• 약학회지
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• 제43권6호
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• pp.818-826
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• 1999

Antidiabetic activity and mechanism of Sangbackpitang (SBPT) was examined in db/db mice, which is a spontaneously hyperglycemic, hyperinsulinemic and obese animal model. SBPT and acarbose were administered orally for 4 weeks. Fasting and non-fasting serum glucose, glycated hemoglobin and triglyceride were all reduced when compared between db/db control group and SBPT treated group. At 12th week after birth, SBPT increased an insulin secretion although statistic significance was not seen. Total activities of sucrase, maltase and lactase in SBPT treated group were all decreased when compared to db/db control. On the other hand, sucrase and maltase activities in acarbose treated groups were increased. Effect of SBPT on mRNA expression of glucose transporter(GLUT-4) was also examined. Quantitation of glucose transporter was performed by RT-PCR and in vitro transcription with co-amplification of rat-action gene as an internal standard. Muscular GLUT-4 mRNA expression in SBPT treated group was increased significantly. These results may suggest that SBPT lowered blood glucose ascribing to inhibition of glycosidase-catalyzed reaction and upregulation of muscular GLUT-4 mRNA expression.

• Food Science and Biotechnology
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• 제15권6호
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• pp.851-855
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• 2006

Acarviosine-glucose (AcvGlc) is an ${\alpha}$-glucosidase inhibitor and has similar inhibitory activity to acarbose in vitro. We synthesized AcvGlc by treating acarbose with Bacillus stearothermophilus maltogenic amylase and fed C57BL/6J and db/db mice with diets containing purified AcvGlc and acarbose for 1 week. AcvGlc (50 and 100 mg/100 g diet) significantly reduced plasma glucose and triglyceride levels in db/db mice by 42 and 51 %, respectively (p<0.0001). The hypoglycemic and hypotriglyceridemic effects of AcvGlc were slightly, but significantly, greater than those seen with acarbose treatment (p<0.0001) in C57BL/6J mice. In an oral glucose tolerance test, glucose tolerance was significantly improved at all time points (p<0.01). The expression of two novel glucose transporters (GLUTs), GLUT10 and GLUT12, were examined by Western blot analysis. GLUT10 was markedly increased in the db/db livers. After AcvGlc treatment, the expression of hepatic GLUT10 was decreased whereas intestinal GLUT12 was significantly increased in both strains of mice. Our results show that AcvGlc improves plasma lipid and glucose metabolism slightly more than acarbose. Regulation of hepatic GLUT10 and intestinal GLUT12 may be important in controlling blood glucose levels.

• Biomolecules & Therapeutics
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• 제7권4호
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• pp.335-341
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• 1999

Antidiabetic activity and mechanism of Supungsungihyan(SPSGH) were examined in db/db mice, which is a spontaneously hyperglycemic, hyperinsulinemic and obese animal model. SPSGH and acarbose were administered orally for 4 weeks. Fasting and non-fasting serum glucose, glycated hemoglobin and trig-lyceride of SPSGH treated group were all reduced when compared with those of db/db control group. At 12th week after birth, SPSGH increased an insulin secretion although statistic significance was not seen. Total activities of sucrose, maltase and lactase in SPSGH treated group were not significantly different from those in db/db control. On the other hand, sucrase and maltase activities in acarbose treated groups were increased. Effect of SPSGH on mRNA expression of glucose transporter(GLUT-4) was also examined by RT-PCR and in vitro transcription with co-amplification of rat $\beta$-actin gene as an internal standard. Muscular GLUT-4 mRNA expression in SPSGH treated group was increased significantly. These results may suggest that SPSGH lowered blood glucose ascribing to upregulation of muscular GLUT-4 mRNA expression.

• BMB Reports
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• 제30권4호
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• pp.240-245
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• 1997

Interactions between ganglioside $G_{M3}$ and glucose transporter, GLUT1 were studied by measuring the effect of $G_{M3}$ on steady-state and time-resolved fluorescence of purified GLUT1 in synthetic lipids and on the 3-O-methylglucose uptake by human erythrocytes. The intrinsic tryptophan fluorescence showed a GLUT 1 emission maximum of 335 nm, and increased in the presence of $G_{M3}$ by 12% without shifting the emission maximum, The fluorescence lifetimes of intrinsic tryptophan on GLUT1 consisted of a long component of 7.8 ns and a short component of 2,3 ns and $G_{M3}$ increased both lifetime components. Lifetime components were quenched by acrylamide and KI. Acrylarnide-mduced quenching of long-lifetime components was partly recovered by $G_{M3}$ However. KI-induccd quenching of short- and long-lifetime components was not rescued by $G_{M3}$. The anisotropy of 1.6-diphenyl-1.3.5-hexatriene (DPH)-probed dimyristoylphosphatidylcholine (DMPC) model membrane was also increased with $G_{M3}$ incorporation, The transport rate of 3-O-methylglucose increased by 20% with $G_{M3}$ incorporation on the erythrocytes, Therefore, $G_{M3}$ altered the environment of lipid membrane and induced the conformational change of GLUT1.

• Reproductive and Developmental Biology
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• 제39권4호
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• pp.97-104
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• 2015

Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1944-1949
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• 2020

Mutant sugar transporter ScGAL2-N376F was overexpressed in Kluyveromyces marxianus for efficient utilization of xylose, which is one of the main components of cellulosic biomass. K. marxianus ScGal2_N376F, the ScGAL2-N376F-overexpressing strain, exhibited 47.04 g/l of xylose consumption and 26.55 g/l of xylitol production, as compared to the parental strain (24.68 g/l and 7.03 g/l, respectively) when xylose was used as the sole carbon source. When a mixture of glucose and xylose was used as the carbon source, xylose consumption and xylitol production rates were improved by 195% and 360%, respectively, by K. marxianus ScGal2_N376F. Moreover, the glucose consumption rate was improved by 27% as compared to that in the parental strain. Overexpression of both wild-type ScGAL2 and mutant ScGAL2-N376F showed 48% and 52% enhanced sugar consumption and ethanol production rates, respectively, when a mixture of glucose and galactose was used as the carbon source, which is the main component of marine biomass. As shown in this study, ScGAL2-N376F overexpression can be applied for the efficient production of biofuels or biochemicals from cellulosic or marine biomass.

• 미생물학회지
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• 제47권4호
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• pp.281-288
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• 2011

스트레스 반응에 관여하는 Saccharomyces cerevisiae 전사인자인 Msn2/4의 $C_2H_2$ zinc finger 부위와 아미노산 서열 유사성을 보이는 Aspergillus nidulans MsnA의 하위 유전자 획득을 위하여 msnA 결손 돌연변이체 또는 과발현 균주에서 야생주와 비교하여 차별적으로 발현되는 유전자(Differentially Expressed Gene, DEG)들을 분리하였다. 선별된 DEG들은 염기서열 결정을 통해 해당 유전자들을 동정하였고 이들 중 DEG6는 단당류 수송자(monosaccharide transporter)로 예측된 mstB 유전자로 밝혀졌다. mstB의 발현은 MsnA 과발현에 의하여 증가되었으며 MsnA는 in vitro에서 mstB 프로모터 부위에 직접적으로 결합하였다. MstB는 12개의 막결합 부위를 가지며 A. niger의 고친화성 단당류 수송자(high-affinity monosaccharide transporter)인 MstA와 80%의 높은 아미노산 서열 동일성을 보였다. mstB 결손 돌연변이체의 표현형은 야생주와 유사하였으나 MstB가 과발현된 균주는 낮은 당 농도인 0.1% glucose 배지에서 유성생식 기관인 cleistothecia의 형성이 증가하였다. 이러한 결과는 단당류 수송자인 MstB가 유성분화 과정에서 요구되는 당의 수송에 관여하고 있음을 시사한다.

• 한국미생물·생명공학회지
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• 제38권1호
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• pp.7-12
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• 2010

S. cerevisias의 치명적인 약점인 xylose 또는 arabinose가 상당부분을 차지하는 hemicellulose 기수분해물인 오탄당 발효의 극히 낮은 효율은 유전자 변형 및 대사적 흐름을 조절하여 세포 내로의 오탄당 섭취 및 활용 증가를 위한 연구가 꾸준히 진행되고 있다. S. cerevisie에서 오탄당은 육탄당보다 1-2 배 낮은 친화력을 가지고 있어, 오탄당 운반은 이를 이용한 바이오에탄올 발효에 있어서 중요한 초기 조절 단계이다. 오탄당 이용가능 S. cereivsiae에서 오탄당 운반기의 발현 관련 소수의 연구가 보고되고는 있으나 아직까지 눈에 띠는 효율 증기눈 보교되지 않았다. 최근 보고된 S. cerevisiae에서 C. intermeda 유래의 glucose/xylose의 확산을 용이하게 하는 운반기와 공동수송기의 이종발현이 처음으로 활성화 되었음이 보고 되었다. 따라서 그러므로 높은 친화력의 xylose 운반기의 발현은 이미 xylose로 부터 바이오에탄올 발효공정은 최적화되어 있지만 여전히 몇 가지 제한 요소들을 가지고 있는 S. cerevisiae 균주들의 xylsoe 발효공정 효율 향상에 큰 기여를 할 수 있을 것으로 기대된다.

• 대한의생명과학회지
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• 제12권1호
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• pp.17-22
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• 2006

The baculovirus expression system is a powerful method for producing large amounts of the human erythrocyte-type glucose transport protein, heterologously. Characterization of the expressed protein is expected to show its ability to transport sugars directly. To achieve this, it is a prerequisite to know the properties of the endogenous sugar transport system in Spodoptera frugiperda Clone 21 (Sf21) cells, which are commonly employed as a host permissive cell line to support the baculovirus replication. The Sf21 cells can grow well on TC-100 medium that contains 0.1% D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transport system. However, unlike the human glucose transport protein that has a broad substrate and inhibitor specificity, very little is known about the nature of the endogenous sugar transport system in Sf21 cells. In order to characterize further the inhibitor recognition properties of the Sf21 cell transporter, the ability of phloretin, cytochalasin B and D-fructose to inhibit 2-deoxy-D-glucose (2dGlc) transport was examined by measuring inhibition constants $(K_i)$. The $K_i's$ for reversible inhibitors were determined from plots of uptake versus inhibitor concentration. The 2dGlc transport in the Sf21 cells was very potently inhibited by phloretin, the aglucone of phlorizin with a $K_i$ similar to the value of about $2{\mu}M$ reported for inhibition of glucose transport in human erythrocytes. However, the Sf21 cell transport system was found to differ from the human transport protein in being much less sensitive to inhibition by cytochalasin B (apparent $K_i$ approximately $10\;{\mu}M$). In contrast, It is reported that the inhibitor binds the human erythrocyte counterpart with a $K_d$ of approximately $0.12\;{\mu}M$. Interestingly, the Sf21 glucose transport system also appeared to have high affinity for D-fructose with a $K_i$ of approximately 5mM, contrasting the reported $K_m$ of the human erythrocyte transport protein for the ketose of 1.5M.

• 생약학회지
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• 제39권3호
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• pp.228-232
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• 2008

Antidiabetic effects of an aqueous and solvent extract prepared from the root, stem and fruit parts of Acanthopanax senticosus, were investigated in experimental Streptozotocin (STZ)-induced diabetic rats model. The n-butanol and water extracts of A. senticosus were orally administrated once a day for 6 days. The n-butanol extracts of fruit (FB) showed highest efficiency than other groups (water extracts of stem, root and fruit; butanol extracts of stem, root) on serum glucose values in the STZ-induced diabetic rats. We have studied gene expression of glucose transporter genes in C2C12 skeletal muscle cell line during differentiation treated by the n-butanol and water extracts of A. senticosus, SW, RW, FW, SB, RB and FB. The GLUT4 gene was high expressed by FB treatment. These findings suggest that FB of A. senticosus have GLUT4 gene expression activity for glucose homeostasis and may have beneficial effects on blood glucose lowering in the diabetic patients.