Abstract:
:We synthesized the following four new peptide substrates, Suc-Phe-Leu-pNA, Suc-Phe-Leu-NMec, Suc-Phe-Leu-ONPh, and Pht-Phe-Leu-pNA, and we applied the proton inventory method to their hydrolysis by papain. Useful relationships between the rate constants of the catalytic reaction have been established and contributed to the elucidation of the hydrolytic mechanism of papain. For all amide substrates, the parameter K(S) and the rate constants k(1), k(-)(1), and k(2) were estimated. Moreover, it was found that k(cat)/K(m) = k(1) for all four substrates, while two exchangeable hydrogenic sites, one in the ground state and another in the transition state, generate an inverse isotope effect during the reaction governed by this parameter. The proton inventories of both k(2) and k(3) are essentially linear, whatever the acyl moiety and/or the leaving group of the substrate. The proton inventories of K(S) are also essentially linear for all amide substrates, while the observed large isotope effect of about 3 to 9 originates from a single hydrogenic site in the product state. This latter, in agreement to both the small transition state fractionation factors found for k(cat)/K(m) (or k(1)) and the unit ground-state fractionation factors found for k(2), argues for the formation of a tetrahedral adduct during the reaction governed by the k(1) parameter. Furthermore, papain acts as a one-proton catalyst during acylation or deacylation, both of which proceed through similar concerted reaction pathways, where a nucleophilic attack is accompanied by the movement of one proton.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Theodorou LG,Lymperopoulos K,Bieth JG,Papamichael EMdoi
10.1021/bi001615bsubject
Has Abstractpub_date
2001-04-03 00:00:00pages
3996-4004issue
13eissn
0006-2960issn
1520-4995pii
bi001615bjournal_volume
40pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The membrane-bound closed channel structure of helices 4 and 5 (Lys-406-Asp-446) of the colicin E1 channel domain was investigated by using a site-directed fluorescence labeling technique. A bimane probe was covalently attached to a cysteine residue in a series of single-cysteine mutant proteins to scan each helix in ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801906v
更新日期:2009-02-17 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::Sequence-specific DNA binding proteins generally consist of more than two DNA-contacting regions to ensure the selectivity of recognition. The multiple DNA binding modules are connected either through the covalent linker or through the noncovalent dimerization domain. We have compared the DNA binding of peptide dimers...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981743o
更新日期:1999-02-02 00:00:00
abstract::Electrophilic halogenating agents, including hypohalous acids and haloamines, oxidize free methionine and the N-terminal methionines of peptides and proteins (e.g., Met-1 of anti-inflammatory peptide 1 and ubiquitin) to produce dehydromethionine (a five-membered isothiazolidinium heterocycle). Amide derivatives of met...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901343d
更新日期:2009-11-24 00:00:00
abstract::Formylglycinamide ribonucleotide amidotransferase (FGAR-AT) catalyzes the ATP- and glutamine-dependent formation of formylglycinamidine ribonucleotide, ADP, P(i), and glutamate in the fourth step of de novo purine biosynthesis. Like all amidotransferases (ATs), FGAR-AT is proposed to channel ammonia between a glutamin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049127h
更新日期:2004-08-17 00:00:00
abstract::Achieving a satisfactory biochemical explanation for the opportunistic underwater adhesion of marine invertebrates such as mussels and barnacles requires a detailed characterization of proteins extracted from holdfast structures produced by these organisms. Mefp-5 is an adhesive protein derived from the foot of the co...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi002718x
更新日期:2001-03-06 00:00:00
abstract::Hemocyanin (Hc) is a dinuclear copper protein that binds oxygen reversibly. The structure of the Cu(II) site in a derivative of hemocyanin known as green half-met (GHM) has been analyzed using the pulsed EPR technique of electron spin-echo envelope modulation (ESEEM) spectroscopy. The derivative, prepared by treating ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00005a007
更新日期:1995-02-07 00:00:00
abstract::The enhancement of the longitudinal proton relaxation rate of solvent water protons which occurs when Mn(II) is bound to the "tight" metal ion site of unadenylylated glutamine synthetase (GS) was used to determine the binding constant of L-methionine (SR)-sulfoximine to GS-Mn(II) complexes. The binary enhancement for ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00648a014
更新日期:1976-02-10 00:00:00
abstract::Rhodospirillum rubrum ribulose bisphosphate carboxylase contains two high affinity binding sites for pyridoxal phosphate and two catalytic sites per dimer. However, pyridoxal phosphate binding at only one site is sufficient for inactivation of both catalytic sites. In the presence of 20 mM bicarbonate, 10 mM magnesium...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00600a024
更新日期:1978-04-04 00:00:00
abstract::Catalase-peroxidases (KatGs) are unique bifunctional heme peroxidases with an additional posttranslationally formed redox-active Met-Tyr-Trp cofactor that is essential for catalase activity. On the basis of studies of bacterial KatGs, controversial mechanisms of hydrogen peroxide oxidation were proposed. The recent di...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00436
更新日期:2016-06-28 00:00:00
abstract::Merozoite surface protein 2 (MSP2), an abundant glycosylphosphatidylinositol-anchored protein on the surface of Plasmodium falciparum merozoites, is a promising malaria vaccine candidate. MSP2 is intrinsically disordered and forms amyloid-like fibrils in solution under physiological conditions. The 25 N-terminal resid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi201880s
更新日期:2012-02-21 00:00:00
abstract::The substrate analogue 2-(1-carboxy-2-phenylethyl)-4-phenylazophenol is a potent competitive inhibitor of carboxypeptidase A. Upon ligation to the active site, the azophenol moiety undergoes a shift of pKa from a value of 8.76 to a value of 4.9; this provides an index of the Lewis acidity of the active site zinc ion. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00358a028
更新日期:1986-05-20 00:00:00
abstract::The zinc metalloenzyme protein farnesyltransferase (FTase) catalyzes the alkylation of a cysteine residue of protein substrates with a 15 carbon farnesyl group. We have developed fluorescence assays to directly measure the affinity of the enzyme for peptide and protein (Ras) substrates. A peptide corresponding to the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981525v
更新日期:1998-11-03 00:00:00
abstract::Chloride intracellular channel protein 1 (CLIC1) functions as an anion channel in plasma and nuclear membranes when its soluble monomeric form converts to an integral-membrane form. The transmembrane region of CLIC1 is located in its thioredoxin-like domain 1, but the mechanism whereby the protein converts to its memb...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9010607
更新日期:2009-09-08 00:00:00
abstract::The role of the tryptophan residues in the substrate-binding and catalytic mechanism of an enzymatically active C-terminal fragment of Pseudomonas aeruginosa exotoxin A was studied by individually or jointly replacing these residues with phenylalanine. Substitution of W-466 decreased the ADP-ribosyltransferase and NAD...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961985t
更新日期:1996-12-03 00:00:00
abstract::Endogenous protein kinase inhibitors are essential for a wide range of physiological functions. These endogenous inhibitors may mimic peptide substrates as in the case of the heat-stable protein kinase inhibitor (PKI), or they may mimic nucleotide triphosphates. Natural product inhibitors, endogenous to the unique org...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9820659
更新日期:1999-02-23 00:00:00
abstract::The laminin alpha3 chain is mainly expressed at the skin, and its C-terminal G domain has a critical role in multiple biological functions. We screened for biologically active sites on the mouse laminin alpha3 chain G domain using 107 synthetic peptides on coated plates and conjugated to Sepharose beads with HT1080 hu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901421t
更新日期:2009-11-10 00:00:00
abstract::G-protein-coupled receptors (GPCRs) represent the largest class of drug targets, accounting for more than 40% of marketed drugs; however, discovery efforts for many GPCRs have failed to provide viable drug candidates. Historically, drug discovery efforts have focused on developing ligands that act at the orthosteric s...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi200129s
更新日期:2011-04-05 00:00:00
abstract::Aminoimidazole riobnucleotide carboxylase, the sixth step in the purine biosynthetic pathway, catalyzes the conversion of aminoimidazole ribonucleotide (AIR) to carboxyaminoimidazole ribonucleotide (CAIR). The gene products of the purE and purK genes (PurE and PurK, respectively) thought to be responsible for this act...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00136a016
更新日期:1992-06-02 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::Thermal unfolding of discoidal complexes of apolipoprotein (apo) C-1 with dimyristoyl phosphatidylcholine (DMPC) reveals a novel mechanism of lipoprotein stabilization that is based on kinetics rather than thermodynamics. Far-UV CD melting curves recorded at several heating/cooling rates from 0.047 to 1.34 K/min show ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025588w
更新日期:2002-06-11 00:00:00
abstract::A nine-base oligodeoxyribonucleotide complementary to bases 2497-2505 of 23S rRNA was hybridized to both 50S subunits and 70S ribosomes. The binding of the probe to the ribosome or ribosomal subunits was assayed by nitrocellulose filtration and by sucrose gradient centrifugation techniques. The location of the hybridi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00428a073
更新日期:1989-01-24 00:00:00
abstract::NADH oxidase activity has been detected in luminal membrane derived from the proximal tubules of rat kidney (brush border membranes). The cytochromes associated with these membranes [García, M.L., Benavides, J., Valdivieso, F., Mayor, F., & Giménez-Gallego, G. (1978) Biochem. Biophys. Res. Commun. 82, 738-744] were re...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00562a019
更新日期:1980-10-14 00:00:00
abstract::A crude in vitro system which initiates chloroplast DNA synthesis near the D-loop site mapped by electron microscopy [Wu, M., Lou, J. K., Chang, D. Y., Chang, C. H., & Nie, Z. Q. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 6761-6765] consists of soluble proteins and proteins extracted from purified thylakoid membrane. In...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00218a034
更新日期:1991-01-29 00:00:00
abstract::The complete sequence of histone 2B of Drosophila has been determined by using an improved Beckman sequenator. Comparing these data with those previously published by other investigators on the histone 2B of calf [Iwai, K., Hayashi, H., & Ishikawa, K. (1972) J. Biochem. (Tokyo) 72, 357--367], trout [Koostra, A., & Bai...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00592a025
更新日期:1979-12-11 00:00:00
abstract::To determine whether ligand-receptor interactions could engender the selective uptake by deficient cells of enzyme-laden liposomes, aggregated human IgG was used to coat liposomes which had previously trapped purified hexosaminidase A (Hex A). By a new, high-yield procedure, Hex A was purified 7000-fold from human pla...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00647a034
更新日期:1976-01-27 00:00:00
abstract::The proton transport membrane protein bacteriorhodopsin has been biosynthetically labeled with [methyl-13C]methionine and studied by high-resolution 13C NMR after solubilization in the detergent Triton X-100. The nine methionine residues of bacteriorhodopsin give rise to four well-resolved 13C resonances, two of which...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00230a012
更新日期:1991-04-23 00:00:00
abstract::In a previous paper, we reported the presence of globoside as a major neutral glycolipid in PC12 pheochromocytoma cells [Ariga, T., Macala, L. J., Saito, M., Margolis, R. K., Greene, L. A., Margolis, R. U., & Yu, R. K. (1988) Biochemistry 27, 52-58]. Recently, we found that subcloned PC12h cells accumulated another un...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00414a058
更新日期:1988-07-12 00:00:00
abstract::The effect on overall alpha-helix content of substituting proline for alanine has been determined at 5 positions (1, 2, 4, 5, and 13) of a 13-residue peptide related in sequence to residues 1-13 of ribonuclease A. The helix content falls off rapidly as proline is moved inward, and the proline residue effectively trunc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00237a026
更新日期:1991-06-11 00:00:00
abstract::Porcine parathyroid gland slices were incubated with 3H-labeled amino acids in order to label tissue proteins. After incubation a crude hormonal extract was prepared and analyzed by chromatography on carboxymethylcellulose. Among the three radioactive peaks which were detected in the eluate, two were identified as par...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00687a018
更新日期:1975-08-12 00:00:00