Effect of structural modifications on the activity of the leadzyme.

abstract：:We have obtained the 470 MHz 19F NMR spectra of wild type [4-F]Trp-labeled myoglobins (MbCO, MbO2, deoxyMb, metMb, and MbCN) and hemoglobins (HbCO, HbO2, and deoxyHb), as well as those of several mutants (W7F Mb, betaW15F Hb, betaW37S Hb, and betaY130F Hb, all as the carbonmonoxy adducts), prepared via site-directed m...

journal_title：Biochemistry

authors： Pearson JG,Montez B,Le H,Oldfield E,Chien EY,Sligar SG

更新日期：1997-03-25 00:00:00

abstract：:Bacterial cytochrome P450cam catalyzes the hydroxylation of camphor to yield 5-exo-hydroxycamphor in vivo and in a reconstituted system with oxygen, pyridine nucleotide, flavoprotein dehydrogenase, and putidaredoxin. Product is also formed when the ferric form of the hemoprotein is mixed with the exogenous oxidants io...

journal_title：Biochemistry

authors： Gelb MH,Heimbrook DC,Mälkönen P,Sligar SG

更新日期：1982-01-19 00:00:00

abstract：:Bacimethrin-derived 2'-methoxythiamin pyrophosphate inhibits microbial growth by disrupting metabolic pathways dependent on thiamin-utilizing enzymes. This study describes the discovery of the bacimethrin biosynthetic gene cluster of Clostridium botulinum A ATCC 19397 and in vitro reconstitution of bacimethrin biosynt...

journal_title：Biochemistry

authors： Cooper LE,O'Leary SE,Begley TP

更新日期：2014-04-15 00:00:00

abstract：:The mechanism of oxidation of a peptide substrate by the flavoprotein lysine-specific demethylase (LSD1) has been examined using the effects of pH and isotopic substitution on steady-state and rapid-reaction kinetic parameters. The substrate contained the 21 N-terminal residues of histone H3, with a dimethylated lysyl...

journal_title：Biochemistry

authors： Gaweska H,Henderson Pozzi M,Schmidt DM,McCafferty DG,Fitzpatrick PF

更新日期：2009-06-16 00:00:00

abstract：:FtmPT1 is a fungal indole prenyltransferase that catalyzes the reaction of tryptophan derivatives with dimethylallyl pyrophosphate to form various biologically active compounds. Herein, we describe detailed studies of FtmPT1 catalysis involving dimethylallyl pyrophosphate and Brevianamide F following the native pathwa...

journal_title：Biochemistry

authors： Pan LL,Yang Y,Merz KM Jr

更新日期：2014-09-30 00:00:00

abstract：:The importance of the evolutionarily conserved Gly-4 residue for the affinity and kinetics of interaction of cystatin A with several cysteine proteinases was assessed by site-directed mutagenesis. Even the smallest replacement, by Ala, resulted in approximately 1000-, approximately 10- and approximately 6000-fold decr...

journal_title：Biochemistry

authors： Estrada S,Nycander M,Hill NJ,Craven CJ,Waltho JP,Björk I

更新日期：1998-05-19 00:00:00

abstract：:Large primary deuterium kinetic isotope effects (1° DKIEs) on enzyme-catalyzed hydride transfer may be observed when the transferred hydride tunnels through the energy barrier. The following 1° DKIEs on kcat/ Km and relative reaction driving force are reported for wild-type and mutant glycerol-3-phosphate dehydrogenas...

journal_title：Biochemistry

authors： Reyes AC,Amyes TL,Richard JP

更新日期：2018-07-24 00:00:00

abstract：:Acireductone dioxygenases (ARDs) are enzymes involved in the methionine recycle pathway, which regulates aspects of the cell cycle. Klebsiella pneumoniae produces two enzymes that share a common polypeptide sequence and differ only in the metal ion present. Reaction of acireductone (1,2-dihydroxy-3-keto-5-methylthiope...

journal_title：Biochemistry

authors： Al-Mjeni F,Ju T,Pochapsky TC,Maroney MJ

更新日期：2002-05-28 00:00:00

abstract：:Integrin beta subunits contain a highly conserved I-like domain that is known to be important for ligand binding. Unlike integrin I domains, the I-like domain requires integrin alpha and beta subunit association for optimal folding. Pactolus is a novel gene product that is highly homologous to integrin beta subunits b...

journal_title：Biochemistry

authors： Takagi J,DeBottis DP,Erickson HP,Springer TA

更新日期：2002-04-02 00:00:00

abstract：:Factor VIII (fVIII) is synthesized as a single chain having a domainal sequence A1-A2-B-A3-C1-C2. Analysis of the proteolyic cleavage of fVIII by thrombin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) identifies three fragments designated fVIIIA1, fVIIIA2, and fVIIIA3-C1-C2 with fragment(s) d...

journal_title：Biochemistry

authors： Lollar P,Parker CG

更新日期：1989-01-24 00:00:00

abstract：:We have studied the tridecadeoxynucleotide CGCGAATTACGCG (I), which contains an additional A at position 9 compared to the dodecanucleotide of which the crystal structure has been determined. Sequence I exhibits no distinct melting curve and also has a concentration-dependent pattern of peaks on reverse-phase chromato...

journal_title：Biochemistry

authors： Roy S,Weinstein S,Borah B,Nickol J,Appella E,Sussman JL,Miller M,Shindo H,Cohen JS

更新日期：1986-11-18 00:00:00

abstract：:Glutamine 143 in human manganese superoxide dismutase (MnSOD) forms a hydrogen bond with the manganese-bound solvent molecule and is investigated by replacement using site-specific mutagenesis. Crystal structures showed that the replacement of Gln 143 with Ala made no significant change in the overall structure of the...

journal_title：Biochemistry

authors： Lévêque VJ,Stroupe ME,Lepock JR,Cabelli DE,Tainer JA,Nick HS,Silverman DN

更新日期：2000-06-20 00:00:00

abstract：:T4 RNA ligase catalyzes the ATP-dependent addition of a single 2'-deoxyribonucleoside 3',5'-bisphosphate to the 3'-hydroxyl of an oligodeoxyribonucleotide. The bisphosphate is joined to the deoxyoligomer by a 3' leads to 5' phosphodiester bond and the product, which is terminated by a 3'-phosphate, is one nucleotide l...

journal_title：Biochemistry

authors： Hinton DM,Baez JA,Gumport RI

更新日期：1978-11-28 00:00:00

abstract：:In the ATP-dependent carboxylation of biotin that is catalyzed by most biotin-dependent carboxylases, a fundamental mechanistic question is whether the ATP activates bicarbonate (via the formation of carboxyphosphate as an intermediate) or whether the ATP activates biotin (via the formation of O-phosphobiotin). We hav...

journal_title：Biochemistry

authors： Ogita T,Knowles JR

更新日期：1988-10-18 00:00:00

abstract：:Several furanocoumarins were tested for their ability to inhibit human P450 2A6 activity. The metabolites and conjugates formed from these furanocoumarins after incubation with reconstituted purified P450 2A6 in the absence and presence of exogenous nucleophiles were characterized by UV and LC/ESI-MS/MS analysis. The ...

journal_title：Biochemistry

authors： Koenigs LL,Trager WF

更新日期：1998-07-14 00:00:00

abstract：:We have de novo designed a heterodimeric coiled-coil formed by two peptides as a capture/delivery system that can be used in applications such as affinity tag purification, immobilization in biosensors, etc. The two strands are designated as K coil (KVSALKE heptad sequence) and E coil (EVSALEK heptad sequence), where ...

journal_title：Biochemistry

authors： De Crescenzo G,Litowski JR,Hodges RS,O'Connor-McCourt MD

更新日期：2003-02-18 00:00:00

abstract：:The N-terminal region of alpha-spectrin is responsible for its association with beta-spectrin in a heterodimer, forming functional tetramers. Non-erythroid alpha-spectrin (alphaII-spectrin) has a significantly higher association affinity for beta-spectrin than the homologous erythroid alpha-spectrin (alphaI-spectrin)....

journal_title：Biochemistry

authors： Li Q,Fung LW

更新日期：2009-01-13 00:00:00

abstract：:The active-site zinc in human glutathione-dependent formaldehyde dehydrogenase (FDH) undergoes coenzyme-induced displacement and transient coordination to a highly conserved glutamate residue (Glu-67) during the catalytic cycle. The role of this transient coordination of the active-site zinc to Glu-67 in the FDH catal...

journal_title：Biochemistry

authors： Sanghani PC,Davis WI,Zhai L,Robinson H

更新日期：2006-04-18 00:00:00

abstract：:Organisms rely on regulation at the molecular level, such as the allosteric regulation of hemoglobin (Hb) function by anions, to meet challenges presented by changing environmental and physiological conditions. A comparison of the effects of anions on oxygenation, oxidation, and sulfhydryl reactivity of Hb leads us to...

journal_title：Biochemistry

authors： Bonaventura C,Tesh S,Faulkner KM,Kraiter D,Crumbliss AL

更新日期：1998-01-13 00:00:00

abstract：:Surface-enhanced resonance Raman scattering (SERRS) spectra were obtained from carotenoids, in the all-trans configuration, located on the antenna complexes of Rhodobacter sphaeroides 2.4.1 membranes. Since resonance Raman (RR) spectra are barely detectable at the concentration that SERRS signals saturate, SERRS repre...

journal_title：Biochemistry

authors： Picorel R,Lu T,Holt RE,Cotton TM,Seibert M

更新日期：1990-01-23 00:00:00

abstract：:Extended illumination slows the rebinding of CO to myoglobin after photodissociation at cryogenic temperatures. Two types of models have been put forward to explain the effect: motions of the CO within the heme pocket or conformational transitions of the protein. To resolve this ambiguity, we have studied the effect o...

journal_title：Biochemistry

authors： Nienhaus GU,Mourant JR,Chu K,Frauenfelder H

更新日期：1994-11-15 00:00:00

abstract：:The aa(3)-type quinol oxidase from Acidianus ambivalens is a divergent member of the heme-copper oxidases superfamily, namely, concerning the putative channels for intraprotein proton conduction. In this study, we used electrochemically induced FTIR difference spectroscopy to identify residues involved in redox-couple...

journal_title：Biochemistry

authors： Hellwig P,Gomes CM,Teixeira M

更新日期：2003-05-27 00:00:00

abstract：:The anaerobic global regulator FNR from Escherichia coli is a [4Fe-4S](2+) cluster-containing dimer that is inactivated by O(2) through disruption of the Fe-S cluster and conversion to the monomeric apoprotein. It was shown that apo-FNR is subject to ClpXP proteolysis, and two recognition sites, amino acids 5-11 and a...

journal_title：Biochemistry

authors： Pan Q,Shan Y,Yan A

更新日期：2012-06-26 00:00:00

abstract：:Kinetics studies of dNTP analogues having pyrophosphate-mimicking β,γ-pCXYp leaving groups with variable X and Y substitution reveal striking differences in the chemical transition-state energy for DNA polymerase β that depend on all aspects of base-pairing configurations, including whether the incoming dNTP is a puri...

journal_title：Biochemistry

authors： Oertell K,Chamberlain BT,Wu Y,Ferri E,Kashemirov BA,Beard WA,Wilson SH,McKenna CE,Goodman MF

更新日期：2014-03-25 00:00:00

abstract：:Experimental measurements of the kinetic mechanism involving isoleucyl-tRNA synthetase proofreading valyl-tRNAIle in Escherichia coli have been incorporated into the conventional Michaelis-Menten model for this system. The model was subjected to a detailed mathematical analysis in the steady state. The results of this...

journal_title：Biochemistry

authors： Okamoto M,Savageau MA

更新日期：1984-04-10 00:00:00

abstract：:R67 dihydrofolate reductase (DHFR), which catalyzes the NADPH dependent reduction of dihydrofolate to tetrahydrofolate, belongs to a type II family of R-plasmid encoded DHFRs that confer resistance to the antibacterial drug trimethoprim. Crystal structure data reveals this enzyme is a homotetramer that possesses a sin...

journal_title：Biochemistry

authors： Hicks SN,Smiley RD,Hamilton JB,Howell EE

更新日期：2003-09-16 00:00:00

abstract：:We have examined the binding of 125I-labeled human and mouse epidermal growth factors (EGF) to human alpha 2-macroglobulin (alpha 2M). In the presence of human neutrophil elastase, both mouse and human EGF bound to alpha 2M, whereas little binding was found to native alpha 2M. Binding was found to be predominantly cov...

journal_title：Biochemistry

authors： Gettins PG,Crews BC

更新日期：1993-08-10 00:00:00

abstract：:The aldehyde oxidoreductase from Desulfovibrio gigas belongs to the family of molybdenum hydroxylases. Besides a molybdenum cofactor which constitutes their active site, these enzymes contain two [2Fe-2S](2+,1+) clusters which are believed to transfer the electrons provided by the substrate to an acceptor which is eit...

journal_title：Biochemistry

authors： More C,Asso M,Roger G,Guigliarelli B,Caldeira J,Moura J,Bertrand P

更新日期：2005-08-30 00:00:00

abstract：:Vitamin K dependent carboxylation of an exogenous peptide substrate and endogenous protein substrates, vitamin K epoxidation, and reduction of vitamin K epoxide were measured in subcellular fractions from rat liver. The rough microsomal fraction was highly enriched in all four activities; lower levels were found in sm...

journal_title：Biochemistry

authors： Carlisle TL,Suttie JW

更新日期：1980-03-18 00:00:00

abstract：:Attempts to alter the guanine specificity of ribonuclease T1 (RNase T1) by rational or random mutagenesis have failed so far. The RNase T1 variant RV (Lys41Glu, Tyr42Phe, Asn43Arg, Tyr45Trp, and Glu46Asn) designed by combination of a random and a rational mutagenesis approach, however, exhibits a stronger preference t...

journal_title：Biochemistry

authors： Czaja R,Struhalla M,Höschler K,Saenger W,Sträter N,Hahn U

更新日期：2004-03-16 00:00:00