• Journal of Microbiology
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• v.45 no.4
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• pp.318-325
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• 2007

Glucose 6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) in Deinococcus radiophilus, an extraordinarily UV-resistant bacterium, was investigated to gain insight into its resistance as it was shown to be involved in a scavenging system of superoxide $(O_2^{-1})$ and peroxide $(O_2^{-2})$ generated by UV and oxidative stresses. D. radiophilus possesses two G6PDH isoforms: G6PDH-1 and G6PDH-2, both showing dual coenzyme specificity for NAD and NADP. Both enzymes were detected throughout the growth phase; however, the substantial increase in G6PDH-1 observed at stationary phase or as the results of external oxidative stress indicates that this enzyme is inducible under stressful environmental conditions. The G6PDH-1 and G6PDH-2 were purified 122- and 44-fold (using NADP as cofactor), respectively. The purified G6PDH-1 and G6PDH-2 had the specific activity of 2,890 and 1,033 U/mg protein (using NADP as cofactor) and 3,078 and 1,076 U/mg protein (using NAD as cofactor), respectively. The isoforms also evidenced distinct structures; G6PDH-1 was a tetramer of 35 kDa subunits, whereas G6PDH-2 was a dimer of 60kDa subunits. The pIs of G6PDH-1 and G6PDH-2 were 6.4 and 5.7, respectively. Both G6PDH-1 and G6PDH-2 were inhibited by both ATP and oleic acid, but G6PDH-1 was found to be more susceptible to oleic acid than G6PDH-2. The profound inhibition of both enzymes by ${\beta}-naphthoquinone-4-sulfonic$ acid suggests the involvement of lysine at their active sites. $Cu^{2+}$ was a potent inhibitor to G6PDH-2, but a lesser degree to G6PDH-1. Both G6PDH-1 and G6PDH-2 showed an optimum activity at pH 8.0 and $30^{\circ}C$.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.84-87
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• 2006

Batch binding experiments were performed to assess the recovery performance of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) bound to the unshielded and polymer (polyvinyl pyrrolidone. PVP)-shielded dye-ligand (Cibacron Blue 3GA) adsorbent. The adoption of a polymer-shielded, dye-ligand technique facilitated the elution efficiency of bound G3PDH. It was demonstrated that the recovery of G3PDH using polymer-shielded dye-ligand adsorption yielded higher elution efficiency, at 60.5% and a specific activity of 42.3 IU/mg, after a low ionic strength elution (0.15 M NaCl). The unshielded dye-ligand yielded lower elution efficiency. at 6.5% and a specific activity of 10.2 IU/mg.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.3
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• pp.301-307
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• 1995

소 체외수정란에 있어서 pentose phosphate pathway (PPP)를 연구하기 위해서, 한개의 체외수정란으로부터 glucose 6-phosphate dehydrogenase (G6PDH)의 활성을 효소증폭방법으로 측정하였다. Glucose 6-phosphate (G6P) 기질을 처리하지 않은 2, 4, 8세포기, 상실배 및 배반포기 수정란에서의 G6PDH 활성치는 각각 $25.5{\pm}3.3$, $27.8{\pm}3.4$, $40.9{\pm}6.2$, $34.9{\pm}3.6$ 및 $52.9{\pm}2.5{\times}10^{-8}mol/embryo/h$ 을 나타내었다. 즉, 8 세포기 이후 수정란들은 2 세포기나 4 세포기보다도 높은 효소활성치를 보여주었다 (P<0.01). 그리고 G6P 기질을 첨가한 2,4,8 세포기, 상실배기 및 배반포기 수정란의 G6PDH 활성치는 각각 $32.3{\pm}3.9$, $29.4{\pm}1.8$, $51.9{\pm}4.2$, $42.6{\pm}2.7$ 및 $52.9{\pm}2.5{\times}10^{-8}mol/embryo/h$ 로서 기질 무처리구와 마찬가지로 유의성이 인정되었다 (P<0.01). 전반적으로 수정란의 발달단계에 있어서 G6P 첨가한 수정란들에 G6PDH의 효소활성치가 기질을 처리하지 수정란들의 것보다도 높은 경향을 보였다. 한편, 소 체외수정란의 G6PDH 효소활성치와 발생능과의 관계를 알아보기 위하여, 4 세포기 수정란들을 효소활성치의 정량적 수준 (low, middle, high)에 따라 3 군으로 분류한 다음 $38.5^{\circ}C$, 5% $CO_2$에서 5일간 난구세포들과 공동배양을 실시하였다. 그 결과, G6PDH 효소활성치 차이에 따른 수정란들의 체외발달율에는 유의성이 인정되지 않았다. 본 실험의 결과를 종합하여 볼 때, 소 체외수정란에 있어서 PPP 대사는 8세포기 이후부터 활발히 이루어지고 있음을 알 수 있었다.

• YAKHAK HOEJI
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• v.27 no.2
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• pp.117-124
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• 1983

For development of $EMIT-T_{3}$ assay, the conjugation of 3, 5, 3'-triiodothyroformic acid NHS ester to G6PDH was attempted in various reaction conditions. Up to now, the best conjugation condition was the ratio of $T_{3}$-NHS:G6PDH=100 in 25% carbitol-Tris buffer at pH 9, $0^{\circ}C$ during overnight. The obtained $T_{3}$-G6PDH conjugates usually had 20% residual enzyme activity which was inhibited by 40-70% with various $anti-T_{3}$ antibodies. Utilizing the conjugate I and an antibody (S2633G), a useful standard curve for $T_{3}$ assay was obtained in the range of 0 to 5ng/ml with 499 EMIT units of separation.

• The Korean Journal of Mycology
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• v.42 no.2
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• pp.138-143
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• 2014

Several isolates were collected from apple, pepper, strawberry, cucumber and tomato having typical gray mold symptoms. All the isolates were identified as Botrytis cinerea by using morphological characteristics and PCR-RFLP method. It was difficult to analyze the phylogenetic relationship of these isolates by using ITS region, HSP60 and G3PDH because these genes were highly homologous in their nucleotide in inter-species of B. cinerea and intra-species of genus Botrytis. However, phylogenetic analysis using combined sequences (RPB2, HSP60 and G3PDH genes) clearly showed that all isolate of B. cinerea were different from Botrytis spp. Furthermore, it was also confirmed that strawberry isolate was distantly related to apple, pepper, cucumber and tomato isolates that were closely related to each other in nucleotide level.

• Journal of Korean Academy of Nursing
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• v.19 no.3
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• pp.299-306
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• 1989

In order to evaluate the effect of fish oil on lipid drogenase(G6PDH), malic enzyme(ME), glucose-6-phosphatase(G6Pase) activities were measured in liver and adipose tissue of rats fed 13 days supplemented fish oil at the level of 10% (W/W). Two other groups of rats were fed 10% soybean oil or lard to compare with the effect of fish oil. In all groups, activities of hepatic G6PDH and ME were depressed from the beginning of feeding. This effect was greatest (50%) in fish oil group. Hepatic G6Pase was highest in rats fed lard. When the level of fish oil was reduced to half, as total fat content was maintained at the level of 10% by complementary lard, lipogenic enzyme depressing effect of fish oil was as significant as shown in 10% fish oil diet. Hepatic G6PDH was depressed significantly(14%) in rats fed fish oil as low as 2％. On the other hand, changes in adipose tissue G6PDH and ME activities were small. Adipose tissue G6Page activity increased slightly in rats fed with increasing fish oil(above 0.5%). It is suggested that fish oil alter, more markedly than either soybean oil or lard, cellular lipid metabolism by reducing activities of hepatic lipogenic enzymes.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.284-288
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• 2005

Baker's yeast was disrupted in a 1.4-L stainless steel horizontal bead mill under a continuous recycle mode using 0.3 mm diameter zirconia beads as abrasive. A single pass in continuous mode bead mill operation liberates half of the maximally released protein. The maximum total protein release can only be achieved after passaging the cells 5 times through the disruption chamber. The degree of cell disruption was increased with the increase in feeding rate, but the total protein release was highest at the middle range of feeding rate (45 L/h). The total protein release was increased with an increase in biomass concentration from 10 to $50\%$(w/v). However, higher heat dissipation as a result of high viscosity of concentrated biomass led to the denaturation of labile protein such as glucose 6-phosphate dehydrogenase (G6PDH). As a result the highest specific activity of G6PDH was achieved at biomass concentration of $20\%$(ww/v). Generally, the degree of cell disruption and total protein released were increased with an increase in impeller tip speed, but the specific activity of G6PDH was decreased substantially at higher impeller tip speed (14 m/s). Both the degree of cell disruption and total protein release increased, as the bead loading increased from 75 to $85\% (v/v)$. Hence, in order to obtain a higher yield of labile protein such as G6PDH, the yeast cell should not be disrupted at biomass concentration and impeller tip speed higher than $20\%(w/v)$ and 10 m/s, respectively.

• Journal of Microbiology and Biotechnology
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• v.29 no.4
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• pp.577-586
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• 2019

The engineered Aspergillus oryzae has a high NADPH demand for xylose utilization and overproduction of target metabolites. Glucose-6-phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) is one of two key enzymes in the oxidative part of the pentose phosphate pathway, and is also the main enzyme involved in NADPH regeneration. The open reading frame and cDNA of the putative A. oryzae G6PDH (AoG6PDH) were obtained, followed by heterogeneous expression in Escherichia coli and purification as a his6-tagged protein. The purified protein was characterized to be in possession of G6PDH activity with a molecular mass of 118.0 kDa. The enzyme displayed maximal activity at pH 7.5 and the optimal temperature was $50^{\circ}C$. This enzyme also had a half-life of 33.3 min at $40^{\circ}C$. Kinetics assay showed that AoG6PDH was strictly dependent on $NADP^+$ ($K_m=6.3{\mu}M$, $k_{cat}=1000.0s^{-1}$, $k_{cat}/K_m=158.7s^{-1}{\cdot}{\mu}M^{-1}$) as cofactor. The $K_m$ and $k_{cat}/K_m$ values of glucose-6-phosphate were $109.7s^{-1}{\cdot}{\mu}M^{-1}$ and $9.1s^{-1}{\cdot}{\mu}M^{-1}$ respectively. Initial velocity and product inhibition analyses indicated the catalytic reaction followed a two-substrate, steady-state, ordered BiBi mechanism, where $NADP^+$ was the first substrate bound to the enzyme and NADPH was the second product released from the catalytic complex. The established kinetic model could be applied in further regulation of the pentose phosphate pathway and NADPH regeneration of A. oryzae to improve its xylose utilization and yields of valued metabolites.

• Toxicological Research
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• v.35 no.3
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• pp.249-255
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• 2019

Cadmium is a strong toxic heavy metal which presents in paints and liquid wastes and causes oxidative stress in fish. On the other hand, lead is widely used for different purposes, e.g. lead pipes, it targets vital organs such as liver and kidney causing biochemical alterations. The present study evaluates the effects of 60 days exposure to Cd and Pb either single or combined together in African catfish. Sixty-four fishes were divided into 3 groups and exposed to $CdCl_2$ (7.02 mg/L) or $PbCl_2$ (69.3 mg/L) or a combination of them along with control group. Activities of acid phosphatase (ACP), lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) were estimated. Moreover, gill, liver and kidney were assayed for activities of superoxide dismutase (SOD), catalase (CAT) and levels of glutathione (GSH) and malondialdehyde (MDA). Individual exposure showed that both Cd and Pb significantly decreased LDH activity and SOD activity in the kidney. Pb significantly increased G-6-PDH activity and decreased GSH level in the gill. CAT activity in liver and kidney elevated significantly on Cd exposure while lead caused a significant depletion in the liver and significant elevation in the kidney. Both Cd and Pb significantly increased MDA levels in liver and kidney while Pb increased its level in gills. The combined exposure resulted in normalization of LDH, G-6-PDH activity, and CAT activity in liver and kidney as well as GSH level in both tissues and MDA in gill and kidney. The combination increased SOD activity and MDA level in liver and decreased SOD activity in kidney and GSH level in gills. In conclusion, the antioxidant system of African catfish was adversely affected by prolonged exposure to Cd and Pb. The combined exposure caused less damage than individual exposure and returned most parameters to those of controls.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1703-1712
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• 2015

The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.