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Application of Microbial Glycosidases and Transglycosidases in the Synthesis of Bioactive Glycosides
Jaeho Cha 한국당과학회 2008 한국당과학회 학술대회 Vol.2008 No.1
The glycosides are increasingly implicated in biological recognition and signalling mechanisms, thus further elevating their potential as therapeutics. This prominence creates a strong need for efficient and versatile methods for stereo- and regioselective glycoside synthesis. The enzymatic synthesis of glycosidic linkages with carbohydrate-active enzymes has been widely investigated to address this issue and is attractive in their abilities to circumvent often long-winded protection regimes. Glycosyltransferases have proven to be highly efficient in the synthesis of glycosidic linkages. However, the expense of the nucleotide sugar substrates, tight substrate specificity, and low enzyme availability limits their application. Glycosidases area attractive for large-scale application since they are more abundant, relatively inexpensive, exhibit broader acceptor-substrate specificity and use simpler substrates. However, stringent donor specificities and low yield can limit their use. In terms of reaction mechanism, transglycosidases and glycosidases belong to the same group. In this presentation we will focus on the use of transglycosidase and glycosidase for the synthesis of bioactive glycosides. The enzymes we chosen are levansucrase (transglycosidase) and β-glucosidase (glycosidase), respectively. The potential applications of newly made glycosides as well as the biochemical characteristics, substrate specificities, and transglycosylation properties of both enzymes can be discussed.
Molecular and enzymatic characterization of a levan fructotransferase from Microbacterium sp. AL-210
Cha, Jaeho,Park, Na Hee,Yang, Sung Jae,Lee, Tae Ho 부산대학교 유전공학연구소 2001 분자생물학 연구보 Vol.17 No.-
Microbacterium sp. AL-210 producing a novel levan fructotransferase (LFTase) was screened from soil samples. The LFTase was purified to homegeneity by (NH_4)_2SO_4 fractionation, column chromatography on Resource Q, and Superdex 200HR. The molecular weight of the purified enzyme was estimated to be approximately 46 kDa by both SDS-PAGE and gel filtration, and the enzyme's isoelecric point was pH 4.8. The major product produced from the levan hydrolysis by the enzyme reaction was identified by atmospheric pressure ionization mass spectrometry and NMR analysis as di-D-fructose-2,6':6,2'-dianhydride (DFA Ⅳ). The optimum pH and temperature for DFA Ⅳ production wer 7.0 and 40℃, respectively. The enzyme was stable at a pH range 7.0-8.0 and up to 40 ℃. The enzyme activity was inhibited by FeCl_2 and AgNO_3. The enzyme converted the levan to DFA Ⅳ, with a conversion yield of approximately 44%. A gene encoding the LFTase (lftM) from Microbacterium sp. AL-210 was cloned and sequenced. The nucleotide sequence included an ORF of 1593 nucleotides, which is translated into a protein of 530 amino acid residues. The predicted amino acid sequence of the enzyme shared 79% of the identity and 86% of the homology with that of Arthrobacter nicotinovorans GS-9. ⓒ 2001 Elsevier Science B.V. All rights reserved.
Patterns of care and treatment outcomes for primary thyroid lymphoma: a single institution study
Cha, Hyejung,Kim, Jun Won,Suh, Chang-Ok,Kim, Jin Seok,Cheong, June-Won,Lee, Jeongshim,Keum, Ki Chang,Lee, Chang Geol,Cho, Jaeho The Korean Society for Radiation Oncology 2013 Radiation Oncology Journal Vol.31 No.4
Purpose: The aim of this study was to analyze the patterns of care and treatment outcomes in patients with primary thyroid lymphoma (PTL) in a single institution. Materials and Methods: Medical records of 29 patients with PTL treated between April 1994 and February 2012 were retrospectively reviewed. Diagnosis was confirmed by biopsy (n = 17) or thyroidectomy (n = 12). Treatment modality and outcome were analyzed according to lymphoma grade. Results: The median follow-up was 43.2 months (range, 3.8 to 220.8 months). The median age at diagnosis was 57 years (range, 21 to 83 years) and 24 (82.8%) patients were female. Twenty-five (86.2%) patients had PTL with stage IEA and IIEA. There were 8 (27.6%) patients with mucosa-associated lymphoid tissue (MALT) lymphoma and the remaining patients had high-grade lymphoma. Patients were treated with surgery (n = 2), chemotherapy (n = 7), radiotherapy (n = 3) alone, or a combination of these methods (n = 17). Treatment modalities evolved over time and a combination of modalities was preferred, especially for the treatment of high-grade lymphoma in recent years. There was no death or relapse among MALT lymphoma patients. Among high-grade lymphoma patients, 5-year overall survival (OS) and 5-year progression-free survival (PFS) were 75.6% and 73.9%, respectively. Complete remission after initial treatment was the only significant prognostic factor for OS (p = 0.037) and PFS (p = 0.003). Conclusion: Patients with PTL showed a favorable outcome, especially with MALT lymphoma. Radiotherapy alone for MALT lymphoma and chemotherapy followed by radiotherapy for high-grade lymphoma can be effective treatment options for PTL.
<i>SERPINE2</i> Polymorphisms and Chronic Obstructive Pulmonary Disease
Cha, Seung Ick,Kang, Hyo-Gyoung,Choi, Jin Eun,Kim, Min Jung,Park, Jaeho,Lee, Won Kee,Kim, Chang Ho,Jung, Tae Hoon,Park, Jae Yong The Korean Academy of Medical Sciences 2009 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.24 No.6
<P>A number of genome-wide linkage analyses have identified the 2q33.3-2q37.2 region as most likely to contain the genes that contribute to the susceptibility to chronic obstructive pulmonary disease (COPD). It was hypothesized that the <I>SERPINE2</I> gene, which is one of the genes located at the 2q33.3-2q37.2 region, may act as a low-penetrance susceptibility gene for COPD. To test this hypothesis, the association of four <I>SERPINE2</I> single nucleotide polymorphisms (SNPs; rs16865421A>G, rs7583463A>C, rs729631C>G, and rs6734100C>G) with the risk of COPD was investigated in a case-control study of 311 COPD patients and 386 controls. The SNP rs16865421 was associated with a significantly decreased risk of COPD in a dominant model for the polymorphic allele (adjusted odds ratio [OR]=0.66, 95% confidence interval [CI]=0.45-0.97, <I>P</I>=0.03). In haplotype analysis, the GACC haplotype carrying the polymorphic allele at the rs16865421 was associated with a significantly decreased risk of COPD when compared to the AACC haplotype (adjusted OR=0.58, 95% CI=0.38-0.89, <I>P</I>=0.01), and this effect was evident in younger individuals (adjusted OR=0.30, 95% CI=0.14-0.64, <I>P</I>=0.002). This study suggests that the <I>SERPINE2</I> gene contributes to the susceptibility to COPD.</P>