Enzymatic Acylation
Mostrando 13-24 de 29 artigos, teses e dissertações.
-
13. Isolation and characterization of Pseudomonas aeruginosa mutants blocked in the synthesis of pyoverdin.
We have isolated and characterized by chemical and enzymatic analyses three distinct types of pyoverdin-defective (pvd) mutants of Pseudomonas aeruginosa PAO1. The pvd-1 mutant is an L-N5-hydroxyornithine (L-N5-OH-Orn) auxotroph unable to hydroxylate L-ornithine (L-Orn) in a cell-free system and requiring L-N5-OH-Orn for pyoverdin production. The other two t
-
14. Comparison of x-ray crystal structures of an acyl-enzyme intermediate of subtilisin Carlsberg formed in anhydrous acetonitrile and in water
The x-ray crystal structures of trans-cinnamoyl–subtilisin, an acyl-enzyme covalent intermediate of the serine protease subtilisin Carlsberg, have been determined to 2.2-Å resolution in anhydrous acetonitrile and in water. The cinnamoyl–subtilisin structures are virtually identical in the two solvents. In addition, their enzyme portions are nearly indi
The National Academy of Sciences.
-
15. The final acylation step in Taxol biosynthesis: Cloning of the taxoid C13-side-chain N-benzoyltransferase from Taxus
The formation of several acyl groups and an amide group of Taxol is catalyzed by regioselective CoA thioester-dependent acyltransferases. Several full-length acyltransferase sequences, obtained from a cDNA library constructed from mRNA isolated from Taxus cuspidata cells induced for Taxol production with methyl jasmonate, were individually expressed in Esche
The National Academy of Sciences.
-
16. Separation of 1-acylglycerolphosphate acyltransferase and 1-acylglycerolphosphorylcholine acyltransferase of rat liver microsomes.
1-Acylglycerolphosphate acyltransferase (Ec 2.3.1-) and 1-acylglycerolphosphorylcholine acyltransferase (EC 2.3.1.23) of rat liver microsomes were separated from each other. The separation was achieved by sucrose density gradient centrifugation of the enzyme preparation that was obtained by solubilizing microsomes with a nonionic detergent, Triton X-100, and
-
17. Positional specificity of a phospholipase A activity induced by wounding, systemin, and oligosaccharide elicitors in tomato leaves
Phospholipase A (PLA) activity, as measured by the accumulation of (14)C-lysophosphatidylcholine in leaves of tomato plants, increased rapidly and systemically in response to wounding. The increase in PLA activity in the systemic unwounded leaves was biphasic in wild-type tomato plants, peaking at 15 min and again at 60 min, but the second peak of activity w
-
18. Sequence Divergence of Seryl-tRNA Synthetases in Archaea
The genomic sequences of Methanococcus jannaschii and Methanobacterium thermoautotrophicum contain a structurally uncommon seryl-tRNA synthetase (SerRS) sequence and lack an open reading frame (ORF) for the canonical cysteinyl-tRNA synthetase (CysRS). Therefore, it is not clear if Cys-tRNACys is formed by direct aminoacylation or by a transformation of serin
American Society for Microbiology.
-
19. A hydrocarbon ruler measures palmitate in the enzymatic acylation of endotoxin
The ability of enzymes to distinguish between fatty acyl groups can involve molecular measuring devices termed hydrocarbon rulers, but the molecular basis for acyl-chain recognition in any membrane-bound enzyme remains to be defined. PagP is an outer membrane acyltransferase that helps pathogenic bacteria to evade the host immune response by transferring a p
Nature Publishing Group.
-
20. Metabolic fate of arachidonic acid in hepatocytes of continuously endotoxemic rats.
The present experiments were designed to characterize the kinetics of [1-14C]arachidonic acid (AA) metabolism as a function of time in hepatocytes obtained from rats infused continuously for 30 h with a nonlethal dose of Escherichia coli endotoxin (ET). Chronic endotoxemia greatly reduces the ability of hepatocytes to utilize [1-14C]AA, which is reflected fr
-
21. Leishmania tarentolae contains distinct cytosolic and mitochondrial glutaminyl–tRNA synthetase activities
The intracellular distribution of glutaminyl–tRNA synthetases and their role in mitochondrial tRNA import were evaluated in the ancient eukaryote Leishmania tarentolae. The following results were obtained: (i) Glutaminyl–tRNA synthetase was detected in leishmanial mitochondria. This was unexpected because it has been postulated that, in organelles, Gln-t
The National Academy of Sciences of the USA.
-
22. Microwave-assisted sample preparation for rapid and sensitive analysis of H. pylori lipid A applicable to a single colony[S]
The lipid A of Gram-negative bacteria plays a major role in the pathogenesis of bacterial infections. Lipid A diversity is observed both in the number and length of fatty-acid side chains and in the presence of terminal phosphate residues and associated modifications. In this report, we describe a new sample preparation method based on microwave-assisted enz
The American Society for Biochemistry and Molecular Biology.
-
23. Endotoxin biosynthesis in Pseudomonas aeruginosa: enzymatic incorporation of laurate before 3-deoxy-D-manno-octulosonate.
Unlike Escherichia coli, living cells of Pseudomonas aeruginosa can complete the fatty acylation of lipid A when the biosynthesis of 3-deoxy-D-manno-octulosonate (Kdo) is inhibited (R. C. Goldman, C. C. Doran, S. K. Kadam, and J. O. Capobianco, J. Biol. Chem. 263:5217-5233, 1988). In this study, we demonstrate the presence of a novel enzyme in extracts of P.
-
24. Direct experimental evidence for kinetic proofreading in amino acylation of tRNAIle.
Kinetic proofreading is a reaction scheme with a structure more complicated than that of Michaelis kinetics, which leads to a proofreading for errors in the recognition of a correct substrate by an enzyme. We have measured the stoichiometry between ATP hydrolysis and tRNAIle charging, using the enzyme isoleucyl-tRNA synthetase [L-isoleucine:tRNAIle ligase (A