• 생명과학회지
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• 제8권5호
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• pp.497-503
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• 1998

GTase와 CDase를 함께 분비$\cdot$생산하는 B. stearother-mophilus KJl6 균주의 CDase를 ammonium sulfate 침전, DBAE-cellulose, Sephadex G-100 column chromatogra-phy, 및 FPLC로 수율 7%, 비활성 12.4 units/mg, 정제도 87.6배로 정제된 CDase를 얻었으며 SDS-PAGE 상 단일 band를 확인하였다. 정제된 CDase의 분자량은 약 68,000 dalton 이었고 활성 최적 pH와 온도는 6.0와 55$^{\circ}C$였다. pH 안정성은 5.5~8.5의 범위에서 비교적 안정하였으며, 온도 안정성은 5$0^{\circ}C$에서 2시간까지는 안정하였고, 7$0^{\circ}C$에서 1시간 전처리하여도 80% 이상의 잔존활성을 나타내었다. 효소 활성은 $Cu^{+2}$와 $Hg^{+2}$와 같은 금속이온과 p-chlorome-rcuribenzoate, N-bromosuccinimide, mercaptoethanol, dithiothreitol에 의해서 효소활성이 강하게 저해되었다. 기질에 대한 반응 특이성은 $\gamma$ -CD를 가장 잘 분해하였으며, 그 외에 soluble starch나 amylose, amylopectin 등의 기질도 잘 분해하나 이들의 분해속도는 $\gamma$-CD에 비해서는 늦었다. 이들 기질의 최종 분해산물은 maltose였으며, maltose는 거의 분해되지 않았다.

• 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.