• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.792-799
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• 2007

A gene encoding a putative glycogen-debranching enzyme in Sulfolobus shibatae(abbreviated as SSGDE) was cloned and expressed in Escherichia coli. The recombinant enzyme was purified to homogeneity by heat treatment and Ni-NTA affinity chromatography. The recombinant SSGDE was extremely thermostable, with an optimal temperature at $85^{\circ}C$. The enzyme had an optimum pH of 5.5 and was highly stable from pH 4.5 to 6.5. The substrate specificity of SSGDE suggested that it possesses characteristics of both amylo-1,6-glucosidase and $\alpha$-1,4-glucanotransferase. SSGDE clearly hydrolyzed pullulan to maltotriose, and $6-O-\alpha-maltosyl-\beta-cyclodextrin(G2-\beta-CD)$ to maltose and $\beta$-cyclodextrin. At the same time, SSGDE transferred maltooligosyl residues to the maltooligosaccharides employed, and maltosyl residues to $G2-\beta-CD$. The enzyme preferentially hydrolyzed amylopectin, followed in a decreasing order by glycogen, pullulan, and amylose. Therefore, the present results suggest that the glycogen-debranching enzyme from S. shibatae may have industrial application for the efficient debranching and modification of starch to dextrins at a high temperature.

• Food Science and Biotechnology
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• 제18권2호
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• pp.570-573
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• 2009

The debranching enzyme of Nostoc punctiforme (NPDE) is a novel enzyme that catalyzes the hydrolysis of $\alpha$-1,6-glycosidic linkages in starch, followed by the sequential hydrolysis of $\alpha$-1,4-glycosidic linkages. The debranching activity of NPDE is highly specific for branched chains with a degree of polymerization (DP)>8. Moreover, the rate of hydrolysis of $\alpha$-1,4-linkages by NPDE is greatly enhanced for maltooligosaccharides (MOs) with a DP>8. An analysis of reaction mixtures containing various starches revealed the accumulation of maltooctaose (G8) with glucose and maltose. Based on the novel enzymatic properties of NPDE, an MO mixture containing more than 60% G8 with yield of 18 g G8 for 100 g starch was prepared by the reaction of NPDE with soluble starch, followed by ethanol precipitation and gel permeation chromatography (GPC). The yield of the G8-rich mixture was significantly improved by the addition of isoamylase. In summary, a 4-step process for the production of a G8-rich mixture was developed involving the enzymatic hydrolysis of starch by NPDE.

• 대한유전성대사질환학회지
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• 제6권1호
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• pp.15-23
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• 2006

Purpose: Glycogen storage disease type III (GSD-III), is a rare autosomal recessive disorder of glycogen metabolism. The affected enzyme is amylo-1,6-glucosidase, 4-alpha-glucanotransferase (AGL, glycogen debranching enzyme), which is responsible for the debranching of the glycogen molecule during catabolism. The disease has been demonstrated to show clinical and biochemical heterogeneity, reflecting the genotype-phenotype heterogeneity among different patients. In this study, we analyzed mutations of the AGL gene in three unrelated Korean GSD-III patients and discussed their clinical and laboratory implications. Methods: We studied three GSD-III patients and the clinical features were characterized. Sequence analysis of 35exons and part exon-intron boundaries of the AGLgene in patients were carried out by direct DNA sequencing method using genomic DNA isolated from patients' peripheral leukocytes. Results: The clinical features included hepatomegaly (in all patients), seizures (in patient 2), growth failure (in patients 1), hyperlipidemia (in patients 1 and 3), raised transaminases and creatinine kinase concentrations (in all patients) and mild EKG abnormalities (in patients 2). Liver transplantation was performed in patient 2due to progressive hepatic fibrosis. Administration of raw-corn-starch could maintain normoglycemia and improve the condition. DNA sequence analysis revealed mutations in 5 out of 6 alleles. Patient 1 was a compound heterozygote of c.1282 G>A (p.R428K) and c.1306delA (p.S603PfsX6), patient 2 with c.1510_1511insT (p.Y504LfsX10), and patient 3 with c.3416 T>C (p.L1139P) and c.l735+1 G>T (Y538_R578delfsX4) mutations. Except R428K mutation, 4 other mutations identified in3 patients were novel. Conclusion: GSD-III patients have variable phenotypic characteristics resembling GSD-Ia. The molecular defects in the AGL gene of Korean GSD-III patients were genetically heterogeneous.

• Journal of Genetic Medicine
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• 제4권1호
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• pp.72-79
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• 2007

목 적 : 제3형 당원병은 상염색체 열성으로 유전되는 드문 글리코겐 대사 질환이다. 글리코겐 debranching 효소는 두 가지 효소의 기능을 가지는데, amylo-1,6-glucosidase와 4-alpha-glucanotransferase가 그것이며, 제3형 당원병에서는 글리코겐 debranching 효소의 결핍으로 글리코겐의 불완전한 분해가 초래되며, 다양한 임상 및 생화학적 양상을 보이는 것으로 알려져 있다. 본 연구에서는 3명의 한국인 환자의 임상 및 생화학적 양상을 분석하고, AGL 유전자의 돌연변이 형태를 밝히고자 하였다. 방 법 : 서로 혈연 관계가 없는 3명의 한국인 제3형 당원병 환자를 대상으로, 생화학적, 조직학적, 방사선학적 특징을 포함한 임상 양상을 의무 기록을 통하여 조사하였다. 환자의 말초혈액에서 백혈구를 분리하여 추출한 genomic DNA를 사용하여 직접적 염기 서열 분석법으로 AGL 유전자의 35개 exon 및 exon과 intron의 경계 부분을 조사하여 돌연변이를 조사하였다. 결 과 : 간비대, 경련, 저신장, 고지혈증, 간효소 수치의 증가, creatine kinase 수치의 증가, 경도의 심근증 등 다양한 임상 양상이 관찰되었고, 한 명의 환자는 진행성 간섬유화로 인하여 간이식 수술을 시행 받았다. 생옥수수 전분가루의 복용은 모든 환자에서 정상 혈당을 유지시키고, 생화학적 검사 소견을 개선시키며 정상적인 성장 속도를 보이게 하였다. AGL 유전자 분석 결과 6개의 대립유전자 중 5개에서 돌연변이를 확인할 수 있었으며, 이중에 p.R428K를 제외한 4개의 돌연변이는 이제까지 보고된 적이 없는 새로운 돌연변이(c.1306delA, c.1510-1511insT, c.3416 T>C, c.1735+1 G>T)였다. 결 론 : 제3형 당원병은 임상 증상 및 중등도가 다양한 질환으로, 제1형 당원병의 증상과 유사하여 초기에 감별이 쉽지 않으며, 한국인 환자에서의 AGL 유전자의 돌연변이 양상도 매우 이질적이다.

• Animal Bioscience
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• 제35권11호
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• pp.1733-1743
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• 2022

Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet. Methods: In vitro experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. In vivo experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme. Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed bran-containing diet. Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet.

• 대한유전성대사질환학회지
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• 제12권2호
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• pp.108-112
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• 2012

제 3형 당원병 (Glycogen Storage disease, Type III: OMIM #232400)은 상염색체 열성 유전을 하는 매우 드문 유전 질환으로, 1p21 염색체에 존재하는 AGL 유전자 (OMIM *610860)로부터 전사되는 글리코겐을 분해하는 효소인 가지제거효소(amylo-1,6 Glucosidase; EC 3.2.1.33 and 1,4-${\alpha}$-D-glucan 4-${\alpha}$-D-glycosyltransferase; EC 2.4.1.25)의 결함으로 인해 유발되는 질환이다. 제 3형 당원병의 환자들은 분해되지 못한 글리코겐이 조직에 축적되면서 증상이 발생하는데, 효소가 분포하던 조직에 따라 그 증상은 다양하게 나타난다. 제 3a형 당원병에서 간비대, 저신장, 그리고 저혈당증 증상은 아동기에 주로 나타나나 나이가 들면서 증상이 호전되어 사춘기를 전후하여 정상이 되는 경우가 많으며, 심근병증 및 근무력감, 운동발달지연 등의 근질환 증상은 영아기나 아동기에는 뚜렷하지 않지만 나이가 들면서 심해져 30-40대 이후 성인기에 나타나는 경우가 많다. 저자들은 간비종대, 심근 약화 증상, 근무력증 등의 전형적인 제 3a형 당원병의 임상증상 및 생화학적 특성이 관찰된 25세 여환에게서, AGL 유전자의 분석을 통해 제 3a형 당원병을 확진하였기에 이를 보고하는 바이다.

• Journal of Microbiology and Biotechnology
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• 제32권6호
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• pp.749-760
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• 2022

α-Galactosidase is a debranching enzyme widely used in the food, feed, paper, and pharmaceuticals industries and plays an important role in hemicellulose degradation. Here, T26, an aerobic bacterial strain with thermostable α-galactosidase activity, was isolated from laboratory-preserved lignocellulolytic microbial consortium TMC7, and identified as Parageobacillus thermoglucosidasius. The α-galactosidase, called T26GAL and derived from the T26 culture supernatant, exhibited a maximum enzyme activity of 0.4976 IU/ml when cultured at 60℃ and 180 rpm for 2 days. Bioinformatics analysis revealed that the α-galactosidase T26GAL belongs to the GH36 family. Subsequently, the pET-26 vector was used for the heterologous expression of the T26 α-galactosidase gene in Escherichia coli BL21 (DE3). The optimum pH for α-galactosidase T26GAL was determined to be 8.0, while the optimum temperature was 60℃. In addition, T26GAL demonstrated a remarkable thermostability with more than 93% enzyme activity, even at a high temperature of 90℃. Furthermore, Ca²⁺ and Mg²⁺ promoted the activity of T26GAL while Zn²⁺ and Cu²⁺ inhibited it. The substrate specificity studies revealed that T26GAL efficiently degraded raffinose, stachyose, and guar gum, but not locust bean gum. This study thus facilitated the discovery of an effective heat-resistant α-galactosidase with potent industrial application. Meanwhile, as part of our research on lignocellulose degradation by a microbial consortium, the present work provides an important basis for encouraging further investigation into this enzyme complex.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권6호
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• pp.451-455
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• 2022

Glycogen storage disease (GSD) is a group of inherited disorders, which result in the deficiency of enzymes involved in glycogen metabolism, leading to an accumulation of glycogen in various organs. Deficiency of amylo-1-6-glicosidase (debranching enzyme) causes glycogen storage disease type III (GSD III). The main problems that anesthesiologists face in patients with GSD III include hypoglycemia, muscle weakness, delayed awakening due to abnormal liver function, possible difficulty in airway, and cardiomyopathy. In the face of these difficulties, airway preparation and appropriate glucose monitoring and support during the fasting period are important. The doses of the drugs to be used should be calculated considering the increased volume of distribution and decreased metabolic activity of the liver. We present the case of a child with GSD IIIa who underwent dental prosedation under general anesthesia. She was also being prepared for liver transplantation. This case was additionally complicated by the patient's serious allergic reaction to eggs and milk.

• 한국식품영양과학회지
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• 제25권2호
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• pp.255-260
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• 1996

증편반죽의 발효에 따른 해면상의 조직(망상구조)형성능의 mechanism을 조사하기 위하여 반죽의 구성성분의 경시적 물성 및 효소(diastase 및 protease) 활성의 변화, 구성 전분 분획의 glucose chain length 변화 및 1% SDS에 의해서 용출되는 단백질 분획의 변화에 대해서 검토하였다. 발효가 진행됨에 따라 증편반죽의 pH는 감소한 반면 점성 및 부피는 발효경과 10시간가지 증가하다가 그 이후로는 약간 감소하는 경향을 보였다. 발효의 진행과 더불어 diastase의 활성은 증가하였으며, 쌀전분 분획 중 amylose의 함량은 약간 감소하였다. 그리고 전분분자의 $\alpha-1,6-glucoside$ 결합을 isoamylase(debranching enzyme)로 가수분해시킨 후 Sephadex G-75를 이용한 chromatogram 분석에 의하면 쌀가루 전분 분획과 증편반죽 전분 분획의 glucose chain length 분포는 거의 유사하지만 발효가 진행됨에 따라 중합도가 낮은 부분이 우선적으로 diastase의 작용을 받은 것이라고 생각되어진다. 한편, 발효가 진행된에 따라 protease의 활성은 증가하고 있었음에도 불구하고 증편반죽의 당에 의한 단백질 분획의 고분자화가 Suprose CL-12 column chromatogram 상에서 관찰되었는데, 이것은 아마도 발효과정 중 증편반죽에 공존하는 미생물들의 발효산물인 당질(gum질)을 매개로 한 단백질 분자의 회합에 의한 결과라고 생각되어진다. 따라서 이러한 결과를 미루어 볼 때 증편반죽의 망상구조 형성능은 발효과정 중 일어나는 당과 단백질간의 상호작용에 의한 결과라 생각되어진다.

• 한국식품과학회지
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• 제33권1호
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• pp.50-54
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• 2001

8품종 변이체 쌀 전분의 청가에 의한 아밀로오스 함량의 차이는 남풍벼>화청벼>분질미>남풍 CB243>화청 du-1>남풍 EM90>화청찰벼>shr.의 순이었다. 아밀로펙틴의 미세구조는 효소처리에 의해서 debranching시킨 전분의 glucose chain length분포 비교에 의해서 수행되었고, 품종별로 미세구조상에 차이가 있었다. 아밀로오스 함량이 낮을수록 씹힘성이 좋은 쌀빵의 제조가 가능하였으며, 아밀로펙틴 분획에 짧은 쇄장을 많이 함유하는 품종일수록 질감 및 기호도가 높은 쌀빵의 제조가 가능하였다.