Abstract:
:The effects of ions on the interaction of lac repressor protein and operator DNA have been studied by the membrane filter technique. The equilibrium association constant was determined as a function of monovalent and divalent cation concentrations, anions, and pH. The binding of repressor and operator is extremely sensitive to the ionic environment. The dependence of the observed equilibrium constant on salt concentration is analyzed according to the binding theory of Record et al. [Record, M. T., Jr., Lohman, T. M., & deHaseth, P. L. (1976) J. Mol. Biol. 107, 145]. The number of ionic interactions in repressor--operator complex is deduced from the slopes of the linear log-log plots. About 11 ionic interactions are formed between repressor and DNA phosphates at pH 7.4 and about 9 ionic interactions at pH 8.0, in reasonable agreement with previous estimates. A favorable nonelectrostatic binding free energy of about 9-12 kcal/mol is estimated from the extrapolated equilibrium constants at the 1 M standard state. The values are in good accord with recent results for the salt-independent binding of repressor core and operator DNA. The effects of pH on the repressor--operator interaction are small, and probably result from titration of functional groups in the DNA-binding site of the protein. For monovalent salts, the equilibrium constant is slightly dependent on cation type and highly dependent on anion type. At constant salt concentration, the equilibrium constant decreases about 10000-fold in the order CH3CO2- greater than or equal to F- greater than Cl- greater than Br- greater than NO3- greater than SCN- greater than I-. The wide range of accessible equilibrium constants provides a useful tool for in vitro studies of the repressor--operator interaction.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Barkley MD,Lewis PA,Sullivan GEdoi
10.1021/bi00516a027subject
Has Abstractpub_date
1981-06-23 00:00:00pages
3842-51issue
13eissn
0006-2960issn
1520-4995journal_volume
20pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Pig pancreatic alpha-amylase (PPA), an enzyme belonging to the alpha-amylase family, is involved in the degradation of starch. Like some other members of this family, PPA requires chloride to reach maximum activity levels. To further explain the mechanism of chloride activation, a crystal of wild-type PPA soaked with ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi048201t
更新日期:2005-03-08 00:00:00
abstract::Compartmentation and NMR visibility of mitochondrial adenine nucleotides were quantitated in isolated rat liver mitochondria respiring on succinate and glutamate in vitro at 8 and 25 degrees C. Intra- and extramitochondrial nucleotides were discriminated by adding the chelator trans-1,2-diaminocyclohexane-N,N,N',N'-te...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00436a030
更新日期:1989-05-16 00:00:00
abstract::The Haemophilus influenzae diaminopimelate epimerase was cloned, expressed, purified, and crystallized in the C2221 space group (a = 102.1 A, b = 115.4 A, c = 66.3 A, alpha = beta = gamma = 90 degrees). The three-dimensional structure was solved to 2.7 A using a single Pt derivative and the Se-Met-substituted enzyme t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982138o
更新日期:1998-11-24 00:00:00
abstract::MerR, the metalloregulator of the mercury resistance (mer) operon, binds the operator (merO)between -10 and -35 of the merTPCAD promoter (PT) and sequesters RNA polymerase (RNAP) in a closed complex. MerR represses PT until Hg(II) induces it to underwind merO DNA and thus facilitate open complex formation. We used cro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982814m
更新日期:1999-03-16 00:00:00
abstract::The orphan receptor short heterodimer partner (SHP) is a common partner for a great number of nuclear receptors, and it plays an important role in many diverse physiological events. In a previous study, we described SHP as a strong repressor of the androgen receptor (AR). Herein, we addressed the mechanism of action o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi047308d
更新日期:2005-04-26 00:00:00
abstract::Fourteen oligonucleotides 8-21 nucleotides in length and their complements were synthesized as DNA and RNA. For each sequence, four kinds of duplexes, DNA:DNA, RNA:RNA, DNA:RNA, and RNA:DNA, were prepared. Twelve sequences had A.T/U content varying from 25 to 80% and dPy content in the DNA strands varying from 0 to 10...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00034a013
更新日期:1995-08-29 00:00:00
abstract::The major plasma membrane protein of human erythrocytes is the anion transport protein, termed protein 3. We previously reported a variant form of protein 3 that is elongated on the amino-terminal end of the molecule, which is exposed on the cytoplasmic side of the membrane, but otherwise its features are identical wi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00334a003
更新日期:1985-06-18 00:00:00
abstract::Chloroperoxidase is a versatile fungal heme-thiolate protein that catalyzes a variety of one-electron and two-electron oxidations. We report here that the alkylation of an essential histidine residue showed no effect on the one-electron peroxidations but inhibited two-electron oxidations. The pH profiles of different ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7022656
更新日期:2008-03-04 00:00:00
abstract::Temporins are short (10-13 amino acids) and linear antimicrobial peptides first isolated from the skin of the European red frog, Rana temporaria, and are effective against Gram-positive bacteria and Candida albicans. To get insight into their mechanism(s) of action, we compared the effects on model membranes exerted b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011929e
更新日期:2002-04-02 00:00:00
abstract::Protein electrochemistry in an ultra-thin-layer electrochemical cell suitable for UV/vis and IR spectroscopy has been used to characterize the vibrational modes of the primary electron donors of Rhodobacter sphaeroides and Rhodopseudomonas viridis reaction centers in their neutral and cation radical states (P and P+, ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00068a007
更新日期:1993-05-04 00:00:00
abstract::Rat liver sinusoidal endothelial cells (LECs) mediate the removal of hyaluronan (HA) from the circulation via a specific Ca(2+)-independent endocytic receptor. To characterize the receptor biochemically, detergent-soluble extracts were prepared from crude LEC membranes. Using a dot blot assay to quantitate 125I-HA bin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00117a039
更新日期:1992-01-21 00:00:00
abstract::The ratio of the second-order rate constants for reduction of dihydroxyacetone phosphate (DHAP) and of the neutral truncated substrate glycolaldehyde (GLY) by glycerol 3-phosphate dehydrogenase (NAD (+), GPDH) saturated with NADH is (1.0 x 10 (6) M (-1) s (-1))/(8.7 x 10 (-3) M (-1) s (-1)) = 1.1 x 10 (8), which was u...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi8001743
更新日期:2008-04-22 00:00:00
abstract::Class I major histocompatibility complex (MHC) proteins present peptide antigens to T cells during the immune response against viruses. Peptides are loaded into newly synthesized class I heterodimers in the endoplasmic reticulum such that most or all cell surface class I molecules contain peptides derived from endogen...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00192a020
更新日期:1994-07-05 00:00:00
abstract::Starting from a standard unfolded state (3.0 M guanidine hydrochloride, pH 7.2), the kinetics of refolding of iso-2-cytochrome c have been investigated as a function of final pH between pH 3 and pH 10. Absorbance in the ultraviolet and visible spectral regions and tryptophan fluorescence are used to monitor folding. O...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00419a020
更新日期:1988-09-20 00:00:00
abstract::The binding of various forms of vanadate to myosin and myosin subfragment 1 (S-1) was studied by 51V NMR at increasing vanadate concentrations between 0.06 and 1.0 mM. The distribution of the various forms of vanadate in the solution depended on the total concentration of vanadate. At low concentrations, the predomina...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00490a029
更新日期:1990-09-25 00:00:00
abstract::An organic solvent soluble polypeptide has been isolated from photoreceptor complexes and chromatophores of Rhodospirillum rubrum. After extraction of the protein from lyophilized samples with 1:1 chloroform-methanol, it was purified by column chromatography. Its isoelectric point determined by isoelectric focusing wa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00624a011
更新日期:1977-03-08 00:00:00
abstract::The kinetics of tert-butyl isocyanide binding to the heme protein horseradish peroxidase (HRP) at 22 degrees C was examined on all time scales, from minutes to picoseconds, in aqueous borate buffer at pH 9.08. Unlike myoglobin (Mb) or hemoglobin, HRP shows two bimolecular ligand binding processes. For comparison, bind...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9518149
更新日期:1996-02-06 00:00:00
abstract::The mechanism of N-methyltryptophan oxidase, a flavin-dependent amine oxidase from Escherichia coli, was studied using a combination of kinetic isotope effects and theoretical calculations. The 15(kcat/Km) kinetic isotope effect for sarcosine oxidation is pH-dependent with a limiting value of 0.994-0.995 at high pH. D...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700482h
更新日期:2007-06-26 00:00:00
abstract::Human type-alpha transforming growth factor (hTGF alpha) is a small mitogenic protein containing 50 amino acids and three disulfide bonds. It has both sequence and structural homology with epidermal growth factor (EGF). While the three-dimensional structures of hTGF alpha and other EGF-like proteins have been studied ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00008a003
更新日期:1995-02-28 00:00:00
abstract::Triple helix-forming oligonucleotides (TFOs) bind with high affinity and specificity to homopurine-homopyrimidine sequences in DNA and have been shown to inhibit transcription of target genes in various experimental systems. In the present study, we evaluated the ability of 3'-amino-modified phosphodiester TFOs direct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992185w
更新日期:2000-05-02 00:00:00
abstract::The self-association reaction in which four melittin molecules associate to form an aqueously soluble tetramer was studied by fluorescent spectroscopy. At 23 degrees C, pH 7.15, gamma/2 0.50, the dissociation constant, Kd, is 3.20 x 10(-16) M3. At 23 degrees C, gamma/2 0.60, melittin has an amino acyl group with a pro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00272a026
更新日期:1983-02-01 00:00:00
abstract::The FAD-dependent alpha-glycerophosphate oxidase (GlpO) from Enterococcus casseliflavus and Streptococcus sp. was originally studied as a soluble flavoprotein oxidase; surprisingly, the GlpO sequence is 30-43% identical to those of the alpha-glycerophosphate dehydrogenases (GlpDs) from mitochondrial and bacterial sour...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701685u
更新日期:2008-01-22 00:00:00
abstract::Halorhodopsin from Natronomonas pharaonis (NpHR) acts an inward-directed, light-driven chloride pump and forms a homotrimer. To evaluate effect of trimeric assembly, that is, intermolecular interaction, on the control or modulation of light-driven chloride pumping activity of individual HRs, it is important to underst...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901380c
更新日期:2009-12-29 00:00:00
abstract::Cyanobactin heterocyclases share the same catalytic domain (YcaO) as heterocyclases/cyclodehydratases from other ribosomal peptide (RiPPs) biosynthetic pathways. These enzymes process multiple residues (Cys/Thr/Ser) within the same substrate. The processing of cysteine residues proceeds with a known order. We show the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b00084
更新日期:2019-04-23 00:00:00
abstract::Ryanodine receptor (RyR) mutations linked with some congenital skeletal and cardiac diseases are localized to three easily definable regions: region 1 (N-terminal domain), region 2 (central domain), and a rather broad region 3 containing the channel pore. As shown in our recent studies, the interdomain interaction bet...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi061557f
更新日期:2007-04-10 00:00:00
abstract::The electronic (ultraviolet) circular dichroism (UVCD) and vibrational circular dichroism (VCD) of 20 proteins are systematically compared as to their relationship to the secondary structures of these proteins. The UVCD spectra are statistically treated by use of the same factor analysis methods used previously for VC...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00242a012
更新日期:1991-07-16 00:00:00
abstract::Transfection of cos-1 cells with either prostaglandin endoperoxide H synthase-1 (PGHS-1) or -2 (PGHS-2) results in a mixed population of cells containing a diverse range of expressed enzyme. The use of fluorescent substrates and antibodies, in conjunction with fluorescence microscopy, provides the means to quantitate ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00021a034
更新日期:1995-05-30 00:00:00
abstract::We developed a general strategy for labeling expressed membrane proteins with a peptide epitope tag and detecting the tagged proteins in native cellular membranes. First, we genetically encoded the unnatural amino acid p-azido-L-phenylalanine (azF) at various specific sites in a G protein-coupled receptor (GPCR), C-C ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi301292h
更新日期:2013-02-12 00:00:00
abstract::From the larger set of 191 variants at all the variable contact positions in the turkey ovomucoid third domain, we selected a subset that consists of Asp, Glu, His, and Lys residues at eight of the nine contiguous P6-P3' positions (residues 13-21), the exception being P3-Cys16 which is involved in a conserved disulfid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0269512
更新日期:2003-03-18 00:00:00
abstract::Mouse photoreceptor function and survival critically depend on Ca(2+)-regulated retinal membrane guanylyl cyclase (RetGC), comprised of two isozymes, RetGC1 and RetGC2. We characterized the content, catalytic constants, and regulation of native RetGC1 and RetGC2 isozymes using mice lacking guanylyl cyclase activating ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200491b
更新日期:2011-06-28 00:00:00