• BMB Reports
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• 제31권4호
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• pp.364-369
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• 1998

Insect plasma protein is abundant in the hemolymph of holometabolous insect larvae and is used as a source of amino acids and energy for construction of adult structures during metamorphosis. In order to understand the mechanism of decomposition of larval plasma proteins by hemocyte protease, we tried to purify a cysteine protease from the hemocyte lysate by using Carbobenzoxy-L-Phenylalanyl-L-Arginine-4-Methyl-Coumaryl-7-Amide (Z-Phe-Arg-MCA) as substrate and to identify plasma proteins that are selectively susceptible to the purified protease. Here, we describe the purification and characterization of a cysteine protease that specifically hydrolyzes the plasma protein of the coleopteran insect, Tenebrio molitor, larvae. The molecular mass of this enzyme was 25 kDa, as determined by SDS-PAGE under reducing conditions. The amino acids sequence of its $NH_{2}-terminus$ was determined to be Leu-Pro-Gly-Gln-Ile-Asp-Trp-Arg-Asp-Lys-Gly. This sequence contained Pro, Asp, and Arg residues, conserved in many papain superfamily enzymes. The specific cysteine protease inhibitors, such as E-64 and leupetin, inhibited its hydrolytic activity. One plasma protein with a molecular mass of 48 kDa was selectively hydrolyzed within 3 h when the purified enzyme and plasma proteins were incubated in vitro. However, the 48 kDa protein was not hydrolyzed by the purified 25 kDa protease in the presence of E-64. Western blotting analysis at various developmental stages showed that the purified enzyme was detected at larvae, pupae, and adult stages, but not the embryo stage.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.639-644
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• 1998

Extracellular serine proteases were isolated from a soil bacterium, alkalophilic coryneform bacterium TU-19, which have been grown in a liquid medium optimized at 3$0^{\circ}C$ and pH 10.0. Three different sizes, 120 kDa (protease I), 80 kDa (protease II), and 45 kDa (protease III), of serine pro teases were purified using Sephadex G-150 and QAE-Sephadex chromatography (Kang et al. 1995. Agric. Chem Biotech. 38: 534-540). SDS-PAGE showed that the 120 kDa protease was degraded into the 80 kDa protease in 20 mM Tris-HCI (pH 8.0) buffer solution. This degradation was enhanced in the presence of 0.5 M NaCl and 5 mM EDTA, but was inhibited in the presence of 5 mM $CaCl_2$. These results indicated that the $Ca^{2＋}$ ion seems to stabilize the 120 kDa protease like other proteases derived from Bacillus species. The $NH_2$-terminal amino acid sequences of the 10 residues of both proteases were completely identical: Met-Asn-Thr-Gln-Asn-Ser-Phe-Leu-Ile-Lys. In contrast to this, the 80 kDa protease has 1.5 times higher specific activity than the 120 kDa protease does (Kang et al. 1995. Agric. Chern. Biotech. 38: 534-540). Therefore the C-terminal of the 120 kDa protease seems to be autolyzed to the 80 kDa protease but this autolysis did not decrease the protease activity. Optimum pH and temperature of both 80 kDa and 120 kDa proteases were pH 10.5 and $45^{\circ}C$, respectively, and pH and thermal stability were almost identical. Several divalent ions except the $Fe^{2＋}$ ion showed similar effects on activities of both proteases, which are similarly resistant to three different detergents.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1011-1017
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• 2001

Streptomyces sp. Y-110 cytochrome P-450, induced by the addition of compactin -Na into the culture medium, was purified from the cell extract to apparent homogeniety, mainly by DEAE-Sepharose, hydroxyapatite, and Mono Q column chromatyography. The sepcific activity of purified enzyme on its substrate, compactin-Na, was determined to be 15 nmol of pravastatin per mg protein. The molecular mass of this enzyme on SDS-PAGE was $37{\pm}0.5$ kDa, pI was 4.5, and its CO difference spectrum showed maximum absorption peaks at 452 and 550nm, respectively. The N-terminal amino acid sequence was determined to be Met>Thr>Cys>Thr>Pro>Val>Thr>Val>The>Gly>Ala>Ala>Gly>Gln>Ile>Gly>Tyr>Ala>Leu. Its apparent $K_m$ on compactin-Na was $1.294{\mu}M{\cdot}min^-1,\;and\;V_{max}\;was\;1.028{\mu}M{\cdot}min^-1$. The maximum substrate concentration ($K_s$) for reaction was $270 {\mu}M$and thus $1/[K_s]$ was $3.7{\mu}M$. These physicochemical characteristics and kinetic behavior of this enzyme were compared and shown to be different from those of Streptomyces cytochrome P-450 enzymes reported, suggesting that this enzyme may be an additional member of the Streptomyces cytochrome P-450 family.

• Molecular & Cellular Toxicology
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• 제5권2호
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• pp.160-164
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• 2009

Notch signaling plays a crucial role in development of the nervous system. Neurodevelopmental hypothesis on etiology of schizophrenia has been implicated. The aim of this study is to determine whether single nucleotide polymorphisms (SNPs) of Notch homolog 4 (Drosophila) (NOTCH4) gene are associated with schizophrenia. This study included 283 schizophrenia patients diagnosed according to DSM-IV and 301 normal control subjects. Control subjects without history of psychiatric disorders were recruited. Four missense SNPs [rs915894 (exon 3, Lys117Gln), rs2071282 (exon 4, Pro204Leu), rs422951 (exon 6, Thr320Ala), and rs17604492 (exon 18, Gly942Arg)] of NOTCH4 gene were genotyped by the direct sequencing method. Multiple logistic regression models (codominant, dominant, and recessive models) were employed to evaluate odds ratio, 95% confidence interval, and p value. For analysis of genetic data, SNPStats, Haploview, HapAnalyzer, SNPAnalyzer, and Helixtree programs were also used. Of 4 SNPs, rs2071282 was weekly associated with schizophrenia in two alternative models (codominant model, P=0.049; dominant, P=0.041). However, these associations were not significant after Bonferroni correction. At 4 SNPs, one linkage disequilibrium (LD) block was made. This block consisted of rs915894 and rs2071282. In haplotype analysis, AC haplotype was weakly associated with schizophrenia (dominant, P=0.04). This association was disappeared after Bonferroni correction. Our result shows possibility that some SNPs of NOTCH4 gene may be weekly associated with development of schizophrenia in Korean population. However, replication result by other population will be needed.

• Archives of Pharmacal Research
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• 제29권5호
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• pp.418-423
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• 2006

Tabanus anticoagulant protein (TAP) was isolated from the whole body of the tabanus, Tabanus bivittatus, using three purification steps (ammonium sulfate fractionation, gel filtration on Bio-Gel P-60, and ion exchange chromatography on DEAE Sephadex gel). The purified TAP, with a molecular weight of 65 kDa, was assessed to be homogeneous by SDS-polyacrylamide gel electrophoresis, and an isoelectric point of 7.9 was determined by isoelectric focusing. The internal amino acid sequence of the purified protein was composed of Ser-Leu-Asn-Asn-Gln-Phe-Ala-Ser-Phe-lle-Asp-Lys-Val-Arg. The protein was activated by $Cu^{2+}\;and\;Zn^{2+}$, and the optimal conditions were found to be at pH $3\sim6\;and\;40\sim70^{\circ}C$. Standard coagulation screen assays were used to determine thrombin time and activated partial thromboplastin time. Chromogenic substrate assays were performed for thrombin and factor Xa activity. TAP considerably prolonged human plasma clotting time, especially activated partial thromboplastin time in a dose-dependent manner; it showed potent and specific antithrombin activity in the chromogenic substrate assay. Specific anti-factor Xa activity in TAP was not detected. Overall, this result suggested that TAP has significant anticoagulant activity on blood coagulation system.

• Journal of Life Science
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• 제9권1호
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• pp.26-34
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• 1999

A thermostable pullulanase has been isolated and purified from Thermus caldophilus GK-24 to a homogeneity by gel-filtration and ion-exchange chromatography. The specific activity of the purified enzyme was 431-fold increase from the crude culture broth with a recovery of 11.4%. The purified enzyme showed $M_{r}$ of 65 kDa on denaturated and natural conditions. The pI of the enzyme was 6.1 and Schiff staining was negative, suggesting that the enzyme is not a glycoprotein. The enzyme was most active at pH 5.5. The activity was maximal at $75^{\cire}C$ and stable up to $95^{\cire}C$ for 30 min at pH 5.5. The enzyme was stable to incubation from pH 3.5 to pH 8.0 at $4^{\cire}C$ for 24hr. The presence of pullulan protected the enzyme from heat inactivation, the extent depending upon the substrate concentration. The activity of the enzyme was simulated by $Mn^{2+}$ ion, }$Ni^{2+}$, $Ca^{2+}$, $Co^{2+}$ ions. The enzyme hydrolyzed the ${\alpha}$-1,6-linkages of amylopectin, glycogens, ${\alpha}$, ${\beta}$-limited dextrin, and pullulan. The enzyme caused the complete hydrolysis of pullulan to maltotriose and the activity was inhibited by $\alpha$, $\beta$, or $\gamma$-cyclodextrins. The $NH_{2}$-terminal amino acid sequence [(Ala-Pro-Gln-(Asp of Tyr)-Asn-Leu-Leu-Xaa-ILe-Gly-Ala(Ser)] was compared with known sequences of various sources and that was compared with known sequences of various sources and that was different from those of bacterial and plant enzymes, suggesting that the enzymes are structurally different.

• 농업과학연구
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• 제39권2호
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• pp.219-226
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• 2012

The acyl-CoA dehydrogenase, C-2 to C-3 short chain (ACADS) gene is known to be related with fat metabolism, especially coverts the fat to the energy sources in cattle. In human, the mutations in this gene cause SCAD deficiency, which is one of the fatty acid metabolism disorders. The ACADS gene is located on bovine chromosome 17. The objective of this study was to identify SNPs in Hanwoo ACADS gene and identify the relationships with economic traits. In this study, two SNPs, T1570G SNP in exon 2 and G13917A SNP in exon 4, were observed. Moreover, in the coding region, 2 missense mutations, T (Cys) ${\rightarrow}$ G (Trp) mutation at 1570 bp and G (Arg) ${\rightarrow}$ A (Gln) mutation at 13917 bp, were observed. These mutations were subjected to the PCR-RFLP for typing 198 Hanwoo animals. The observed genotype frequency for T1570G was 0.135 (TT), 0.860 (TG) and 0.005 (GG), respectively. Also, 0.900 (GG) and 0.100 (GA) were observed for the G13917A mutation. The association of these SNPs with four economic traits, CW (Carcass Weight), BF (Backfat Thickness), LMA (Longissimus Muscle Area), MS (Marbling Score), were also observed. The results indicated that no significant results were observed in all four traits (P>0.05). This might indicate that further studies are ultimately needed to use the SNPs in ACADS gene in lager populations for effectively used for the marker assisted selection.

• 농업과학연구
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• 제21권1호
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• pp.22-27
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• 1994

주로 생약식물로서 야용되어온 구기자의 당, 아미노산, 지방산, 무기물 함량을 각각 분석한 결과는 다음과 같다. 구기자에는 3종의 당이 있었으며, 당 조성으로서는 건조 구기자(품종, 청양) 100g당 glucose, 5.36%:fructose, 5.81%:sucrose, 4.39이였다. 총 단백질은 일본 I이 11.3894%로서 가장 높았으며, Asp/Asn, Glu/Gln은 다른 아미노산보다 높은 함량을 나타냈다. 구기자의 주요 지방산은 linoleic, oleic, palmitic acids이었으며, 이들은 총 지방산의 82.98~89.64%를 차지하였다. 구기자의 무기물 함량은 다른 가지과 식물과 비교할 때 $Ca^{{+}{+}}$량이 약간 적었다. 중국 II는 다른 품종에 비하여 $Ca^{{+}{+}}$, $Fe^{{+}{+}}$함량이 높았다.

• Journal of Microbiology
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• 제39권2호
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• pp.95-101
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• 2001

In an effort to develop an efficient expression and secretion system for heterologous proteins in Aspergilius nidulans, the PCR-amplified coding sequence for alkaline pretense (AlpA) of A. oryzae was cloned into a fungal expression vector downstream of A. nidulans aicA (alcohol dehydrogenase) promoter to yield pRAAlp. Transformation of A. nidulans with pRAAlp gave stable transformants harboring various copy numbers (3 to 10) of integrated alpA gene, from among which 6 representatives were selected. On a medium containing 0.8% ammonium sulfate that represses the expression of the host's own pretense, the alcA prumoter-controlled AlpA expression was strongly induced by threonine but repressed by glucose. The level of AlpA secretion was highest (approximately 666 mU/ml) in transformant ALP6 containing the largest copy number integrated alpA. However, the level of AlpA secretion was not necessarily proportional to the copy numbers of the integrated alpA genes. The N-terminal sequence or the secreted mature AlpA was determined to be Gly-Leu-Thr-Thr-Gln-Lys-Ser and its molecular mass to be approximately 34 kDa, indicating that AlpA is properly processed by the removal of 121 N-terminal amino acids.

• 한국식품영양과학회지
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• 제38권6호
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• pp.801-806
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• 2009

본 연구는 transglutaminase 생산능이 우수한 토양유래방선균 strain YK-2를 TGase 최적생산배지에서 $28^{\circ}C$, 5일간 배양하여 얻은 배양여액으로 본 효소의 정제 및 정제된 효소의 효소화학적 특성에 관하여 검토한 것이다. 본 효소의 정제는 50% methanol precipitation, DEAE-Sephadex column chromatography의 정제 절차를 거쳐 56.5%의 수율로 정제되었고, 정제된 효소의 순도는 12.5% SDS-PAGE에서 단일 밴드를 나타내어, 서브유닛트의 분자량이 약 45,000 dalton으로 추정되는 호모형 효소인 것을 알 수 있었다. 정제된 TGase의 생화학적 제 특성을 검토한 결과, 등전점은 pH $6.0{\sim}7.0$ 부근에 있는 것으로 나타났으며, 본 효소의 기질인 CBZ-L-Gln-Gly 농도에 대한 Km치는 18.5 mM으로 추산되었다. 또한 금속이온 및 저해제의 영향으로는 $Hg^{++}$에 의해서 본 효소의 활성이 강하게 저해되었으나, DTT 및 mercaptoethanol에 의해 각각 293% 및 219% 활성이 증가하였다.