Abstract:
:Ks values for binding of selected substrates, competitive inhibitors, and a noncompetitive inhibitor were found to be similar for alpha-chymotrypsin and N-methyl-alpha-chymotrypsin. The rates and steps of binding of a competitive inhibitor and a noncompetitive inhibitor were also found to be similar for alpha-chymotrypsin and N-methyl-alpha-chymotrypsin. Therefore, N-methyl-alpha-chymotrypsin is an appropriate model for alpha-chymotrypsin in studying the dynamics of the binding of substrates by temperature-jump techniques in aqueous solvents. 2-Toluidinylnaphthalene-6-sulfonate, a noncompetitive inhibitor, bound to alpha-chymotrypsin in a single step with rate constants k1 and k-1 of 3.9 X 10(7) M-1 s-1 and 1.9 X 10(3) s-1, respectively, at pH 5.0 (0.2 M acetate, ionic strength of 0.2). Similar values were obtained for N-methyl-alpha-chymotrypsin and chymotrypsinogen A at pH 5.0 and for alpha-chymotrypsin at pH 7.8 [0.1 M tris(hydroxymethyl)aminomethane-0.03 M CaCl2]. Indole, a competitive inhibitor, bound to alpha-chymotrypsin in a single step at pH 5.0 and 7.8, with k1 and k-1 of 1.8 X 10(7) M-1 s-1 and 7.8 X 10(3) s-1, respectively, at pH 5.0 while proflavin, another competitive inhibitor, bound to alpha-chymotrypsin with two observable steps where k1, k-1, k2, and k-2 were 1.0 X 10(7) M-1 s-1, 7 X 10(2) s-1, 1.0 X 10(3) s-1, and 7 X 10(2) s-1, respectively, at pH 5.0. The specific substrate N-acetyl-L-3,5-dinitrotyrosine ethyl ester bound to N-methyl-alpha-chymotrypsin at pH 5.0 in three observable steps where k1, k-1, k2, k-2, k3, and k-3 were 3.7 X 10(7) M-1 s-1, 6.2 X 10(4) s-1, 1.2 X 10(3) s-1, 3.5 X 10(2) s-1, 3 X 10(2) s-1, and 4 X 10(2) s-1, respectively. Preliminary data indicated that the third step of this reaction is probably absent when Met192 of N-methyl-alpha-chymotrypsin is oxidized to methionine sulfoxide. These results confirm the validity of data obtained from reactions at subzero temperatures in 65% dimethyl sulfoxide in indicating multiple steps in the binding of substrates to alpha-chymotrypsin. The methodology described should make it possible to measure quantitatively the contribution of the binding process to enzyme catalysis (the Circe effect).
journal_name
Biochemistryjournal_title
Biochemistryauthors
Maehler R,Whitaker JRdoi
10.1021/bi00262a017subject
Has Abstractpub_date
1982-09-14 00:00:00pages
4621-33issue
19eissn
0006-2960issn
1520-4995journal_volume
21pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Metal homeostasis and resistance in bacteria is maintained by a panel of metal-sensing transcriptional regulators that collectively control transition metal availability and mediate resistance to heavy metal xenobiotics, including As(III), Cd(II), Pb(II), and Hg(II). The ArsR family constitutes a superfamily of metal ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100490u
更新日期:2010-08-10 00:00:00
abstract::Dipeptide substrates for metalloendoproteases have previously been shown to block biological processes requiring membrane fusion. Thus, we employed such compounds as potential inhibitors of the insulin-dependent activation of glucose transport in fat cells. This event is thought to involve vesicle movement from an int...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00361a031
更新日期:1986-07-01 00:00:00
abstract::We have previously shown that introduction of an engineered Met160 residue in ascorbate peroxidase (S160M variant) leads to the formation of a covalent link between Met160 and the heme vinyl group [Metcalfe, C. L., et al. (2004) J. Am. Chem. Soc. 126, 16242-16248]. In this work, we have used electronic spectroscopy, H...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7015316
更新日期:2007-11-20 00:00:00
abstract::Organisms and cellular systems which have adapted to stresses such as high temperature, desiccation, and urea-concentrating environments have responded by concentrating particular organic solutes known as osmolytes. These osmolytes are believed to confer protection to enzyme and other macromolecular systems against su...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00138a006
更新日期:1992-06-16 00:00:00
abstract::STRA6 is a multitransmembrane domain protein not homologous to any other proteins with known function. It functions as the high-affinity receptor for plasma retinol binding protein (RBP) and mediates cellular uptake of vitamin A from the vitamin A-RBP complex. Consistent with the diverse roles of vitamin A and the wid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi8002082
更新日期:2008-05-13 00:00:00
abstract::The marked difference between the intra- and extracellular 31P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the 31P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00424a017
更新日期:1988-11-29 00:00:00
abstract::N-(1-Pyrenyl)iodoacetamide has been used to introduce fluorescent probes into Escherichia coli RNA polymerase. After an incubation time of 15 min, approximately 2 pyrene equiv was introduced per enzyme molecule. There was no further increase in modification after more extended periods of incubation. Neither calf thymu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00215a028
更新日期:1991-01-08 00:00:00
abstract::The aromatic residues of fd coat protein in sodium dodecyl sulfate micelles are characterized by 1H and 13C NMR. Resonances from both types of nuclei show structure-induced chemical shift dispersion and line widths indicative of a folded native structure for the protein. The two tyrosines were found to have pKas of 12...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00505a010
更新日期:1981-01-20 00:00:00
abstract::The potassium form of d(CGCGAATTCGCG) solved by X-ray diffraction to 1.75 A resolution indicates that monovalent cations penetrate the primary and secondary layers of the "spine of hydration". Both the sodium [Shui, X., McFail-Isom, L., Hu, G. G., and Williams, L. D. (1998) Biochemistry 37, 8341-8355] and the potassiu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982063o
更新日期:1998-12-01 00:00:00
abstract::The equilibrium binding and association kinetics of the Saccharomyces cerevisiae TATA Binding Protein (TBP) to the E4 and Major Late promoters of adenovirus (TATATATA and TATAAAAG, respectively), have been directly compared by quantitative DNase I titration and quench-flow "footprinting". The equilibrium binding of TB...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981072u
更新日期:1998-11-10 00:00:00
abstract::Triglyceride analogues were synthesized in which one of the primary acyl ester functions has been replaced by an alkyl group and the secondary acyl ester bond has been replaced by an acyl amino bond. The chain length at either position was varied, and both (R)- and (S)-enantiomers of each compound were synthesized. Th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00019a020
更新日期:1995-05-16 00:00:00
abstract::G proteins play an important role in transmitting hormonal signals, and fluorescence techniques would be useful to study their cellular distribution and mechanisms. To prepare active fluorescent G protein Go/Gi or beta gamma subunits were reacted with fluorescein isothiocyanate (FITC) to label the alpha (F-alpha) and ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00060a035
更新日期:1993-03-09 00:00:00
abstract::Radical S-adenosyl-L-methionine, cobalamin-dependent methyltransferases have been proposed to catalyze the methylations of unreactive carbon or phosphorus atoms in antibiotic biosynthetic pathways. To date, none of these enzymes has been purified or shown to be active in vitro. Here we demonstrate the activity of the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi201220r
更新日期:2011-10-25 00:00:00
abstract::We report nuclear magnetic resonance (NMR) data indicating that the Rieske protein from the cytochrome bc complex of Thermus thermophilus (TtRp) undergoes modest redox-state-dependent and ligand-dependent conformational changes. To test models concerning the mechanism by which TtRp transfers between different sites on...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400296c
更新日期:2013-04-30 00:00:00
abstract::19F NMR spectroscopic properties of glycogen phosphorylase reconstituted with 6-fluoropyridoxal (6-FPAL) and 6-fluoropyridoxal phosphate (6-FPLP) were investigated. Analysis of the contribution of chemical shift anisotropy to the line width of the 6-FPLP-enzyme signal shows that the coenzyme molecule is tightly bound ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00356a015
更新日期:1986-04-22 00:00:00
abstract::The crystal structure of the particulate methane monooxygenase (pMMO) from Methylococcus capsulatus (Bath) has been reported recently [Lieberman, R. L., and Rosenzweig, A. C. (2005) Crystal structure of a membrane-bound metalloenzyme that catalyses the biological oxidation of methane, Nature 434, 177-182]. Subsequent ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700883g
更新日期:2007-12-04 00:00:00
abstract::A panel of 10 hybridomas was assembled to assess the influence of various genetic and biological factors upon glycosylation of secreted monoclonal IgG. After exhaustive Pronase digestion of IgG, glycopeptides were characterized chromatographically by apparent size, charge, and concanavalin A (Con A)-Sepharose and Lens...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00429a065
更新日期:1989-02-07 00:00:00
abstract::Cytomegaloviruses (CMVs) are ubiquitous species-specific viruses that establish acute, persistent, and latent infections. Both human and mouse CMVs encode proteins that inhibit the activation of natural killer (NK) cells by downregulating cellular ligands for the NK cell activating receptor, NKG2D. The MCMV glycoprote...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi902130j
更新日期:2010-03-23 00:00:00
abstract::In order to compare the interfacial behavior of the polyheme cytochromes c which belong to the cytochrome c3 superfamily, the monomolecular film technique was used to determine whether and how these metalloproteins interact with (phospho)lipids). Measurements of the variations of surface pressure and surface potential...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00036a005
更新日期:1995-09-12 00:00:00
abstract::The thermal dependence of the structural stability of membrane-reconstituted yeast cytochrome c oxidase has been studied by using different techniques including high-sensitivity differential scanning calorimetry, differential detergent solubility thermal gel analysis, and enzyme activity measurements. For these studie...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00455a028
更新日期:1990-01-23 00:00:00
abstract::Unfractionated Escherichia coli tRNA has been aminoacylated with lysine and preferentially acetylated at the epsilon-amino nitrogen of lysine by reaction with N-acetoxysuccinimide. After treatment with peptidyl-tRNA hydrolase, 90% of the aminoacylated tRNA molecules were Nepsilon-acetyl-Lys-tRNA. Post-ribosomal supern...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00648a018
更新日期:1976-02-10 00:00:00
abstract::The addition of a small peptide can significantly increase the rate at which pepsin cleaves a substrate at pH 4.5. Why? In order to find out, we have determined spectrophotometrically the relative ability of over a dozen peptides to speed the initial rate of disappearance of Phe-Trp-NH2 and Leu-Trp-Met-Arg. Here are s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00514a029
更新日期:1981-05-26 00:00:00
abstract::A bifunctional molecule was genetically engineered which contained an amino-terminal effector domain that bound immunoglobulin Fc (fragment B of staphylococcal protein A) and a carboxyl-terminal domain that bound digoxin [a single-chain Fv (sFv)]. Effector and sFv binding properties were virtually identical with those...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00487a005
更新日期:1990-09-04 00:00:00
abstract::HSC70 interacting protein (HIP) is an essential cytoplasmic cochaperone involved in the regulation of HSC70 chaperone activity and the maturation of progesterone receptor. To determine the quaternary structure and the gross conformation of the protein in solution, a wide array of biochemical and biophysical techniques...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9917535
更新日期:2000-01-18 00:00:00
abstract::Thiol dioxygenases are mononuclear non-heme FeII-dependent metalloenzymes that initiate the oxidative catabolism of thiol-containing substrates to their respective sulfinates. Cysteine dioxygenase (CDO), the best characterized mammalian thiol dioxygenase, contains a three-histidine (3-His) coordination environment rat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00267
更新日期:2020-07-07 00:00:00
abstract::Tafazzin is the mitochondrial enzyme that catalyzes transacylation between a phospholipid and a lysophospholipid in remodeling. Mutations in tafazzin cause Barth syndrome, a potentially life-threatening disease with the major symptom being cardiomyopathy. In the tafazzin-deficient heart, cardiolipin (CL) acyl chains b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00042
更新日期:2018-04-10 00:00:00
abstract::Nicotinic acid phosphoribosyltransferase (NAPRTase; EC 2.4.2.11) forms nicotinic acid mononucleotide (NAMN) and PPi from 5-phosphoribosyl 1-pyrophosphate (PRPP) and nicotinic acid (NA). The Vmax NAMN synthesis activity of the Salmonella typhimurium enzyme is stimulated about 10-fold by ATP, which, when present, is hyd...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9720134
更新日期:1998-03-24 00:00:00
abstract::Thermal unfolding/refolding studies of the three tropomyosin dimers, alpha alpha, alpha beta, and beta beta, from chicken gizzard muscle were performed to explain the preferential assembly of alpha- and beta-tropomyosin subunits into heterodimers, alpha beta [Lehrer, S. S., & Qian, Y. (1989) J. Biol. Chem. 265, 1134]....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00237a007
更新日期:1991-06-11 00:00:00
abstract::The catalytic (C) subunit of cAMP-dependent protein kinase interacts with two classes of inhibitors. The regulatory (R) subunits, types I and II, associate to form an inactive holoenzyme complex that is activated in response to cAMP. The C-subunit is also inhibited by small heat-stable protein kinase inhibitors (PKI's...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00213a035
更新日期:1993-12-21 00:00:00
abstract::The complete amino acid sequence of the major component myoglobin from Amazon River dolphin, Inia geoffrensis, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. Three easily separable peptides were obtained by cleaving the protein with cy...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00695a018
更新日期:1975-12-02 00:00:00