Abstract:
:The kinetics of the slow folding and unfolding reactions of barstar, a bacterial ribonuclease inhibitor protein, have been studied at 23(+/-1) degrees C, pH 8, by the use of tryptophan fluorescence, far-UV circular dichroism (CD), near-UV CD, and transient mixing (1)H nuclear magnetic resonance (NMR) spectroscopic measurements in the 0-4 M range of guanidine hydrochloride (GdnHCl) concentration. The denaturant dependences of the rates of folding and unfolding processes, and of the initial and final values of optical signals associated with these kinetic processes, have been determined for each of the four probes of measurement. Values determined for rates as well as amplitudes are shown to be very much probe dependent. Significant differences in the intensities and rates of appearance and disappearance of several resolved resonances in the real-time one-dimensional NMR spectra have been noted. The NMR spectra also show increasing dispersion of chemical shifts during the slow phase of refolding. The denaturant dependences of rates display characteristic folding chevrons with distinct rollovers under strongly native as well as strongly unfolding conditions. Analyses of the data and comparison of the results obtained with different probes of measurement appear to indicate the accumulation of a myriad of intermediates on parallel folding and unfolding pathways, and suggest the existence of an ensemble of transition states. The energetic stabilities of the intermediates estimated from kinetic data suggest that they are approximately half as stable as the fully folded protein. The slowness of the folding and unfolding processes (tau = 10-333 s) and values of 20.5 (+/-1.4) and 18 (+/-0.5) kcal mol(-)(1) for the activation energies of the slow refolding and unfolding reactions suggest that proline isomerization is involved in these reactions, and that the intermediates accumulate and are therefore detectable because the slow proline isomerization reaction serves as a kinetic trap during folding.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Bhuyan AK,Udgaonkar JBdoi
10.1021/bi990285wsubject
Has Abstractpub_date
1999-07-13 00:00:00pages
9158-68issue
28eissn
0006-2960issn
1520-4995pii
bi990285wjournal_volume
38pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Escherichia coli dihydrofolate reductase contains five tryptophan residues that are spatially distributed throughout the protein and located in different secondary structural elements. When these tryptophans are replaced with [6-19F]tryptophan, distinct native and unfolded resonances can be resolved in the 1-D 19F NMR...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971962u
更新日期:1998-01-06 00:00:00
abstract::The metal-dependent deacetylase LpxC catalyzes the first committed step of lipid A biosynthesis in Gram-negative bacteria. Accordingly, LpxC is an attractive target for the development of inhibitors that may serve as potential new antibiotics for the treatment of Gram-negative bacterial infections. Here, we report the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060823m
更新日期:2006-07-04 00:00:00
abstract::2,3-Butanedione monoxime (BDM) reversibly inhibits force production in muscle. At least part of its action appears to be directly on the contractile apparatus. To understand better its mechanism of action, we studied the effect of BDM on the steps of myosin subfragment 1 Mg(2+)-ATPase in 0.1 M potassium acetate, pH 7....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00163a036
更新日期:1992-12-08 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::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
pub_type: 杂志文章
doi:10.1021/bi500281a
更新日期:2014-04-15 00:00:00
abstract::Histone deacetylases have proven to be attractive novel targets for the treatment of cancer. The first inhibitor of histone deacetylases was approved for the treatment of cutaneous T-cell lymphoma in 2006. The identification of new lead structures with improved effectiveness and fewer side effects is necessary. This r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901617w
更新日期:2010-02-23 00:00:00
abstract::Structure-function studies of antibody-antigen systems include the identification of amino acid residues in the antigen that interact with an antibody and elucidation of their individual contributions to binding affinity. We used fluorescence correlation spectroscopy (FCS) and alanine-scanning mutagenesis to character...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0607047
更新日期:2006-11-28 00:00:00
abstract::The size and surface curvature dependence of the properties and stability of single lamellar vesicles have been investigated by using a variety of physicochemical techniques. Dipalmitoylphosphatidylcholine single lamellar vesicles of sizes ranging between 200 and 900 A in diameter have been prepared by the French pres...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00515a024
更新日期:1981-06-09 00:00:00
abstract::Aromatic amine dehydrogenase (AADH) is the second enzyme known to possess the tryptophan tryptophylquinone (TTQ) prosthetic group. Its ability to catalyze the oxidative deamination of a wide range of aromatic and aliphatic amines has been investigated. Steady-state and transient kinetic studies of the reaction of AADH...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00003a015
更新日期:1995-01-24 00:00:00
abstract::The nuclear tRNA 3' processing activity from wheat has been characterized and partially purified. Several characteristics of the wheat nuclear 3' processing enzyme now allow this activity to be distinguished from its mitochondrial counterpart. The nuclear enzyme is an endonuclease, which we termed nuclear RNase Z. The...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992253e
更新日期:2000-02-29 00:00:00
abstract::All CG dinucleotides along exons 5-8 of the p53 tumor suppressor gene contain endogenous 5-methylcytosine (MeC). These same sites (e.g., codons 157, 158, 245, 248, and 273) are mutational hot spots in smoking-induced lung cancer. Several groups used the UvrABC endonuclease incision assay to demonstrate that methylated...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035259j
更新日期:2004-01-20 00:00:00
abstract::ncd is a kinesin-related motor protein from Drosophila that moves in the opposite direction along microtubules to kinesin. To learn more about the ncd mechanism, ncd motor domain (R335-K700) was expressed in Escherichia coli and its enzymatic characteristics were studied. The ncd motor domain was purified from the cel...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00040a042
更新日期:1995-10-10 00:00:00
abstract::N-RAP is a recently discovered muscle-specific protein that is concentrated at the myotendon junctions in skeletal muscle and at the intercalated disks in cardiac muscle. The C-terminal half of N-RAP contains a region with sequence homology to nebulin, while a LIM domain is found at its N-terminus. N-RAP is hypothesiz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982395t
更新日期:1999-05-11 00:00:00
abstract::S-Adenosylmethionine decarboxylase is a pyruvate-dependent enzyme. The enzyme forms a Schiff base with substrate, S-adenosylmethionine, through the pyruvoyl moiety. This facilitates the release of CO2 from the substrate, which must then be protonated on the alpha carbon in order to permit hydrolysis of the Schiff base...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9825201
更新日期:1999-02-23 00:00:00
abstract::The azinomycins are a family of potent antitumor agents with the ability to form interstrand cross-links with DNA. This study reports on the unusual biosynthetic formation of the 5-methyl naphthoate moiety, which is essential for effective DNA association. While sequence analysis predicts that the polyketide synthase ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01050
更新日期:2016-02-02 00:00:00
abstract::Two-dimensional homonuclear and heteronuclear NMR and minimized potential energy calculations have been combined to define the structure of the antitumor agent mitomycin C (MC) cross-linked to deoxyguanosines on adjacent base pairs in the d(T1-A2-C3-G4-T5-A6).d(T7-A8-C9-G10-T11-A12) duplex. The majority of the mitomyc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00463a032
更新日期:1990-03-20 00:00:00
abstract::Reaction of poly(dA-[2'S-3H]dU) with activated bleomycin yields [3H]uracil propenal that completely retains the tritium label. In contrast, we have previously shown that reaction of poly(dA-[2'R-3H]dU) with activated bleomycin affords unlabeled uracil propenal [Wu, J. C., Kozarich, J. W., & Stubbe, J. (1983) J. Biol. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00369a037
更新日期:1986-10-21 00:00:00
abstract::The EcoRV restriction endonuclease cleaves DNA at its recognition sequence more readily with Mg2+ as the cofactor than with Mn2+ but, at noncognate sequences that differ from the EcoRV site by one base pair, Mn2+ gives higher rates than Mg2+. A mutant of EcoRV, in which an isoleucine near the active site was replaced ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9523926
更新日期:1996-02-13 00:00:00
abstract::The prothrombinase complex is comprised of an enzyme, factor Xa, and a cofactor, factor Va, that each bind peripherally to membranes containing phosphatidylserine (PS) and activate the substrate, prothrombin. The mechanism by which the membrane contributes to enhanced catalytic efficacy of prothrombinase is not precis...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi047655n
更新日期:2005-03-15 00:00:00
abstract::Ultrahigh-resolution X-ray diffraction data from cryo-cooled, B. lentus subtilisin crystals has been collected to a resolution of 0.78 A. The refined model coordinates have a rms deviation of 0.22 A relative to the same structure determined at room temperature and 2.0 A resolution. Several regions of main-chain and si...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9813983
更新日期:1998-09-29 00:00:00
abstract::We have performed comparative studies of the neutral glycosphingolipids synthesized by three human myeloid leukemia cell lines, K562, KG1, and HL-60, which were metabolically labeled with [14C]galactose, to evaluate changes in neutral glycosphingolipid synthesis with myeloid cell differentiation. Individual neutral gl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00345a034
更新日期:1985-11-19 00:00:00
abstract::The initial step of infection of blood cells with the human immunodeficiency virus, HIV, is the formation of a complex of the viral envelope protein gp120 and its human receptor CD4. We have examined structural features of recombinant soluble CD4 (sCD4) by chemical modification of arginine residues with hydroxyphenylg...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011626k
更新日期:2002-02-12 00:00:00
abstract::The amino acid composition and sequence of EIIMtl is known [Lee, C. A., & Saier, M. H., Jr. (1983) J. Biol. Chem. 258, 10761-10767]. This information was combined, in the present study, with quantitative amino acid analysis to determine the molar concentration of the enzyme. The stoichiometry of phosphoryl group incor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00415a020
更新日期:1988-07-26 00:00:00
abstract::The substrate specificity of the human enzyme glutathione reductase was changed from its natural substrate glutathione to trypanothione [N1,N8-bis(glutathionyl)spermidine] by site-directed mutagenesis of two residues. The glutathione analogue, trypanothione, is the natural substrate for trypanothione reductase, an enz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00239a006
更新日期:1991-06-25 00:00:00
abstract::We report the first experimental characterization of the full thermodynamic profile for binding of urea to a native protein. We measured the volumetric parameters of lysozyme at pH 7.0 as a function of urea within a temperature range of 18-45 °C. At neutral pH, lysozyme retains its native conformation between 0 and 8 ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00805
更新日期:2016-11-29 00:00:00
abstract::Multielectron multiproton reactions play an important role in both biological systems and chemical reactions involved in energy storage and manipulation. A key strategy employed by nature in achieving such complex chemistry is the use of proton-coupled redox steps. Cytochrome c nitrite reductase (ccNiR) catalyzes the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500854p
更新日期:2014-09-09 00:00:00
abstract::Escherichia coli tyrosine kinase (Etk) regulates the export of pathogenic capsular polysaccharide (CPS) by intermolecularly autophosphorylating its C-terminal tyrosine cluster. The kinase Etk, however, needs to be first activated by the intramolecular phosphorylation of a tyrosine residue, Y574, next to the active sit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900811p
更新日期:2009-08-25 00:00:00
abstract::Surface plasmon resonance (SPR) detection technology was employed to investigate the kinetic mechanism of deoxyadenosine kinase from Mycoplasma mycoides ssp. mycoides SC. In our experimental approach, the enzyme was attached to the sensor surface, the reactants were injected in the mobile phase, and the product-enzyme...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0515523
更新日期:2006-01-17 00:00:00
abstract::The structure/function properties of functional groups in the leadzyme have been studied by assaying the activity of analog ribozymes generated by the systematic substitution of modified nucleotides in the internal loop region of the ribozyme. Guanosine analogs introduced at positions 4 and 7 occupied by guanosine in ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962219p
更新日期:1997-03-18 00:00:00
abstract::Familial British dementia (FBD) is a rare neurodegenerative disorder and shares features with Alzheimer's disease, including amyloid plaque deposits, neurofibrillary tangles, neuronal loss, and progressive dementia. Immunohistochemical and biochemical analysis of plaques and vascular amyloid of FBD brains revealed tha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi002287i
更新日期:2001-03-27 00:00:00