• The Korean Journal of Zoology
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• v.18 no.1
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• pp.27-40
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• 1975

dbcAMP와 theophylline이 난자의 성숙을 억제하는 기작과 난자내 glycogen 함량과의 관계를 밝혀보기 위하여 실험한 결과는 다음과 같다. 1. 생쥐 여포난자의 PAS 양성물빌은 glycogen이며 핵의 성숙분열이 진행됨에 따라 glycogen의 함량은 감소한다. 2. dbcAMP나 theophylline에 의해 핵의 성숙이 억제된다 하더라도 난자내의 glycogenolysiss는 촉진된다. 이에 반해 핵분열이 일어나지 않은 난자는 배양이 진행되더라도 glycogen을 그대로 유지하고 있다. 일단 dbcAMP나 theophylline에 의해 성숙이 억제되었던 난자가 성숙과정에 들어가려면 다시 glyconeogenesis가 일어나 세포질내의 glycogen의 양이 회복하며 이때의 glycogen은 핵성숙과 더불어 소모된다. 3. Glycogen의 회복은 배양액내의 glucose 유무에 관계없이 이루어지며 따라서 이는 난자내 glucose 혹은 다른 전구물질에 의해 이루어지리라고 추측된다. 4. 결국 dbcAMP나 theophylline은 난자내 cAMP의 양을 증가시켜 glycogen의 소모를 일으키는 것으로 생각되며, glycogenolysis와 난자의 핵 성숙과정이 별개로 진행되기는 하지만 성숙의 요건은 일정량 이상의 glycogen이 함유되어 있어야 한다는 것을 알게되었다.

• The Korean Journal of Zoology
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• v.19 no.1
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• pp.1-6
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• 1976

The glycogen content of the oocytes at the various stages of meiotic division induced during culture was determined by a microspectrophotometer. The PAS intensity decreased gradually as the meiotic resumption progressed. The amount of glycongen was also decreased in the degenerated ova. Is is concluded that the glycogen consumption in necessary for the meiotic resumption and that the glycogen loss while the germinal vesicle is intact seems to lead degeneration. These results suggest that the endogenous glycogen is important to support meiosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1173-1176
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• 1998

Glycogen synthetase[EC 2.4.1.21] in E. coli B was isolated and purified by sonication, ultracentri fugation, DEAE cellulose chromatography and gel chromatography. In the case of using glycogen or maltotriose as a primer in the enzyme reaction, 64% and 23.7% of labelled ADP glucose were incorporated into primer, respectively. 8.1% of labelled ADP glucose was polymerized into glycogen in enzymatic reaction without a primer.

• BMB Reports
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• v.35 no.3
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• pp.283-290
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• 2002

The glycogen-associated protein phosphatase (PP1G/$R_{GL}$) may play a central role in the hormonal control of glycogen metabolism in the skeletal muscle. Here, we investigated the in vivo epinephrine effect of glycogen metabolism in the skeletal muscle of the wild-type and $R_{GL}$ knockout mice. The administration of epinephrine increased blood glucose levels from 200±20 to 325±20 mg/dl in both wild-type and knockout mice. Epinephrine decreased the glycogen synthase -/+ G6P ratio from 0.24±0.04 to 0.10±0.02 in the wild-type, and from 0.17±0.02 to 0.06±0.01 in the knockout mice. Conversely, the glycogen phosphorylase activity ratio increased from 0.21±0.04 to 0.65±0.07 and from 0.30±0.04 to 0.81±0.06 in the epinephrine trated wild-type and knockout mice respectively. The glycogen content of the knockout mice was substantially lower (27%) than that of both wild-type mice; and epinephrine decreased glycogen content in the wild-type and knockout mice. Also, in Western blot analysis there was no compensation of the other glycogen targeting components PTG/R5 and R6 in the knockout mice compared with the wild-type. Therefore, $R_{GL}$ is not required for the epinephrine stimulation of glycogen metabolism, and rather another phosphatase and/or regulatory subunit appears to be involved.

• Journal of Microbiology
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• v.39 no.1
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• pp.24-30
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• 2001

In addition to effecting the catalysis of sugar uptake, the bacterial phosphoenolpyruvate::sugar phosphotransferase system regulates a variety of physiological processes. In a previous paper [Seok et al.,(1997) J. Biol. Chem. 272, 26511-26521], we reported the interaction with and allosteric regulation of Esiherichia coli glycogen phosphorylase activity by the histidine-containing phosphocarrier protein HPr in vitro. Here, we show that the specific interaction between HPr and glycogen phosphorylase occurs in vivo. To address the physiological role of the HPr-glycogen phosphorylase complex, intracellular glycogen levels were measured in E. coli strains transformed with various plasmids. While glycogen accumulated during the transition between exponential and stationary growth phases in wildtype cells, it did not accumulate in cells overproducing HPr or its inactive mutant regardless of the growth stage. From these results, we conclude that HPr mediates crosstalk between sugar uptake through the phosphoenolpyruvate:sugar phosphotransferase system and glycogen breakdown. The evolutionary significance of the HPr-glycogen phosphorylase complex is suggested.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.29-39
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• 2018

Vibrio vulnificus needs various responsive mechanisms to survive and transmit successfully in alternative niches of human and marine environments, and to ensure the acquisition of steady energy supply to facilitate such unique life style. The bacterium had genetic constitution very different from that of Escherichia coli regarding metabolism of glycogen, a major energy reserve. V. vulnificus accumulated more glycogen than other bacteria and at various levels according to culture medium and carbon source supplied in excess. Glycogen was accumulated to the highest level in Luria-Bertani (3.08 mg/mg protein) and heart infusion (4.30 mg/mg protein) complex media supplemented with 1% (w/v) maltodextrin at 3 h into the stationary phase. Regarding effect of carbon source, more glycogen was accumulated when maltodextrin (2.34 mg/mg protein) was added than when glucose or maltose (0.78.1-14 mg/mg protein) was added as an excessive carbon source to M9 minimal medium, suggesting that maltodextrin metabolism might affect glycogen metabolism very closely. These results were supported by the analysis using the malP (encoding a maltodextrin phosphorylase) and malQ (encoding a 4-${\alpha}$-glucanotransferase) mutants, which accumulated much less glycogen than wild type when either glucose or maltodextrin was supplied as an excessive carbon source, but at different levels (3.1-80.3% of wild type glycogen). Therefore, multiple pathways for glycogen metabolism were likely to function in V. vulnificus and that responding to maltodextrin might be more efficient in synthesizing glycogen. All of the glycogen samples from 3 V. vulnificus strains under various conditions showed a narrow side chain length distribution with short chains (G4-G6) as major ones. Not only the comparatively large accumulation volume but also the structure of glycogen in V. vulnificus, compared to other bacteria, may explain durability of the bacterium in external environment.

• Journal of Ginseng Research
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• v.18 no.2
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• pp.102-107
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• 1994

When at liver homogenates were incubated with 1mM $CCl_4$ for five min, glycogen level was decreased, while treatment with protein fraction $G_4$ increased the glycogen level. In addition $G_4$ inhibited the phosphorylation of 34 KD and 118 KD polypeptides induced by $CCl_4$. These protein were more strongly phosphorylated by $Ca^{2+}$/calmodulin-dependent kinase than by C-kinase. Since 34 KD polypeptide was solely phosphorylated by NaF (50mM), an inhibitor of both glycogen syntheses and phosphoprotein phosphates, it is inferred that 3 KD polypeptide is glycogen synthase-likd protein. Because glycogen synthesis is inhibited by phosphorylation of $Ca^{2+}$-dependent glycogen syntheses, it is suggested that $G_4$ increased liver glycogen level by inhibiting phosphorylation of 34 KD polypeptide which is thought to glycogen syntheses-like protein.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.521-529
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• 1996

In an effort to obtain basic data of carbohydrate metabolism during spermiogenesis of the sexually-matured Jindo dog, the glycogen distribution in the testis was investigated by light and transmission electron microscopy. Periodic acid thiocarbohydrazide silver proteinate physical development(PA-TCH-SP-PD) staining method provided better results in the detection of glycogen granules from Sertoli cells and germ cells than the periodic acid schiff(PAS) staining method did. Pre-treatment of the tissue sections with ${\alpha}$-amylase elicited a significant decrease in PA-TCH-SP-PD stained granules, which suggested that the stained granules were of glycogen origin. High concentration of the glycogen granules were observed in the Sertoli cells, especially in its column, sheet-like processes, club-like processes, and tubular processes. The glycogen granules were unevenly distributed in some Sertoli cell columns. These results strongly indicated that the Sertoli cells of Jindo dogs showed vigorous activity of carbohydrate metabolism.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.79-86
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• 1988

In the present study the effect of exercise on the conversion rate of ingested glucose to glycogen in the different types of hindlimb skeletal muscles in Sprague-Dawley male rats was studied. The amounts of synthetized glycogen from ingested glucose of fast-twitch white(WV), fast-twitch red(RV), mixed type of fast-twitch white and red(EDL), and slow-twitch(SOL) muscles were determined at 30 and 90 min. after ingestion of 25% glucose solution which contained $^{14}C$-glucose($2m{\ell}(1uCi)$/100gm B. W.)in control and exercise loaded rats. The result was summarized as follows : The about 55% at 30 min. and 70% at 90 min. after glucose ingestion were absorbed from gastrointestinal tract. This result shows no effects of exercise on absorption rate from gastrointestinal tract. The amount of synthetized glycogen of SOL from ingested glucose at 30 and 90 min. after glucose ingestion were highest, whether WV were lowest in hindlimb skeletal muscles in control and exercise loaded rats. In the exercise loaded rats, the amounts of synthetized glycogen of SOL, RV, and EDL at 90 min. after glucose ingestion was much higher than control rats, but not different in WV between exercise-loaded and control rats. At 30 min. after glucose ingestion, only SOL of exercise loaded rats was higher than control rats. In the control rat, the synthesis of glycogen was almost completed during initial 30 minutes. On the other hand, in the exercise loaded rat, except WV was opposite result of control rats, i. e., amounts of synthetized glycogen were major during late period. The amount of synthetized glycogen of liver at 30 and 90 min. after glucose ingestion in exercise loaded rats was higher than control rats. The rate of glycogen synthesis in control and exercise loaded rats were higher between 30-90 minute than initial 30 minute.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.194-200
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• 2018

Glycogen plays important roles in bacteria. Its structure and storage capability have received more attention recently because of the potential correlations with environmental durability and pathogenicity. However, the low level of intracellular glycogen makes extraction and structure characterization difficult, inhibiting functional studies. Bacteria grown in regular media such as lysogeny broth and tryptic soy broth do no accumulate large amounts of glycogen. Comparative analyses of bacterial media reported in literature for glycogen-related studies revealed that there was no consistency in the recipes reported. Escherichia coli $DH5{\alpha}$ is a convenient model organism for gene manipulation studies with respect to glycogen. Additionally, M9 minimal salts medium is widely used to improve glycogen accumulation, although its composition varies. In this study, we optimized the M9 medium by adjusting the concentrations of itrogen source, tryptone, carbon source, and glucose, in order to achieve a balance between the growth rate and glycogen accumulation. Our result showed that $1{\times}M9$ minimal salts medium containing 0.4% tryptone and 0.8% glucose was a well-balanced nutrient source for enhancing the growth and glycogen storage in bacteria. This result will help future investigations related to bacterial physiology in terms of glycogen function.