Authentic N omega-hydroxy-L-arginine was synthesized and used to determine whether it is an intermediate in nitric oxide (.NO) synthesis from L-arginine by macrophage .NO synthase. The apparent Km (6.6 microM) Vmax (99 nmol x min-1 mg-1) observed with were similar those (Km = 2.3 microM; 54 mumol mg-1). omega-Hydroxy-D-arginine not a substrate. Stable isotope studies showed that synthase exclusively oxidized the hydroxylated nitrogen of omega-hydroxy-L-arginine, forming L-citrulline. As...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExtremely Large Isotope Effects in the Soybean Lipoxygenase-Linoleic Acid ReactionMichael H. Glickman, Jeffrey S. Wiseman, and Judith P. KlinmanCite this: J. Am. Chem. Soc. 1994, 116, 2, 793–794Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/ja00081a060https://doi.org/10.1021/ja00081a060research-articleACS PublicationsRequest reuse...

Diaminopimelic acid epimerase was purified fromEscherichia coli.The enzyme is a monomer of M, = 34,000.Diaminopimelic not pyridoxal phosphate-dependent enzyme: there no evidence for phosphate in the ultraviolet spec- trum enzyme, and inactivated by carbonyl reagents such as hydroxylamine sodium borohydride.Exchange a- protons substrates, DL-and m-diaminopimelic acid, with solvent accompanies epimerization; exchange 3H from into diaminopimelic gives ' H primarily (80-90%) product isomer,...

Cytochrome P450 46A1 (CYP46A1) is a brain-specific cholesterol 24-hydroxylase responsible for the majority of elimination from brain. Genetically increased CYP46A1 expression in mice leads to improved cognition and decreases manifestations Alzheimer disease. We found that four pharmaceuticals (efavirenz (EFV), acetaminophen, mirtazapine, galantamine) prescribed indications unrelated maintenance activity vitro. then evaluated anti-HIV medication EFV mode interaction with effect on mice....

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism of inhibition aldehyde dehydrogenase by cyclopropanone hydrate and the mushroom toxin coprineJeffrey S. Wiseman Robert H. AbelesCite this: Biochemistry 1979, 18, 3, 427–435Publication Date (Print):February 6, 1979Publication History Published online1 May 2002Published inissue 6 February 1979https://pubs.acs.org/doi/10.1021/bi00570a006https://doi.org/10.1021/bi00570a006research-articleACS PublicationsRequest reuse permissionsArticle...

The interactions between (R)-rolipram and purified human recombinant low-Km, cAMP-specific phosphodiesterase (HSPDE4B2B) constructs were investigated using biochemical, kinetic, biophysical approaches. full-length protein (amino acids 1-564) an N-terminal truncated 81-564) exhibited high-affinity binding, whereas C-terminal 152-528) lacked binding. 152-528 81-564 proteins had similar Km's kcat/Km's differed less than 4-fold compared with the 1-564 protein. (R)-Rolipram inhibition plots...

Cyclopropanone hydrate irreversibly inactivates horseradish peroxidase in a time-dependent manner the presence of oxidizing agent, hydrogen peroxide. The inhibition reaction is second order cyclopropanone with compound I, 2 electron-oxidized form peroxidase, and results covalent modification heme cofactor. A new propionic acid side chain substituted for one methine protons heme. mechanism proposed to involve oxidative ring opening give primary free radical acid, which subsequently alkylates...

Tryptophan 2,3-dioxygenase (EC 1.13.1.12) is a hemoprotein which catalyzes the first step in oxidative degradation of tryptophan. The reaction believed to proceed by addition O2 across 2,3-bond indole ring, followed decomposition resultant dioxetane give N-formylkynurenine. A primary D2O isotope effect 4.4 on Vmax/Km was observed at pH optimum, 7.0. This implies that abstraction proton least partially rate-determining. An inverse secondary 0.96 for L-[2-3H]tryptophan this pH. signals...

The peptide substrate specificities of two matrix metalloproteinases (MMPs), interstitial collagenase (MMP-1), and 92-kDa gelatinase (MMP-9), have been examined. Starting with the parent substrate, Dnp-Pro-Leu-Gly approximately Leu-Trp-Ala-D-Arg-NH2, four separate mixtures were synthesized at subsites P2(Leu) through P2′(Trp). These contained either naturally occurring L-amino acids, D-amino or distinct sets miscellaneous amino acids. Combined, these gave 88 unique substitutions each...

Cytochrome P450 46A1 (cholesterol 24-hydroxylase) is an important brain enzyme that may be inhibited by structurally distinct pharmaceutical agents both in vitro and vivo. To identify additional inhibitors of CYP46A1 among U.S. Food Drug Administration-approved therapeutic agents, we used silico intuitive predictions evaluated some the predicted binders spectral binding assays. We tested a total 298 marketed drugs for inhibition CYP46A1-mediated cholesterol hydroxylation found 13 them reduce...

Abstract An early sign of islet failure in type 2 diabetes (T2D) is the loss normal patterns pulsatile insulin release. Disruptions pulsatility are associated with a left shift glucose sensing that can cause excessive release low (relative hyperinsulinemia, hallmark T2D) and β-cell exhaustion, leading to inadequate during hyperglycemia. Our hypothesis was reducing glucokinase activity diabetic islets would improve their function. Isolated mouse were exposed varying concentrations inhibitor...

Abstract A strategy is described for the rapid optimization of kcat/Km protease substrates. Selected positions a given peptide substrate sequence are varied through synthesis with mixtures amino acids. Incubation resulting mixture enzyme interest and analysis by high pressure liquid chromatography provides direct measure analogs enhanced kcat/Km. High performance chromatography/continuous flow fast atom bombardment mass spectrometry used to assign structure each peak in chromatogram. As an...

A fragment-based method for computing protein-ligand binding free energies by systematic sampling has been developed. Systematic of fragment-protein interactions in translational and rotational space is followed de novo assembly fragments into molecules computation the with statistical mechanics. The rigorous provides independence from choice initial pose assembling enables evaluation a large number molecule poses relatively little computation. allows full possible conformations avoids...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotolysis of 1-azido-2,2,3,4,4-pentamethylphosphetane 1-oxide. Monomeric metaphosphonimidateJeffrey Wiseman and F. H. WestheimerCite this: J. Am. Chem. Soc. 1974, 96, 13, 4262–4268Publication Date (Print):June 1, 1974Publication History Published online1 May 2002Published inissue 1 June 1974https://pubs.acs.org/doi/10.1021/ja00820a033https://doi.org/10.1021/ja00820a033research-articleACS PublicationsRequest reuse permissionsArticle...

The principles behind the computation of protein-ligand binding free energies by Monte Carlo simulation in Grand Canonical Ensemble are described detail, and two variations calculation presented. can be performed bathing a protein site either with ligand images that interact each other or pass through other. second method is theoretically more rigorous, but we show both methods lead to same result, there distinct numeric advantages using provides gas-phase converted aqueous generalized...

LLC-PK1 epithelial cells and RFL-6 fibroblasts secreted both cyclic AMP (cAMP) GMP (cGMP) when costimulated with forskolin 3-morpholinosydnonimine (a chemical nitric oxide generator). Intracellular cAMP levels as high 1100 12,000 pmol/10(6) were achieved for the two cell types, respectively. These enough to reach approximately 50% saturation of transporter inhibited transport cGMP an equal extent, suggesting that nucleotides compete a common system. The rates secretion from increased in...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT.alpha.-Secondary isotope effects in the lipoxygenase reactionJeffrey S. WisemanCite this: Biochemistry 1989, 28, 5, 2106–2111Publication Date (Print):March 7, 1989Publication History Published online1 May 2002Published inissue 7 March 1989https://pubs.acs.org/doi/10.1021/bi00431a021https://doi.org/10.1021/bi00431a021research-articleACS PublicationsRequest reuse permissionsArticle Views66Altmetric-Citations24LEARN ABOUT THESE METRICSArticle Views...

The diaminopimelic acid (DAP) analog, 3-chloro-DAP, was synthesized and tested as the racemic for antibacterial activity inhibition of DAP epimerase. 3-Chloro-DAP a potent inhibitor epimerase purified from Escherichia coli (Ki = 200 nM), it is argued that 3-chloro-DAP converted to tight-binding transition state analog at active site this enzyme. Furthermore, inhibited growth two E. mutants. In one mutants known supersusceptibility beta-lactams, not seen until mid-log phase growth, while in...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of the reaction cyclopropanone hydrate with yeast aldehyde dehydrogenase: a model for enzyme-substrate interactionJeffrey S. Wiseman, Guy Tayrien, and Robert H. AbelesCite this: Biochemistry 1980, 19, 18, 4222–4231Publication Date (Print):September 1, 1980Publication History Published online1 May 2002Published inissue 1 September 1980https://pubs.acs.org/doi/10.1021/bi00559a013https://doi.org/10.1021/bi00559a013research-articleACS...