http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Gattis, Samuel G.,Chung, Hak Suk,Trent, M. Stephen,Raetz, Christian R. H. American Society for Biochemistry and Molecular Bi 2013 The Journal of biological chemistry Vol.288 No.13
<P>Lipopolysaccharide (LPS; endotoxin) is an essential component of the outer monolayer of nearly all Gram-negative bacteria. LPS is composed of a hydrophobic anchor, known as lipid A, an inner core oligosaccharide, and a repeating O-antigen polysaccharide. In nearly all species, the first sugar bridging the hydrophobic lipid A and the polysaccharide domain is 3-deoxy-<SMALL>d</SMALL>-manno-octulosonic acid (Kdo), and thus it is critically important for LPS biosynthesis. Modifications to lipid A have been shown to be important for resistance to antimicrobial peptides as well as modulating recognition by the mammalian innate immune system. Therefore, lipid A derivatives have been used for development of vaccine strains and vaccine adjuvants. One derivative that has yet to be studied is 8-amino-3,8-dideoxy-<SMALL>d</SMALL>-manno-octulosonic acid (Kdo8N), which is found exclusively in marine bacteria of the genus <I>Shewanella</I>. Using bioinformatics, a candidate gene cluster for Kdo8N biosynthesis was identified in <I>Shewanella oneidensis</I>. Expression of these genes recombinantly in <I>Escherichia coli</I> resulted in lipid A containing Kdo8N, and <I>in vitro</I> assays confirmed their proposed enzymatic function. Both the <I>in vivo</I> and <I>in vitro</I> data were consistent with direct conversion of Kdo to Kdo8N prior to its incorporation into the Kdo8N-lipid A domain of LPS by a metal-dependent oxidase followed by a glutamate-dependent aminotransferase. To our knowledge, this oxidase is the first enzyme shown to oxidize an alcohol using a metal and molecular oxygen, not NAD(P)<SUP>+</SUP>. Creation of an <I>S. oneidensis</I> in-frame deletion strain showed increased sensitivity to the cationic antimicrobial peptide polymyxin as well as bile salts, suggesting a role in outer membrane integrity.</P>
Biotransformation of quercetin to quercetin 3-O-gentiobioside using engineered Escherichia coli
Cho, A Ra,An, Dae Gyun,Lee, Youngshim,Ahn, Joong-Hoon The Korean Society for Applied Biological Chemistr 2016 Applied Biological Chemistry (Appl Biol Chem) Vol.59 No.5
Various flavonoid O-diglycosides are found in nature but the biological activities of only a few compounds have been explored due to difficulty in obtaining samples. In order to circumvent the need for extraction and purification of the natural compounds from plants, we used engineered Escherichia coli strain that harbors two uridine diphosphate-dependent glycosyltransferases (UGTs; BcGT1 andCaUGT) and two nucleotide sugar biosynthetic genes (pgm and galU). Using this strain, we synthesized quercetin 3-O-gentiobioside. After optimization of induction temperature, cell density, and reaction temperature, approximately 46.2 mg/L quercetin 3-O-gentiobioside was synthesized from quercetin with 49 % conversion efficiency.
Biotransformation of quercetin to quercetin 3-O-gentiobioside using engineered Escherichia coli
조아라,안대균,이영심,안중훈 한국응용생명화학회 2016 Applied Biological Chemistry (Appl Biol Chem) Vol.59 No.5
Various flavonoid O-diglycosides are found in nature but the biological activities of only a few compounds have been explored due to difficulty in obtaining samples. In order to circumvent the need for extraction and purification of the natural compounds from plants, we used engineered Escherichia coli strain that harbors two uridine diphosphatedependent glycosyltransferases (UGTs; BcGT1 and CaUGT) and two nucleotide sugar biosynthetic genes (pgm and galU). Using this strain, we synthesized quercetin 3-O-gentiobioside. After optimization of induction temperature, cell density, and reaction temperature, approximately 46.2 mg/L quercetin 3-O-gentiobioside was synthesized from quercetin with 49 % conversion efficiency.