Project description:This SuperSeries is composed of the following subset Series:; GSE4602: AML genome hybridization to HGU133 Plus 2.0; GSE4608: AML mRNA hybridization to HGU133 Plus 2.0 Experiment Overall Design: Refer to individual Series
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:The primary goal of this study was to compare the performances of Rhesus Macaque Genome Array and Human Genome U133 Plus 2.0 Array with respect to the detection of differential expressions when rhesus macaque RNA extracts were labeled and hybridized. The secondary goal of this study was to investigate the effect of mismatch position on signal strength in Affymetrix GeneChips by examining naturally occurring mismatches between rhesus macaque transcripts and human probes from Human Genome U133 Plus 2.0 Array. The primary goal of this study was to compare the performances of Rhesus Macaque Genome Array and Human Genome U133 Plus 2.0 Array with respect to the detection of differential expressions when rhesus macaque RNA extracts were labeled and hybridized. The secondary goal of this study was to investigate the effect of mismatch position on signal strength in Affymetrix GeneChips by examining naturally occurring mismatches between rhesus macaque transcripts and human probes from Human Genome U133 Plus 2.0 Array. Keywords: cross hybridization