• Journal of Microbiology and Biotechnology
• /
• 제2권4호
• /
• pp.260-267
• /
• 1992

Pectate lyase from alkalitolerant Bacillus sp. YA-14 is an endo-type pectate lyase which acts randomly at the $\alpha$-1, 4-galacturonan linkage, and requires calcium or strontium ions for its activity. The enzyme is active on low methyl esterified pectin, but the activity toward a high methyl esterified substrate is reduced. The apparent Km's of the enzyme toward sodium polygalacturonic acid, polygalacturonic acid, and various pectins such as apple pectin, citrus pectin, and genu pectin are 0.826 mg/ml, 0.685 mg/ml, and 1.14 mg/ml, respectively. The enzyme activity is inhibited by SDS, urea, and sodium azide, but not by various reducing reagents, such as $\beta$-mercaptoethanol, Na-thiosulfate, Na-sulfate, cystein, and L-ascorbic acid. The enzyme is inactivated by N-bromosuccinimide, $I_2, H_2O_2$. PMSF, and iodoacetate. Judging from the results of their inhibition types, we speculate that tryptophan and serine residues are directly involved in enzyme activity, while tyrosine and methionine residues are indirectly involved in its activity.

• 한국식품영양학회지
• /
• 제10권2호
• /
• pp.180-185
• /
• 1997

찹쌀 20%, 엿기름 4%를 가하여 7시간 동안 당화시켜 제조한 식혜는 말통스 10.1%, 한계덱스트린 7.3%, 말토트링스 1.3%, 글루코오스 0.18%, 밥알 1.75%를 나타냈다. 알코올 침전, Biogel P-2의 겔 크로마토그래피로 식혜의 한계덱스트린을 정제하여 1H-NMR 분석한 결과 한계덱스트린은 $\alpha$-1,4-글루코시드 결합과 $\alpha$-1,6-글루코시드 결합이 5:1로 이루어졌고, pullulanase 처리한 결과 말토오스와 말토헥사오스까지의 분포를 나타내어 멥쌀식혜에서 얻은 한계덱스트린가 구조가 같은 결과이다. 밥알의 당함량은 26.4%, 단백질 함량은 41.6%를 나타냈다. 참쌀식혜의 한계덱스트린과 밥알에 30unit/ml의 $\alpha$-아밀라아제, 글\ulcorner아밀라아제, $\alpha$-글루코시다아제, $\beta$-아밀라아제를 작용시킨 결과 글루코아밀라아제 외에는 일부밖에 가수분해하지 at하였다. 인체의 효소인 $\alpha$-아밀라아제와 $\alpha$-글루코시다아제를 함께 작용시킨 결과 한계덱스트린의 가수분해율은 18%, 밥알의 가수분해율은 26%를 나타냈다.

• Bulletin of the Korean Chemical Society
• /
• 제14권2호
• /
• pp.200-206
• /
• 1993

Structures of two polymorphs of ${\alpha},{\alpha}$-trehalose octaacetate monohydrate, $C_{28}H_{38}O_{19}\;{\cdot}\;H_2O$, have been studied by X-ray diffraction method. ${\alpha},{\alpha}$-trehalose (${\alpha}$-D-glucopyranosyl ${\alpha}$-D-glucopyranoside) is a nonreducing disaccharide. The polymorph I belongs to the monoclinic $P2_1$, and has unit cell parameters of a=10.725(l), b=15.110(4), c=11.199(5) ${\AA}$, ${\beta}=108.16(2)^{\circ}$ and Z=2. The polymorph II is orthorhombic $P2_12_12_1$, with a=13.684(4), b=15.802(4), c=17.990(9) ${\AA}$ and Z=4. The final R and R$_w$ values for monoclinic polymorph I are 0.043 and 0.048 and for orthorhombic polymorph II are 0.116 and 0.118, respectively. Those R values of polymorph II are high because the large thermal motions of acetyl groups and the poor quality of the crystal. The molecular conformations in the two polymorphs are similar. Both D-glucopyranosyl rings have chair $^4C_1$ conformations and atoms of glycosidic chain ${\alpha}(1{\rightarrow}1)$ linkage are coplanar. The primary acetate groups of the pyranose residues assume both gauche-trans conformations. The molecules of two polymorphs have pseudo-C$_2$ symmetry at glycosidic O(1) atom. The bond lengths and angles are normal compared with those in other acetylated sugar compounds. The molecules in the monoclinic crystal are held by the hydrogen bonds with the water molecules and by van der Waals forces.

• 한국미생물·생명공학회지
• /
• 제16권4호
• /
• pp.259-264
• /
• 1988

Pseudomonas sp.로 동정된 토양분리균의 inulinase를 ammonium sulfate 분획, DEAE Sephadex A-50 Chromatography, Sephadex G 100 및 Sephadex G200 gel여과 등의 과정을 거쳐 정제 한 결과 inulinase PI과 PII의 두 isoenzyme으로 분리되었으며 각각 약 24배와 17배 정제되어 단일단백질로 분리되었다. PI, PII 두 isoenzyme은 다같이 sucrose, raffinose 및 levan은 분해하지 못하고 inulin만을 endo-type로 분해 절단하는 $\beta$-2,1-fructanfructano hydrolase(EC 3.2.1.7)임이 밝혀졌다. 효소활성 최적온도는 두 효소가 같은데 비해 (55$^{\circ}C$), 최적 pH는 PI이 pH5.5, PII가 pH6.0으로 약간의 차이를 보였다. Inulin에 대한 Km값은 PI ; 2$\times$$10^{-3}$M, PII : 5$\times$$10^{-3}$M로써 PI효소가 PII보다 약간 높은 친화력을 보였다.

• 한국식품영양학회지
• /
• 제10권1호
• /
• pp.92-96
• /
• 1997

시판 식혜에는 설탕과 프룩토오스, 글루코오스, 말토오스 및 여러 사이즈의 말토올리고당, 한계덱스트린이 함유되어 있다. 그 중 한계덱스트린은 0.09%, 밥알은 0.2%를 나타냈다. 1H-NMR 분석 결과, 한계덱스트린은 $\alpha$-1,4-결합 및 $\alpha$-1,6-결합이 15:1의 비율을 나타냈다. Pullulanase 처리로, 말토오스에서 글루코오스 10잔기 이상의 말토올리고당까지 다양한 분포를 나타냈다. 한계덱스트린은 여러 아미라아제 처리 결과, 전통식혜보다 가수분해율이 훨씬 높았다. $\alpha$-글루코시다아제와 타액 $\alpha$-아밀라아제를 공동 작용시킨 경우는 62% 가수분해되었다. 그러나, 밥알의 가수분해율이 매우 낮았다. 그래서 전통 식혜에 비해 한계덱스트린의 비피두스 인자로서의 효과는 적고, 밥알의 식이섬유 작용은 커졌다.

• Journal of Audiology & Otology
• /
• 제23권1호
• /
• pp.20-26
• /
• 2019

Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

• 대한청각학회지
• /
• 제23권1호
• /
• pp.20-26
• /
• 2019

Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

• 약학회지
• /
• 제11권1_2호
• /
• pp.7-16
• /
• 1967

A yellowish microneedles, $C_{28}$ H$_{32}$ $O_{14}$ ${\cdot}$ I$_{1}$/$_2$, H$_{2}$O, m.p.262-$4^{\circ}$ , [${\alpha}$$_{D}^{20}$= -71,$43^{\circ}$(C = 0.42, pyridine), its acetate m.p.123-5.deg., were obtained in 0.3% yield from the leaves of Chrysanthemum sibiricum F$_{ISCHER}$. This substance is insoluble in water and the usual organic solvents except pyridine and ethylene glycol and, is not decomposed by dilute mineral acids but undergoes decomposition on being boiled in 60% H$_{2}$SO$_{4}$ or 35% HCl, giving one moel each of acacetin, glucose and rhamnose. It was not hydrolysed with a rhamnodiastase preparation obtained from the seeds of Rhamnus koraiensis. After permethylation of it, the uncrystallized product was hydrolysed and apigenin-5,4'-dimethyl ehter, m.p.$262^{\circ}$ was obtained, indicating that the disaccharide residue is at the 7 position of acacetin. Partial hydrolysis of this acacetin-7-rhamnoglucoside in cyclohexanol with formic acid gave acacetin-7-glucoside, m.p.246.deg. and rutinose, identifying them with authentic specimen on a paper chromatography. It was thus identified as linarin(acacetin-7-rutinoside) by means of mixed fusion, of paper partition chromatography and of its derivatives. Zemplen and Bognar suggested that the glucosidic linkage of linarin is .betha. by means of synthesis of this substance. But there is no evidence whether it is hydrolysed by emulsin or maltase or not. Linarin itself was not hydrolysed by an emulsin existing in the seed of Apricot or a maltase, but acacetin-7-glucoside(tilianin) which obtained from linarin gave acacetin and glucose on hydrolysis with the same emulsin and accordingly the glucosidic linkages of linarin and tilianin are thus regarded as ${\beta}$.

• Journal of Applied Biological Chemistry
• /
• 제52권4호
• /
• pp.157-162
• /
• 2009

한천분해세균 SC-22균을 대전 대청댐부근의 담수에서 분리하였다. 생화학적 분석 및 16S rRNA 염기서열 분석을 통한 계통학적 분류를 통해 SC-22는 Cellvibrio mixtus로 동정되었다. 분리균의 생육 및 agarase 효소 생성능을 검토한 결과, SC-22는 탄소원으로 0.2% agar를 첨가한 배지에서 배양 36시간에 최대 생육을, 배양 48시간에 58.5 units/mL의 최대 효소활성을 나타내었다. 분리균은 세포외 및 세포내 agarase를 생성하였으며, zymogram 실험에 의해 P1, P2 및 P3의 isoenzyme을 분비하는 것으로 확인 되었다. 배양여액으로부터 겔여과법과 이온교환수지법을 단계적으로 이용하여 SC-22 균주로부터 SDS-PAGE에 의해 25 kDa의 효소를 정제하였으며, 정제효소는 zymogram에서 확인된 주 단백질인 P2(29 kDa)과 동일한 단백질임이 확인되었다. 또한 정제한 agarase의 효소학적 성질을 검토한 결과, 효소의 최적 pH와 최적온도는 pH 7.0과 $50^{\circ}C$이었으며, 금속이온 효과의 경우 1 mM 농도의 수준에서도 $Fe^{2+}$, $Na^+$, $Ca^{2+}$ 이온 등은 정제효소의 활성을 10-20% 증가시킨 반면 $Hg^{2+}$, $Mn^{2+}$ 및 $Cu^{2+}$ 이온들은 효소 활성을 크게 저해하였다. 또한 TLC 분석을 통해 정제효소는 한천 분해 올리고당으로 주로 단당류와 이당류를 생성하므로 $\beta$-agarase의 작용특성을 보였다. 기질특이성 실험에서는 정제효소는 agar와 agarose만을 이용 하였고 유사 해조 다당류인 alginate는 물론 다른 다당류를 분해하지 못하였다.

• 생명과학회지
• /
• 제10권3호
• /
• pp.307-316
• /
• 2000

Bacillus circualans S-1으로부터 새로운 균체외 pullulan 6-glucanohydrolase(EP)를 정제하였다. 정 제된 EP는 SDS하에서 140kDa의 분자량을 나타내었으며, pI는 5.5이었다. SDS-PAGE에 의해 분석된 이 EP는 Schiff staining에 대하여 negative이었으며, 또한 아미노 말단기 순서는 P-L-N-M-S-Q-P이었 다. 정제된 EP는 6$0^{\circ}C$ 부근의 최적온도와 pH 9.0 부근에서 최적 pH를 나타내었으며, pH 4.0에서 pH 11 까지 4$^{\circ}C$에서 24시간동안 반응에서도 안정하였다. 또한 기질로 사용된 Pullulan은 열불안정화로부터 효 소를 보호하였으며, 그 범위는 기질 농도에 의존하였다. 이 EP의 활성은 Mn2+, Ca2+ 이온 에 의하여 활성화되었으며, amylopectin, glycogen, $\alpha$,$\beta$-limited dextrin 및 pullulan의 $\alpha$-1,6-linkage를 가수분해 하였다. 정제된 EP는 pH 9.0 및 5$0^{\circ}C$에서 측정하였을 때 pullulan의 경우는 7.92mg/ml의 Km값을 각각 나타내었다. 또한 정제된 EP는 pullulan을 maltotriose까지 완전히 가수분해하였다. 그리고 Mouse anti-serum과 함께 western blotting 분석결과 정제된 EP는 배양과정중 단일 형태로 생산되는 것으로 나타났다.