피율과 수화팽윤력, 발효관여 균주인 Bacillus subtilis의 생육에 유리한 fructose, glucose, sucrose 등의 유리당 함량, 그리고 청국장 제품의 경도, 청국장 특유의 점질물 생성과 관련이 있는 ${\gamma}-glutamyltranspeptidase({\gamma}-GTP)$의 활성 및 청국장의 맛을 좌우하는 유리아미노산 아미노태 질소의 함량을 고려하였을 때 신팔달콩 2호와 단엽콩이 청국장 제조용 원료콩으로서 가장 적합한 것으로 나타났다.

• Journal of Ginseng Research
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• 제37권2호
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• pp.194-200
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• 2013

Korean red ginseng (KRG) is prepared by the process of steaming the roots of Panax ginseng. In this study, the feeding effects of KRG-water extract (KRGE) on ethanol-induced liver damage were elucidated by measuring serum biomarkers in rats. Serum ${\gamma}$-glutamyltranspeptidase (g-GT) activity and the concentration of malondialdehyde (MDA) were significantly increased by short-term and long-term ethanol treatment in rats, whereas the activities of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) did not respond. Pretreatment with KRGE maintained the activity of serum GPT, and the MDA concentration induced by short-term ethanol ingestion remained within the normal range. However, co-feeding of KRGE to rats decreased the concentration of MDA but failed to modulate the serum ${\gamma}$-GT activity induced by long-term ethanol treatment. Our studies suggest that in rats, it appears that KRGE does not sufficiently reverse the physiological response evoked by long-term ethanol ingestion to maintain normal conditions, in view of the serum biomarker ${\gamma}$-GT, regardless of KRGE's favorable antioxidant activity.

• 한국식품과학회지
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• 제49권6호
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• pp.610-616
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• 2017

본 연구를 통해 BAGGT를 재조합 B. subtilis를 이용하여 대량 생산하기 위하여 유전자 클로닝, 발현 시스템 구축 및 배지 최적화를 진행하였다. 이중프로모터 시스템을 이용하여 야생형 균주에 비해 42배 효소 생산성이 향상된 발현 시스템을 구축하였다. 또한 PBD 분석을 통해 당밀과 CSL이 재조합 B. subtilis 시스템에서 BAGGT의 생산성에 큰 영향을 주는 인자임을 확인하였으며, 염류의 첨가에 의한 효소 생산성 증대 효과는 미비하거나 부정적이었다. 탄소원으로 당밀을 선택하고 고가의 질소원인 트립톤을 저가의 CSL로 교체한 후 CCD 분석을 통해서 결정된 최적배지 사용 시 최적화 이전의 LB 배지 대비 4.3배의 생산성 증대를 이루었으며, 이는 LB 배지에서 야생형 균주의 BAGGT 생산성 대비 180배의 효소 생산성 개선에 해당하였다. 본 연구를 통해 식품용 효소로서 BAGGT의 대량생산을 위한 공정을 구축하였으며, 이후 정미성 소재 생산에 활용할 수 있을 것으로 기대한다.

• International Journal of Oral Biology
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• 제46권3호
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• pp.127-133
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• 2021

We previously showed that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, in Bacillus subtilis acts as a virulence factor for osteoclastogenesis via the RANKL-dependent pathway. Hence, it can be hypothesized that GGT of periodontopathic bacteria acts as a virulence factor in bone destruction. Because Fusobacterium nucleatum, which is a periodontopathic pathogen, has GGT with a primary structure similar to that of B. subtilis GGT (37.7% identify), the bone-resorbing activity of F. nucleatum GGT was examined here. Recombinant GGT (rGGT) of F. nucleatum was expressed in Escherichia coli and purified using the His tag of rGGT. F. nucleatum rGGT (Fn rGGT) was expressed as a precursor of GGT, and then processed to a heavy subunit and a light subunit, which is characteristic of general GGTs, including the human and B. subtilis enzymes. Osteoclastogenesis was achieved in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. Fn rGGT induced osteoclastogenesis to a level similar to that of B. subtilis rGGT; furthermore, osteoclastogenesis was induced in a dose-dependent manner. These results suggest that F. nucleatum GGT possesses a virulent bone-resorbing activity, which could play an important role in the pathogenesis of periodontitis.

• 한국식품영양과학회지
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• 제30권3호
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• pp.395-402
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• 2001

Bacillus subtilis 돌연변이주 중 ${\gamma}-GTP$활성이 높은 SM-2와 SM-10을 융합시켜 획득한 융합주 중 ${\gamma}-GTP$활성이 높은 융합주 FG-21의 배양적 특성을 조사하였다. 융합주 FG-21에 의한 ${\gamma}-GTP$의 생산은 1% glycerol, 1% peptone, 0.1% citric acid, 5 mM $K_2HPO_4$, 1 mM $FeCl_3$, 1 mM $MgCl_2$, 1 mM $NH_4Cl$, pH 7.0의 배지에 의해 $37^{\circ}C$에서 36시간 배양했을 때 621 U/mL으로 최대한 활성을 보였다. 융합주 FG-21이 생산한 biopolymer A가 단백질함량이 38.4%이고 B. subtilis K-1이 생산하는 biopolymer B의 단백질함량은 19.3%로 융합주 FG-21이 생산하는 Biopolymer A보다 함량이 낮았다. 융합주 FG-21의 biopolymer가 모균주의 biopolymer B보다 단백질함량이 높은 것은 상대적으로 높은 ${\gamma}-GTP$활성이 높아서 생성된 PGA가 levan보다 함량이 많기 때문인 것으로 사료된다. 총당함량은 biopolymer A가 58.5%, biopolymer B가 76.5%로 나타났다. 융합주 FG-21과 모균주가 생산하는 biopolymer의 단백질함량과 총당함량비는 융합주 FG-21이 생성한 biopolymer는 38 : 59. 모균주가 생산한 biopolymer B는 19 : 78의 비율이었고 HPLC 분석에 의한 biopolymer A와 B의 fructose함량은 각각 537.7 mg/g biopolymer, 764.4 mg/g biopolymer으로 나타났다. Biopolymer A와 B의 glutamic acid함량은 각각 163.7 mg/g, 94.3 mg/g이었다. Biopolymer A와 B의 fructose와 glutamic acid의 함량비는 각각 78 : 22, 89 : 11의 비로 함유되어 있었다. 따라서 융합주에 의해 생산된 biopolymer는 모균주보다 구성상태가 변화된 biopolymer를 생산한 것으로 판단되어 fusion과 같은 균주개량을 통하여 물질의 구성적, 물질적 변화된 biopolymer를 생산할 수 있을 것이라 사료된다.

• 한국임상수의학회지
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• 제7권2호
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• pp.471-487
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• 1990

Present experiment was performed in order to establish the optimum conditions for quantitation of ${\gamma}$-GTP and AGS activities in rat urine and investigate the applicability of the these enzymes in experimental assessment of nephrotoxicity in rats. The results obtained were as follows. 1. The optimal pH of Tris-BCI buffer containing glycylglycine for determination of urinary ${\gamma}$-GTP activity was 7.6(37$^{\circ}C$). 2. The Michaelis constant of urinary ${\gamma}$-GTP ranged from 1.1 to 1.2 mmol/$\ell$. 3. The optimal pH of citrate buffer for determination of urinary AGS activity was 3.6(37$^{\circ}C$). 4. The Michaelis constant of urinary AGS ranged from 0.8 to 0.9mmo1/$\ell$. 5. Coefficient of variance for within-run imprecision of urinary ${\gamma}$-GTP ranged from 3.8 to 6.4％ and that of urinary AGS ranged from 2.5 to 4.1％. 6. There was no significant difference between gel-filtered samples and crude samples in the mean activity of urinary ${\gamma}$-GTP and the intra-individual differences by gel-filtration were either increased or decreased. Mean values of ${\gamma}$ -GTP activities in gel-filtered samples and crude samples were 1570 and 1590 U/$\ell$, repectively. 7. The mean activity of urinary AGS increased significantly after gel-filtration and all the individual urines revealed higher activities after gel-filtration. 8. ${\gamma}$-GTP and AGS activities were linear to 135 and 7U/$\ell$, respectively. 9. Urinary ${\gamma}$-GTP and AGS excretion before administration of potassium dichromate were 22.1 ${\pm}$ 11.2 and 0.5${\pm}$0.2 U/24hrsㆍkg body weight respectively and increased significantly to 102.3${\pm}$44.5 and 5.8${\pm}$3.30/24hrsㆍkg body weight respectively within 24 hours after administration. 10. BUN increased continuously from 24 hours following exposure to potassium dichromate in all 10 rats. From these findings it is concluded that the urinary ${\gamma}$-GTP and AGS excretions are early and sensitive indicators for nephrotoxicity assessment in rat.