Abstract：
:In order to study in detail the generality of the NUX (N = A, U, G, or C; X = A, U, or C) rule for the GUC triplet adjacent to the cleavage site in hammerhead ribozymes, two kinetic parameters, namely, kcat and Km, were determined for substrates with mutations in this triplet, which included double mutants with mutations of both N and X. All substrates with mutated cleavage sites were cleaved with reduced efficiency compared to the wild type. However, some mutations mainly affected kcat and others mainly affected Km, a phenomenon that could not have been predicted from previous results. A as the first or third base increased Km by 35- or 30-fold, respectively, while the effect on kcat was small. U as the first or third base decreased kcat by 8- or 15-fold, respectively, while the effect on Km was small. The effect of C as the first base on kinetic parameters was relatively small. The kinetic parameters of double mutants generally were determined by the effects of both individual point mutations. The AUA triplet gave a very much higher kcat than the other double mutants tested. In general, all of the mutants except for the mutant substrate with the CUC triplet had very low cleavage efficiencies, which ranged from 0.6% to 8% of the wild-type value, as a result of the deleterious effects of the mutations on kcat, Km, or both.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Shimayama T,Nishikawa S,Taira Kdoi
10.1021/bi00011a020subject
Has Abstractpub_date
1995-03-21 00:00:00pages
3649-54issue
11eissn
0006-2960issn
1520-4995journal_volume
34pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:The addition of 10(-9) M insulin to a suspension of rat liver plasma membranes increases the overall lipid microviscosity, eta, by about 10--20%. The effect is confined to physiological concentrations of the hormone and is highly specific. The specificity was demonstrated in experiments where insulin analogues were ad...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00570a009
更新日期：1979-02-06 00:00:00
abstract：:Long-range intraprotein interactions give rise to many important protein behaviors. Understanding how energy is transduced through protein structures to either transmit a signal or elicit conformational changes is therefore a current challenge in structural biology. In an effort to understand such linkages, multiple V...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi060652l
更新日期：2006-06-27 00:00:00
abstract：:DNA polymerase delta from calf thymus has been purified to apparent homogeneity by a new procedure which utilizes hydrophobic interaction chromatography with phenyl-Sepharose at an early step to separate most of the calcium-dependent protease activity from DNA polymerase delta and alpha. The purified enzyme migrates a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00304a003
更新日期：1984-04-24 00:00:00
abstract：:To avoid nonspecific and/or undesirable binding and reactivity of metal ions with cellular components, organisms have evolved metal-specific systems for trafficking proteins. Although systems differ, those handling soft metal ions such as Hg(2+), Cu(+), Zn(2+), etc., all utilize heavy metal-associated (HMA) proteins a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi100537f
更新日期：2010-10-19 00:00:00
abstract：:PII proteins are sensors of alpha-ketoglutarate and adenylylate energy charge that regulate signal transduction proteins, metabolic enzymes, and permeases involved in nitrogen assimilation. Here, purified Escherichia coli PII and two of its receptors, ATase and NRII, were used to study the mechanisms of sensation by P...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9011594
更新日期：2009-12-08 00:00:00
abstract：:Cell-signaling peptides have been extensively used to transport functional molecules across the plasma membrane into living cells. These peptides consist of a hydrophobic sequence and a cationic nuclear localization sequence (NLS). It has been assumed that the hydrophobic region penetrates the hydrophobic lipid bilaye...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi061895g
更新日期：2007-01-30 00:00:00
abstract：:The ability of avian-specific linker histone H5, and the globular domains of H5 (GH5) and H1(0) (GH1(0), to self-associate either free in solution or when bound to DNA was investigated. All three proteins underwent a salt-dependent increase in turbidity that may be indicative of nonspecific interactions. Dithiobis(suc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi980716v
更新日期：1998-09-08 00:00:00
abstract：:Incubation of 3-(2-phenylethyl)-4-methylsydnone (PMS) with liver microsomes from phenobarbital-pretreated rats or with reconstituted cytochrome P-450b results in loss of the enzyme chromophore. Chromophore loss is NADPH-dependent even though the sydnone decomposes by an oxygen- but not enzyme-dependent process to give...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00413a034
更新日期：1988-06-28 00:00:00
abstract：:It has previously been shown that 9S, untransformed progestin, estrogen, androgen, and glucocorticoid receptor complexes in rabbit uterine and liver cytosols contain a 59-kDa protein [Tai, P. K., Maeda, Y., Nakao, K., Wakim, N. G., Duhring, J. L., & Faber, L. E. (1986) Biochemistry 25, 5269-5275]. In this work we show...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00473a021
更新日期：1990-05-29 00:00:00
abstract：:Benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC) are both thiamin diphosphate-dependent enzymes. The two share a common three-dimensional structure and catalyze a similar chemical reaction, i.e., decarboxylation of 2-keto acids. However, they vary significantly in their substrate utilization patter...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9008402
更新日期：2009-09-08 00:00:00
abstract：:Channelrhodopsins (ChRs) from green flagellate algae function as light-gated ion channels when expressed heterologously in mammalian cells. Considerable interest has focused on understanding the molecular mechanisms of ChRs to bioengineer their properties for specific optogenetic applications such as elucidating the f...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi501243y
更新日期：2015-01-20 00:00:00
abstract：:12-Iodo-cis-9-octadecenoic acid (12-IODE) is a time-dependent, irreversible inactivator of soybean lipoxygenase 1. The rate of inactivation is independent of 12-IODE concentration above 20 microM and is half-maximal at about 4 microM. Inactivation by 12-IODE requires lipid hydroperoxide, which must be present even aft...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00424a019
更新日期：1988-11-29 00:00:00
abstract：:The crystal structure of Pseudomonas putida cytochrome P-450cam in the substrate-free form has been refined at 2.20-A resolution and compared to the substrate-bound form of the enzyme. In the absence of the substrate camphor, the P-450cam heme iron atom is hexacoordinate with the sulfur atom of Cys-357 providing one a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00366a049
更新日期：1986-09-09 00:00:00
abstract：:Vinca site agents are antimicrotubule compounds that bind to the same site on tubulin as do the vinca alkaloids. These include agents that induce the formation of nonmicrotubule oligomers of tubulin (vinblastine and vincristine) and agents that do not (maytansine and rhizoxin). All of these quench the fluorescence of ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00021a012
更新日期：1995-05-30 00:00:00
abstract：:1H NMR and ligand-binding data were used to assess the role of residue Arg(E10) in ligand stabilization of several site-directed mutants, all carrying the His(E7) to Val substitution, obtained using a synthetic sperm whale myoglobin gene. Arg(E10) was previously found to form a hydrogen bond with the ligand in fluoro-...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00074a015
更新日期：1993-06-15 00:00:00
abstract：:Biochemical properties of a detergent-solubilized tetrodotoxin binding component from Electrophorus electricus have been examined and compared with those found for the membrane-bound protein. The toxin binding component was solubilized with high efficiency by a variety of nonionic detergents and with lower efficiency ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00267a029
更新日期：1982-11-23 00:00:00
abstract：:Sialyltransferase activities, SAT-3 (CMP-NeuAc:nLcOse4Cer alpha 2-3sialyltransferase) and SAT-4 (CMP-NeuAc:GgOse4Cer alpha 2-3sialyltransferase), in Colo 205 cells catalyze the transfer of sialic acid to the terminal galactose of GlcNc-- and GalNAc-containing glycolipid substrates, respectively. Competition kinetic st...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi960239l
更新日期：1996-04-23 00:00:00
abstract：:Blood coagulation is initiated by Ca(2+)-dependent binding of coagulation factor VIIa (FVIIa) to its cofactor, tissue factor (TF). The TF:FVIIa complex activates factors IX and X, ultimately leading to the formation of thrombin and the coagulation of blood. FVII consists of an N-terminal gamma-carboxyglutamic-acid-con...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi980522f
更新日期：1998-07-28 00:00:00
abstract：:Miniproteins reduce the complexity of the protein-folding problem allowing systematic studies of contributions to protein folding and stabilization. Here, we describe the rational redesign of a miniprotein, PPα, comprising a polyproline II helix, a loop, and an α helix. The redesign provides a de novo framework for in...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.9b00067
更新日期：2019-07-16 00:00:00
abstract：:Kinetic study of a series of compounds containing the thrombin-directed peptide D-Phe-ProboroArg-OH had indicated that the structure of the N-terminal blocking group may be correlated with binding [Kettner, C., Mersinger, L., & Knabb, R. (1990) J. Biol. Chem. 265, 18289-18297]. In order to further study this phenomeno...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi952164b
更新日期：1996-07-30 00:00:00
abstract：:Theory for enzyme-catalyzed reactions is developed for the dependence on product concentration of deuterium isotope effects on V and V/K. Generally, a product that decreases the off-rate for a second product to zero causes the isotope effect on V/K to decrease to DKeq and that on V to decrease to a value between 1 and...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00058a013
更新日期：1993-02-23 00:00:00
abstract：:A stereochemical analysis has been carried out on two vinylpyruvate hydratases (VPH), which convert 2-hydroxy-2,4-pentadienoate to 2-keto-4S-hydroxypentanoate in meta-fission pathways. Bacterial strains with this pathway can use aromatic compounds as sole sources of energy and carbon. The analysis was carried out usin...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.6b00552
更新日期：2016-07-26 00:00:00
abstract：:The ras oncogene products (H-Ras, K-Ras, and N-Ras) have been regarded as some of the most promising targets for anticancer drug discovery because their activating mutations are frequently found in human cancers. Nonetheless, molecular targeted therapy for them is currently unavailable. Here, we report the discovery o...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.8b00680
更新日期：2018-09-11 00:00:00
abstract：:The chicken and goose egg white lysozymes (ChEWL and GoEWL) are homologues, but differ in substrate specificity. ChEWL catalyzes the hydrolysis of the glycosidic bonds of bacterial peptidoglycans and chitin-derived substrates, while GoEWL is specific for bacterial peptidoglycans. The active-site aspartate 52 residue o...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi951671q
更新日期：1996-02-13 00:00:00
abstract：:Acyl-CoA:cholesterol O-acyltransferase (EC 2.3.1.26) (ACAT) catalyzes the intracellular synthesis of cholesteryl esters from cholesterol and fatty acyl-CoA at neutral pH. Despite the probable pathophysiologic role of ACAT in vascular cholesteryl ester accumulation during atherogenesis, its mechanism of action and its ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00419a025
更新日期：1988-09-20 00:00:00
abstract：:In search of the regulation mechanisms for isoform specific myosin assembly, we have used the COOH-terminal fragments of nonmuscle myosin isoforms MIIA and MIIB (MIIA(F46) and MIIB(alpha)(F47)) as a model system. Phosphorylation by protein kinase C (PK C) or casein kinase II (CK II) within or near the nonhelical tail-...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi000347e
更新日期：2000-09-19 00:00:00
abstract：:When alpha,beta-unsaturated substrates bind to the active site of enoyl-CoA hydratase, large spectral changes can be observed [D'Ordine, R. L., et al. (1994) Biochemistry 33, 12635-12643]. The differences in the isotropic magnetic shieldings of the free and active site-bound forms of the carbonyl, alpha-, and beta-car...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi015845h
更新日期：2002-02-26 00:00:00
abstract：:The role of the C-domain sites of cardiac troponin C in the modulation of the calcium signal remains unclear. In this study, we investigated the effects of hypertrophic cardiomyopathy-linked mutations A8V, E134D, and D145E in cardiac troponin C on the properties of the C-domain sites. The A8V mutation had essentially ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi100400h
更新日期：2010-06-15 00:00:00
abstract：:Recently, we synthesized the first individual β,γ-CHX-dGTP diastereomers [(R)- or (S)-CHX, where X is F or Cl] and determined their structures in ternary complexes with DNA polymerase β (pol β). We now report stereospecificity by pol β on the mixed β,γ-CHX diastereomer pairs using nuclear magnetic resonance and on the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi3010335
更新日期：2012-10-30 00:00:00
abstract：:Raman spectra of phycocyanobilin, phycocyanin, and allophycocyanin were obtained at resonance with their visible and near-UV transitions. These spectra were empirically assigned with the help of 14N- and 15N-isotopic substitutions and comparisons with resonance Raman spectra of phycoerythrin. These results confirm the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00205a019
更新日期：1994-10-04 00:00:00
