• 한국동물학회:학술대회논문집
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• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
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• pp.229.2-229
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• 2001

No Abstract, See Full Text

• BMB Reports
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• 제42권8호
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• pp.523-528
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• 2009

Phosphomannose isomerase (PMI) catalyzes the interconversion of fructose-6-phosphate and mannose-6-phosphate in the extracellular polysaccharide (EPS) synthesis pathway. The gene encoding PMI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli. The pmi gene is 1,410 nucleotides long and the deduced amino acid sequence shares high homology with other bifunctional proteins that possess both PMI and GDP-mannose pyrophosphorylase (GMP) activities. The sequence analysis of PMI revealed two domains with three conserved motifs: a GMP domain at the N-terminus and a PMI domain at the C-terminus. Enzyme assays using the PMI protein confirmed its bifunctional activity. Both activities required divalent metal ions such as $Co^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $Ni^{2+}$ or $Zn^{2+}$. Of these ions, $Co^{2+}$ was found to be the most effective activator of PMI. GDP-D-mannose was found to inhibit the PMI activity, suggesting feedback regulation of this pathway.

• Journal of Plant Biotechnology
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• 제49권1호
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• pp.39-45
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• 2022

Conserved domains are defined as recurring units in molecular evolution and are commonly used to interpret the molecular function and biochemical structure of proteins. Herein, the ADP-glucose pyrophosphorylase (AGPase) amino acid sequences of three species of the Ipomoea genus [Ipomoea trifida, I. triloba, and I. batatas (L.) Lam. (sweetpotato)] were identified to investigate their physicochemical and biochemical characteristics. The molecular weight, isoelectric point, instability index, and grand average of hyropathy markedly differed among the three species. The aliphatic index values of sweetpotato AGPase proteins were higher in the small subunit than in the large subunit. The AGPase proteins from sweetpotato were found to contain an LbH_G1P_AT_C domain in the C-terminal region and various domains (NTP_transferase, ADP_Glucose_PP, or Glyco_tranf_GTA) in the N-terminal region. Conversely, most of its two relatives (I. trifida and I. triloba) were found to only contain the NTP_transferase domain in the N-terminal region. These findings suggested that these conserved domains were species-specific and related to the subunit types of AGPase proteins. The study may enable research on the AGPase-related specific characteristics of sweetpotatoes that do not exist in the other two species, such as starch metabolism and tuberization mechanism.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 추계학술발표회 요지
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• pp.212-213
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• 2005

• 한국식물학회:학술대회논문집
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• 한국식물학회 1998년도 The 12th Symposium on Plant Biotechnology Vol.12
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• pp.71-78
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• 1998

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2006년도 한국육종학회 공동심포지엄 및 학술대회
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• pp.36.1-36.1
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• 2006

• KSBB Journal
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• 제23권6호
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• pp.474-478
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• 2008

효율적인 UDP-glucose regeneration system을 구축하기 위해서 재순환 시스템에 관여하는 4가지 효소 (UDP-glucose pyrophosphorylase, UDP-Kinase gene, UDP-galactose 4-epimerase, and $\beta$-1, 4-galactasyltrasnsferase)들을 E. coli AD202에서 발현 시켜 Disaccharide 합성 정도를 보았다. Disaccharide는 0.5 mM IPTG 농도에서 가장 높은 농도를 나타내었다. 대조구와 비교한 결과 LacNAc 농도는 1.34 mM로 10배 정도 정가하였고, lactose 농도는 0.39 mM로 대조구보다 2.6배 증가하였다. 총 disaccharide 농도는 1.73 mM 이며, 대조구 보다 6.5배 높은 생산성을 보였다. 본 논문은 결과는 metabolic flux regeneration으로 disaccharides 합성을 증가시킬 수 있다는 것을 보여주었다.

• Journal of Plant Biotechnology
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• 제34권4호
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• pp.277-283
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• 2007

고구마 유래 ibAGP1, ibAGP2 유전자가 antisense 방향으로 각각 도입된 벡터를 섞어서 particle bombardment 방법으로 고구마 배발생 캘러스에 형질전환을 수행하였다. 선발배지에서 형성된 배발생 캘러스로부터 체세포 배발생 과정을 거쳐 식물체로 재분화된 개체에서 PCR과 Southern 분석으로 고구마의 염색체 게놈에 ibAGP1, ibAGP2 유전자가 도입되었음을 확인하였고, western blot을 통해 형질전환체의 AGPase small subunit 효소 생산이 전반적으로 대조구에 비해 감소하였다. 또한, 형질전환체의 잎과 괴근 절편체의 전분염색 결과에서도 대조구에 비해 부분적으로 전분염색이 이루어짐을 알 수 있었다. 특히, ibAGP1, ibAGP2 유전자가 동시에 들어 있는 식물체 잎에서는 ibAGP1만 들어있는 것에 비해 전분합성이 더욱 감소됨을 확인하였다. 고구마의 경우 감자를 비롯한 다른 식물들과는 달리 외형적인 생장자체를 심하게 저해하였으며 괴근이 형성되지 않아 ibAGP1, 2의 발현 여부가 식물체의 생장에 절대적인 영향을 미침을 시사한다.

• Parasites, Hosts and Diseases
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• 제50권4호
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• pp.361-364
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• 2012

The mature cyst of Acanthamoeba is highly resistant to various antibiotics and therapeutic agents. Cyst wall of Acanthamoeba are composed of cellulose, acid-resistant proteins, lipids, and unidentified materials. Because cellulose is one of the primary components of the inner cyst wall, cellulose synthesis is essential to the process of cyst formation in Acanthamoeba. In this study, we hypothesized the key and short-step process in synthesis of cellulose from glycogen in encysting Acanthamoeba castellanii, and confirmed it by comparing the expression pattern of enzymes involving glycogenolysis and cellulose synthesis. The genes of 3 enzymes, glycogen phosphorylase, UDP-glucose pyrophosphorylase, and cellulose synthase, which are involved in the cellulose synthesis, were expressed high at the 1st and 2nd day of encystation. However, the phosphoglucomutase that facilitates the interconversion of glucose 1-phosphate and glucose 6-phosphate expressed low during encystation. This report identified the short-cut pathway of cellulose synthesis required for construction of the cyst wall during the encystation process in Acanthamoeba. This study provides important information to understand cyst wall formation in encysting Acanthamoeba.

• Journal of Plant Biotechnology
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• 제37권2호
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• pp.205-211
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• 2010

Yield productivity of staple crops must be increased at least 50% by 2050, in order to feed the world population which is expected to reach 90 billions. Photosynthetic carbon assimilation and carbohydrate metabolism leading to the production of starch would be the final frontier to quest for new sources of technology enabling such a drastic increase of crop productivity. In this review, attempts to genetically engineer plant photosynthetic carbon reduction cycle and metabolic pathways to increase starch production are introduced.