... individual samples designated for processing for agricultural pesticides, hormones, pharmaceuticals, and the YES assay.The procedures used for preparing SPMD samples for analysis were similar ... held for 3 minutes, then ramped at 9 °C/min to 320 °C and held at 320 °C for 3 minutes. Identification of the targeted chemicals was performed using full-scan MS, and quantification was performed ... with the Friends of the North Fork of the Shenandoah RiverInvestigation of Organic Chemicals Potentially Responsible for Mortality and Intersex in Fish of the North Fork of the Shenandoah River,...
... except for UDP-GlcNAc acyltransferase, responsiblefor lipid A biosynthesis inM. catarrhalis, have been identified. By bioinformatics, two late acyltrans-ferase genes, lpxX and lpxL, responsiblefor ... m HCl at 80 °C for 18 h.The FAMEs were recovered into the organic phase bythree-fold extraction with 50% NaCl ⁄ chloroform (1 : 1v ⁄ v). A new volume of chloroform was used for each ofthe ... LpxM is responsible for the addition of a secondary myristate(C14:0) chain at the 3¢-position of lipid A [36,37]. InH. influenzae, the htrB (lpxL) gene product was shownto be responsiblefor the...
... post-hydrolysis. Therefore, the dissoci-ation of phosphate and ⁄ or ADP is likely to be responsiblefor resettingof the transporter. The data indicate that, like ABCB1 and ABCC1,the ‘power stroke’ for translocation ... inform on the orientation of the sites,only their affinity for interaction with drugs.The data presented here suggest that the ABC-G2R482Gisoform undergoes the following sequence ofconformational ... ABCB1, the R482G isoformalso contains multiple sites of interaction for a singledrug (daunomycin), which can manifest as homotropicallostery [22]. The latter has been observed for thebacterial...
... analmost 2000-fold decrease in the kcatvalue for dThd,and a 270-fold decrease for dCyd. The Kmvalue wasincreased sevenfold for dThd and 49-fold for dCyd.The large decrease in kcatvalue ... catalytic rate. For the E52Dmutant the Kmvalue was approximately the same as for the wild-type with dThd, whereas kcatwas 20 000times lower. This was also the scenario for the E52Hmutant ... ordered with formation ofa ternary complex [1,2]. Pre-steady-state measurementsindicate that either the catalytic step or a precedingstep is rate determining for the overall forward reac-tion...
... A novel coupled enzyme assay reveals an enzyme responsiblefor thedeamination of a chemically unstable intermediate in the metabolicpathway of 4-amino-3-hydroxybenzoic ... coupled assay wasidentified as 2-hydroxymuconic 6-semialdehyde by GC-MSanalysis. A mechanism for the formation of 2-hydroxy-muconic 6-semialdehyde via enzymatic deamination andnonenzymatic decarboxylation ... characterization of theenzymes is slow [2,4], p robably because the substrate for the enzyme assay, 2-aminomuconic 6 -semialdehyde, which i sformed by ring cleavage of 2-aminoph enol, is unstable and isconverted...
... & M artin [6], we also n eeded to obtaininformation ab out relevant noncoding regions in whichspecific and informative mutations are localized. For these reasons, we d ecided to analyse the ... M/B).Interestingly, the mutation s pecific for the M allele affectsthe same nucleotide as that which is deleted in the F allele,and shown to be responsiblefor the internal deletion of 37amino-acid ... ollowingthree-step cycle which was repeated 35 times: denaturation for 30 s (or 1 min) at 94 °C, annealing for 30 s (or 2 min) at47–60 °C, and extension for 30–60 s (or 3 min) at 72 °C,using the 2400 (or...
... determinant responsiblefor PKAphosphorylation in vitroTo identify the structural determinants that are respon-sible for phosphorylation of GIRK1 by PKA, fusionproteins comprising truncated forms ... mmolÆL)1glutathione pH 8.0.Immunoprecipitation For the immunoprecipitation experiments, Xenopus laevisoocytes were injected with cRNAs coding for GIRK1 andGIRK4 (5 ng per oocyte for each RNA) and the KHA2antisense ... proteinwas also demonstrated to be a direct target for PKA-catalysed phosphorylation [17,22,23]. Despite severalefforts undertaken to identify the responsible structuraldeterminant on the GIRK1...
... nuclear localization for the mSMOl isoform (Fig. 4).Taken together, these results consistently substanti-ate the hypothesis that these two structural regions aremandatory for the nuclear localization ... (2005) 3052–3059 ª 2005 FEBSTwo short protein domains are responsiblefor the nuclearlocalization of the mouse spermine oxidase l isoformMarzia Bianchi1, Roberto Amendola2, Rodolfo Federico1, ... that the two domains NDA andNDB, not involved in enzyme activity or FAD bind-ing, could be responsiblefor the interaction with thenuclear targeting machine. With this hypothesis inmind, we constructed...
... strain Iso1 was V. paradoxus .For example, the stain Isol was positive for catalase, oxidase andnitrate reduction but negative of hydrolysis for gelatin andstarch. Therefore, according to all above ... incubated at 37 °C overnight. The transformantswere screened for enzyme activity by adding to each well10 lL2mgÆmL)1lysozyme and incubating at 37 °Cfor30 min. This was followed by the addition ... mea-surements were performed at various temperatures for 20 min. Thehighest activity was taken as 100%. (B) Thermostability of purifiedenzyme. The purified enzyme was preincubation for 30 min at varioustemperatures....
... WÆm)2 for different times beforemycelia filtration. For carotenoid analysis of the strainsused in the expression experiments, incubations were per-formed for 7 days in the dark at 22 °C. For ... fujikuroi were formerly investigated in N. crassa (al-1[20], al-2 [21,22], and cao-2 [23], respectively).Recently, we identified in this fungus the gene ylo-1[24], which is responsiblefor the aldehyde ... evi-dence for this function, transformation experimentswere carried out to obtain null carD mutants ofF. fujikuroi by targeted gene replacement with ahygromycin resistance cassette (Fig. 6A). For...
... sequence as being responsiblefor the pecu-liar kinetic characteristics of this enzyme, acting as anegative determinant for malonyl-CoA sensitivity.Asp17 may account, at least in part, for the highdegree ... the single amino acid variation observedbetween pig and human (Asp17 for human and Glu17 for pig) might be responsiblefor the kinetic charac-teristics of both CPT1B enzymes. Consequently, ... scale) for IC50calculation. The Km for carnitine was obtained by assayingmitochondria in the presence of increasing carnitine concen-trations: 50–1500 lm for pig CPTIB, and 50–2000 l m for human...
... thiocoraline, the sulfhydryl groups of l-Cys3form a disulfide crossbridge minimizing conforma-tional freedom to a great extent. It can be assumedthat the oxidative formation of the crossbridge is car-ried ... biosynthesis, an oxidoreductase (Ecm17) isfound within the biosynthetic operon proposed to be responsible for disulfide formation [35]. This oxidore-ductase, although lacking in the gene cluster enablingthiocoraline ... The lack ofN-methylation of l-Cys3 ⁄ 4 is presumably responsible for the absence of DNA-bisintercalation activity.N-methylation induces conformational changes andelevates rotational barriers...
... active conformation, Val371 forms contactswith neighboring residues that are important for stabi-lizing the active state (e.g. Asp189, which is part of theS1 pocket responsiblefor the binding ... Sun MF, Cheng Q & Walsh PN(2001) Model for a factor IX activation complex on blood platelets: dimeric conformation of factor XIa isessential. Blood 97, 3117–3122.7 Yun TH, Baglia FA, Myles ... Declaration of Helsinki before blood withdrawal. Peripheral venous blood was collected in1 : 10 volume of 0.11 m trisodium citrate, pH 7.3. GenomicDNA was extracted from whole blood using a standardsalting-out...
... sites and ACP-induced cooperativity for theinteractions of the cofactor NADPH for these mutantshave been characterized for the first time in studiesreported here for Plasmodium FabG. We have usedACP-dependent ... reductaseand its implications for substrate binding and catalysis.Structure 8, 339–347.16 Zhang YM, Wu B, Zheng J & Rock CO (2003) Keyresidues responsiblefor acyl carrier protein and beta-ketoacyl-acyl ... not responsible for the content or functionality of any supplementarymaterial supplied by the authors. Any queries (otherthan missing material) should be directed to thecorresponding author for...
... concentration of0.5 mm. Cells were grown for a further 20 min and pouredinto cold tubes. All subsequent steps were performed at4 °C. After centrifugation at 1900 g for 10 min, the cellProtection of ... work as an inhibitor for the proteoly-sis of r32through direct interaction with the protease,characterized by a lack of interaction between r32andCIII (Fig. 4). As for CII, competition ... between r32andCIII for binding to HflB would also decide the extentand efficiency of protection of r32by CIII, becauseboth are HflB substrates. The relative binding affinity for r32–HflB interaction...