http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Novel $\alpha$-Glucosidase from Extreme Thermophile Thermus caldophilus GK24
Nashiru, Oyekanmi,Koh, Suk-Hoon,Lee, Se-Yong,Lee, Dae-Sil Korean Society for Biochemistry and Molecular Biol 2001 Journal of biochemistry and molecular biology Vol.34 No.4
$\alpha$-Glucosidase of an extreme thermophile, Thermus caldophilus GK24 (TcaAG), was purified 80-fold from cells to a homogeneous state and characterized. The enzyme exhibited optimum activity at pH 6.5 and $90^{\circ}C$, and was stable from pH 6.0 to 85 and up to $90^{\circ}C$. The enzyme had a half-life of 85 minutes at $90^{\circ}C$. An analysis of the substrate specificity showed that the enzyme hydrolyzed the non-reducing terminal unit of $\alpha$-1,6-glucosidic linkages of isomaltosaccharides and panose, $\alpha$-1,3-glycosidic bond of nigerose and turanose, and $\alpha$-1,2-glycosidic bond of sucrose. The gene encoding the TcaAG was cloned, sequenced, and sequenced in E. coli. The nucleotide sequence of the gene encoded a 530 amino acid polypeptide and had a G+C content of 68.4% with a strong bias for G or C in the third position of the codons (93.6%). A sequence analysis revealed that TcaAG belonged to the $\alpha$-amylase family. We suggest that this monomeric, thermostable, and broad-acting $\alpha$-glucosidase is a departure from previously exhibited specificities. It is, therefore, a novel $\alpha$-glucosidase.
( Won Jeong Lee ),( Jae Sun Moon ),( Sung In Kim ),( Young Tae Kim ),( Oyekanmi Nash ),( Yong Sun Bahn ),( Sung Uk Kim ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.10
In order to discover and develop novel signaling inhibitors from plants, a screening system was established targeting the two-component system of Cryptococcus neoformans by using the wild type and a calcineurin mutant of C. neoformans, based on the counter-regulatory action of high-osmolarity glycerol (Hog1) mitogen-activated protein kinase and the calcineurin pathways in C. neoformans. Among 10,000 plant extracts, that from Harrisonia abyssinica Oliv. exhibited the most potent inhibitory activity against C. neoformans var. grubii H99 with fludioxonil. Bioassay-guided fractionation was used to isolate two bioactive compounds from H. abyssinica, and these compounds were identified as chebulagic acid and chebulanin using spectroscopic methods. These compounds specifically inhibited the calcineurin pathway in C. neoformans. Moreover, they exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentrations ranging from 0.25 to over 64 μg/ml.
Novel α - Glucosidase from Extreme Thermophile Thermus caldophilus GK24
Lee, Se Yong,Lee, Dae Sil,Koh, Suk Hoon,Nashiru, Oyekanmi 생화학분자생물학회 1976 BMB Reports Vol.34 No.4
α-Glucosidase of an extreme thermophile, Thernius caldophilus GK24 (TcaAG), was purified 80-fold from cells to a homogeneous state and characterized. The enzyme exhibited optimum activity at pH 6.5 and 90℃, and was stable from pH 6.0 to 85 and up to 90℃. The enzyme had a half-life of 85 minutes at 90℃. An analysis of the substrate specificity showed that the enzyme hydrolyzed the non-reducing terminal unit of α-1,6-glucosidic linkages of isomaltosaccharides and panose, α-1,3-glycosidic bond of nigerose and turanose, and α-1,2-glycosidic bond of sucrose. The gene encoding the TcaAG was cloned, sequenced, and enpressed in E. coli. The nucleotide sequence of the gene encoded a 530 amino acid polypeptide and had a G+C content of 68.4 % with a strong bias for G or C in the third position of the codons (93.6 %). A sequence analysis revealed that TcaAG belonged to the aamylase family. We suggest that this monomeric, thermostable, and broad-acting α-glucosidase is a departure from previously exhibited specificities. It is, therefore, a novelα-glucosidase.
Jin, Yena,Yoon, Yae Jin,Jeon, Yoon Jung,Choi, Jiyeon,Lee, Yu-Jin,Lee, Joonku,Choi, Sangho,Nash, Oyekanmi,Han, Dong Cho,Kwon, Byoung-Mog Pergamon Press 2017 Biochemical pharmacology Vol.142 No.-
<P><B>Abstract</B></P> <P>The roles and significance of signal transducer and activator of transcription 3 (STAT3) in human cancers have been extensively studied and STAT3 is a promising therapeutic target for cancer drug discovery. During the screening of natural products to identify STAT3 inhibitors, we identified geranylnaringenin (CG902), which decreased luciferase activity in a dose-dependent manner. CG902 specifically inhibited STAT3 phosphorylation at Tyr-705 in DU145 prostate cancer cells and decreased the expression levels of STAT3 target genes, such as cyclin D1, cyclin A, and survivin. Notably, the knockdown of the SHP-2 gene by small interfering RNA suppressed the ability of CG902 to inhibit STAT3 activation and CG902 activated the phosphatase activity of SHP-2 through direct interaction with SHP-2 and induced the phosphorylation of SHP-2. The interactions between CG902 and SHP-2 were confirmed by pull-down assay using biotinylated CG902. The interactions were also further validated by the drug affinity responsive target stability (DARTS) and cellular thermal shift assay (CETSA). The inhibitory effect of CG902 on cell growth was confirmed using the DU145 mouse xenograft model. We propose that CG902 inhibits STAT3 activity through a mechanism that involves the interactions between CG902 and SHP-2, and the phosphorylation of SHP-2, which leads to SHP-2 activation in DU145 cells. CG902 is the first compound to regulate STAT3 activity via the modulation of SHP-2 activity, and our results suggest that CG902 is a novel inhibitor of the STAT3 pathway and an activator of SHP-2, and may be a useful lead molecule for the development of a therapeutic STAT3 inhibitor.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>