Abstract:
:In the Arc repressor dimer, the side chains of Ile37 and Val41 in alpha-helix B pack against each other and against the symmetry-related side chains of Ile37' and Val41' in alpha-helix B' to form part of the hydrophobic core and the dimer interface. Following combinatorial mutagenesis of these positions, only the wild-type combination of hydrophobic residues was recovered as a fully active protein, and only a few conservative replacements were recovered as stably folded or partially active proteins. Equilibrium and kinetic studies of the folding of purified mutants show that the delta-CH3 groups of Ile37 and Ile37' contribute approximately 2 kcal/mol of dimer to protein stability and are involved in interactions that are only partially formed in the transition state for protein folding. Alanine substitution at either position 37 or 41 results in proteins which differ from wild type in being monomeric at a concentration of 10 microM, having reduced secondary structure, having solvent-exposed tryptophans, and showing non-cooperative thermal and urea denaturation transitions. These mutants appear to exist in a physiologically denatured state that is similar in many ways to the molten globule state.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Milla ME,Sauer RTdoi
10.1021/bi00010a025subject
Has Abstractpub_date
1995-03-14 00:00:00pages
3344-51issue
10eissn
0006-2960issn
1520-4995journal_volume
34pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Heme oxygenase-1 (HO-1) is an enzyme that catalyzes the oxidative degradation of heme. Since free heme is toxic to cells, rapid degradation of heme is important for maintaining cellular health. There have been useful mechanistic studies of the HO reaction based on crystal structures; however, how HO-1 recognizes heme ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi5009694
更新日期:2015-01-20 00:00:00
abstract::Neisseria meningitidis α-1,4-galactosyltransferase C (LgtC) is responsible for the transfer of α-galactose from donor UDP-galactose to the lipooligosaccharide terminal acceptor lactose. Crystal structures of its substrate analogue complexes have provided key insights into the galactosyl transfer mechanism, including a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi301317d
更新日期:2013-01-15 00:00:00
abstract::Myocardial contraction is initiated when Ca2+ binds to site II of cardiac troponin C. This 12-residue EF-hand loop (NH2-DEDGSGTVDFDE-COOH) contains six residues (bold) that coordinate Ca2+ binding and six residues that do not appear to influence Ca2+ binding directly. We have introduced six single-cysteine substitutio...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi800164c
更新日期:2008-05-06 00:00:00
abstract::The inhibitory effect of phosphorothioate residues, located within one strand of double-stranded DNA, on the hydrolytic activity of the restriction endonuclease EcoRV was investigated. Specific incorporation of a phosphorothioate group at the site of cleavage yielded the sequence 5'-GATsATC-3'. This modified sequence ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00493a008
更新日期:1990-10-16 00:00:00
abstract::Terreic acid is a metabolite with antibiotic properties produced by the fungus Aspergillus terreus. We found that terreic acid is a covalent inhibitor of the bacterial cell wall biosynthetic enzyme MurA from Enterobacter cloacae and Escherichia coli in vitro. The crystal structure of the MurA dead-end complex with ter...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100365b
更新日期:2010-05-18 00:00:00
abstract::Cerebrovascular deposition of fibrillar 39-42 amino acid amyloid beta-protein (Abeta), a condition known as cerebral amyloid angiopathy (CAA), is a key pathological feature of Alzheimer's disease and related disorders including hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D). Severe cases of CAA, ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0002840
更新日期:2000-06-27 00:00:00
abstract::Three methods, fluorescence anisotropy of rhodamine-labeled profilin, intrinsic fluorescence and nucleotide exchange, give the same affinity, Kd = 0.1 microM, for Acanthamoeba profilins binding amoeba actin monomers with bound Mg-ATP. Replacement of serine 38 with cysteine created a unique site where labeling with rho...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980093l
更新日期:1998-08-04 00:00:00
abstract::Bleeding, the most serious complication of thrombolytic therapy with tissue-type plasminogen activator (t-PA), is thought to result from lysis of fibrin in hemostatic plugs and from the systemic lytic state caused by unopposed plasmin. One mechanism by which systemic plasmin can impair hemostasis is by partially degra...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0525730
更新日期:2006-04-04 00:00:00
abstract::The binding of Ca2+ and the resulting change in catalytic specificity that allows phosphorylation of the calcium ATPase of sarcoplasmic reticulum by ATP were examined by measuring the amount of phosphoenzyme formation from [32P]ATP, or 45Ca incorporation into vesicles, after the simultaneous addition of ATP and EGTA a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00423a018
更新日期:1988-11-15 00:00:00
abstract::Neuroligins 1-4 are postsynaptic transmembrane proteins capable of initiating presynaptic maturation via interactions with beta-neurexin. Both neuroligins and beta-neurexins have alternatively spliced inserts in their extracellular domains. Using analytical ultracentrifugation, we determined that the extracellular dom...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0614131
更新日期:2006-10-24 00:00:00
abstract::Upon cleavage of the reactive thioester bonds (Cys-949-Glx-952) of tetrameric human alpha 2-macroglobulin (alpha 2M) by methylamine, one sulfhydryl group per alpha 2M subunit is exposed. These identical sulfhydryl group sites were labeled with the thiol-specific nitroxide spin-labels (1-oxy-2,2,5,5-tetramethyl-3-pyrro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00414a053
更新日期:1988-07-12 00:00:00
abstract::By limited proteolysis of a type kappa immunoglobulin light chain (Oku) with clostripain, both the VL and CL fragments were obtained with a high yield. The unfolding and refolding by guanidine hydrochloride of light chain Oku and its VL and CL fragments were studied at pH 7.5 and 25 degrees C with circular dichroism a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00393a015
更新日期:1987-09-22 00:00:00
abstract::Adenosine A(2B) receptors, which play a role in inflammation and cancer, are of considerable interest as novel drug targets. To gain deeper insights into ligand binding and receptor activation, we exchanged amino acids predicted to be close to the binding pocket. The alanine mutants were stably expressed in CHO cells ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi3012065
更新日期:2013-01-29 00:00:00
abstract::Enterokinase has been isolated from the contents of bovine duodena and purified 1200-fold in 41% yield. The isolation procedure employed DEAE chromatography, affinity chromatography on immobilized p-aminobenzamidine, and gel filtration. The resultant pure enzyme exhibits a single band on sodium dodecyl sulfate gel ele...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00634a011
更新日期:1977-07-26 00:00:00
abstract::Five previously unknown hemorrhagic proteins, designated hemorrhagic toxins a,b,c,d, and e, were isolated from the venom of the western diamondback rattlesnake (Crotalus atrox). Molecular weights of hemorrhagic toxins a-e were determined to be 68 000, 24 000, 24 000, 24 000, and 25 700, respectively, by sodium dodecyl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00609a033
更新日期:1978-08-08 00:00:00
abstract::The enzyme phosphoenolpyruvate carboxykinase (PEPCK) catalyzes the reversible conversion of oxalacetate and GTP to phosphoenolpyruvate (PEP), GDP, and CO2. PEPCK from higher organisms is a monomer, specifically requires GTP or ITP, and uses Mn2+ as the activating cation. Currently, there is no crystal structure of GTP...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011374n
更新日期:2001-09-18 00:00:00
abstract::We find that the photocycle of halorhodopsin (HR) in the presence of nitrate (but not chloride) consists of two parallel series of reactions. The first is essentially the same as that which occurs in the presence of chloride: HRhv----HRK----HRKL----HRL----HRO----HR. The second photocycle, however, which we describe as...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00438a039
更新日期:1989-06-13 00:00:00
abstract::The binding of Lens culinaris lectin to the receptors of rabbit erythrocytes was studied by a quantitative fluorometric method using the fluoresceinated conjugate. Equilibrium data showed the presence of 1.2 x 10(6) receptors/cell with an association constant varying from 8 to 3 x 10(6) M-1 over a temperature range of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00616a022
更新日期:1978-11-14 00:00:00
abstract::A cyclic nucleotide phosphodiesterase was extensively purified from the 100000g supernatant fraction of human platelets. The purification was 2500-3000-fold with 30% recovery of activity. The enzyme was isolated by DEAE-cellulose chromatography followed by adsorption to blue dextran-Sepharose and elution with cAMP. Th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00303a034
更新日期:1984-04-10 00:00:00
abstract::IHF and HU are small basic proteins of eubacteria that bind as homodimers to double-stranded DNA and bend the duplex to promote architectures required for gene regulation. These architectural proteins share a common alpha/beta fold but exhibit different nucleic acid binding surfaces and distinct functional roles. With...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7009426
更新日期:2008-03-25 00:00:00
abstract::The conformation and activity of three different lipases have been studied in reverse micelles formed by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in isooctane. In the case of human pancreatic lipase, the conformation of the polypeptide chain--as judged from far-UV circular dichroism measurements--is only slightly...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00066a025
更新日期:1993-04-20 00:00:00
abstract::The initial hydrolysis of CaATP by chloroplast coupling factor 1 was studied with the quenched-flow method. The time course of hydrolysis can be described as a first-order conversion of the enzyme to an active form followed by steady-state formation of product. The rat constant for the first-order process is independe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00382a035
更新日期:1987-04-21 00:00:00
abstract::Kinases play a critical role in cellular signaling and are dysregulated in a number of diseases, such as cancer, diabetes, and neurodegeneration. Therapeutics targeting kinases currently account for roughly 50% of cancer drug discovery efforts. The ability to explore human kinase biochemistry and biophysics in the lab...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b01081
更新日期:2018-08-07 00:00:00
abstract::Calf brain tubulin was subjected to isoelectric focusing and tryptic peptide map analysis. Results from isoelectric focusing experiments showed a total number of 17 well-resolved protein peaks. The number of peaks and the mass distribution under each peak remained the same when the concentration of protein or ampholyt...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00512a006
更新日期:1981-04-28 00:00:00
abstract::The highly cooperative binding of fd gene 5 to single-stranded DNA was studied kinetically by rapid photo-cross-linking and stopped-flow UV absorption measurements. The observed change in absorbance was shown to be due to the binding by direct evidence of rapid photo-cross-linking of the bound proteins to fd DNA. The ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00294a028
更新日期:1983-12-06 00:00:00
abstract::A highly active, large-scale preparation of ubiquinol:cytochrome c2 oxidoreductase (EC 1.10.2.2; cytochrome bc1 complex) has been obtained from Rhodobacter sphaeroides. The enzyme was solubilized from chromatophores by using dodecyl maltoside in the presence of glycerol and was purified by anion-exchange and gel filtr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00463a004
更新日期:1990-03-20 00:00:00
abstract::Inefficient maturation and trafficking to the cell surface of the cystic fibrosis transmembrane conductance regulator (CFTR) is the primary cause of cystic fibrosis. CFTR protein that fails to mature accumulates as an immature core-glycosylated protein and is rapidly degraded. To determine how the structures of mature...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992620m
更新日期:2000-04-04 00:00:00
abstract::To investigate a conformational change accompanying peptide binding to class II MHC proteins, we probed the structure of a soluble version of the human class II MHC protein HLA-DR1 in empty and peptide-loaded forms. Peptide binding induced a large decrease in the effective radius of the protein as determined by gel fi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi983048m
更新日期:1999-05-04 00:00:00
abstract::Oligonucleotide-directed triple helix formation provides an elegant rational basis for gene-specific DNA targeting and has been widely used to interfere with gene expression ("antigene" strategies) and as a molecular tool for biological studies. Various strategies have been developed to introduce sequence modification...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001605a
更新日期:2001-02-13 00:00:00
abstract::The flavocytochrome p-cresol methylhydroxylase from Pseudomonas putida has been reported to have a Mr of 114,000 and to consist of two subunits, a flavoprotein and a cytochrome c, each with a Mr of 58,000. Recent X-ray crystallographic data from our laboratories [Shamala, N., Lim, L. W., Mathews, F. S., McIntire, W., ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00368a021
更新日期:1986-10-07 00:00:00