Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The study carried out consists of evaluating the results obtained for estimation of glucose and urea with a procedure the originality of which resides mainly in the use of preconditioned reagents, in the dry form, laid out on a support where the colour develops, proceeding to a reading by reflectometry and linearise the response by a procedure of calculation carried out by a microprocessor. The evaluation of the results obtained with the Kodak-Ektachem prototype for estimations of glucose and urea in the plasma was carried out according to the NCCLS protocol in the field of a coordinated European study. The imprecision was estimated at several levels of concentration after a study of intraserial and day to day reproducibility with and without contamination correction, the variation coefficients obtained from day to day are less than 3% when the concentrations of glucose and urea are higher than 5 mmol.l, the lower concentrations lead to less precision. No contamination was demonstrated. The inaccuracy is evaluated by comparison of the results supplied by the testing apparatus with those obtained by techniques chosen as reference. (Direct hexokinase with deduction of a blank sample and final reading at 340 nm for glucose, a colorimetric technique using monoxime diacetyl adapted to continuous flow for urea). The correlations between these methods are good : (mmol.l1) glucose : (EKTA) = 0.07 + 1,025 (HK); r = 0,993. Urea : (EKTA) = = 0,498 + 1,046 (DAM); r = 0,995. Further studies on the influence of proteins and a few physiological and drug substances liable to interfere have shown that a routine use in the laboratory may be considered favourably.
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PMID:[Evaluation according to the NCCLS protocol of the Kodak-Ektachem procedure applied to the estimation of glucose and urea in plasma (author's transl)]. 721 97

N-acetylglucosamine (GlcNAc) is the monomer of the polysaccharide chitin, an essential structural component of the fungal cell wall and the arthropod exoskeleton. We recently showed that the genes encoding the enzymes for GlcNAc catabolism are clustered in several ascomycetes. In the present study we tested these fungi for growth on GlcNAc and chitin. All fungi, containing the GlcNAc gene cluster, could grow on GlcNAc with the exception of four independent Neurospora crassa wild-type isolates, which were however able to grow on chitin. GlcNAc even inhibited their growth in the presence of other carbon sources. Genes involved in GlcNAc catabolism were strongly upregulated in the presence of GlcNAc, but during growth on chitin their expression was not increased. Deletion of hxk-3 (encoding the first catabolic enzyme, GlcNAc-hexokinase) and ngt-1 (encoding the GlcNAc transporter) improved growth of N. crassa on GlcNAc in the presence of glycerol. A crucial step in GlcNAc catabolism is enzymatic conversion from glucosamine-6-phosphate to fructose-6-phosphate, catalyzed by the glucosamine-6-phosphate deaminase, DAM-1. To assess, if DAM-1 is compromised in N. crassa, the orthologue from Trichoderma reesei, Trdam1, was expressed in N. crassa. Trdam1 expression partially alleviated the negative effects of GlcNAc in the presence of a second carbon source, but did not fully restore growth on GlcNAc. Our results indicate that the GlcNAc-catabolism pathway is bypassed during growth of N. crassa on chitin by use of an alternative pathway, emphasizing the different strategies that have evolved in the fungal kingdom for chitin utilization.
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PMID:N-acetylglucosamine, the building block of chitin, inhibits growth of Neurospora crassa. 2873 99