Abstract:
:In bee venom phospholipase A2, histidine-34 probably functions as a Brønsted base to deprotonate the attacking water. Aspartate-64 and tyrosine-87 form a hydrogen bonding network with histidine-34. We have prepared mutants at these positions and studied their kinetic properties. The mutant in which histidine-34 is changed to glutamine is catalytically inactive, while the mutants in which aspartate-64 is changed to asparagine or alanine (interfacial turnover numbers are reduced by 50-100-fold) or in which tyrosine-87 is changed to phenylalanine (no change in turnover number) retain good activity. The interfacial Michaelis constants are changed by less than 10-fold for all mutants. Molecular simulations suggest that mutation of aspartate-64 and tyrosine-87 should yield enzymes that retain a native-like structure and support catalysis. The pKa of the histidine-34 imidazole was deduced from the pH-rate profile and from the pH dependence of the rate of histidine-34 alkylation by 2-bromo-4'-nitroacetophenone. The pKa is increased about one-half unit by the tyrosine-87 mutation and reduced about one-half unit by the aspartate-64 to asparagine mutation, while in the aspartate-64 to alanine mutant the pKa is unchanged. These pKas are generally consistent with results of electrostatic calculations and suggest that the hydrogen bond between aspartate-64 and histidine-34 is not unusually strong. The hydrogen bonding network linking tyrosine-87 to aspartate-64 and aspartate-64 to histidine-34 is not critical for catalysis.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Annand RR,Kontoyianni M,Penzotti JE,Dudler T,Lybrand TP,Gelb MHdoi
10.1021/bi9528412subject
Has Abstractpub_date
1996-04-09 00:00:00pages
4591-601issue
14eissn
0006-2960issn
1520-4995pii
bi9528412journal_volume
35pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Factor IX activation by factor XIa is thought to proceed through the singly-cleaved free intermediate, factor IX alpha. However, we observed no intermediate development during factor IX activation by factor XIa when using a low substrate to enzyme ratio (44:1 mol/mol). This result can be explained by one of two mechan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962274y
更新日期:1997-04-08 00:00:00
abstract::Protein binding specificities can be manipulated by redesigning contacts that already exist at an interface or by expanding the interface to allow interactions with residues adjacent to the original binding site. Previously, we developed a strategy, called AnchorDesign, for expanding interfaces around linear binding e...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00408
更新日期:2018-07-31 00:00:00
abstract::We investigated the molecular mechanisms and the binding site location for the fluorophor crystal violet (CrV), a noncompetitive antagonist of the nicotinic acetylcholine receptor (AChR). To this end, radiolabeled competition binding, fluorescence spectroscopy, Schild-type analysis, patch-clamp recordings, and molecul...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi051752e
更新日期:2006-02-21 00:00:00
abstract::A positional-scanning combinatorial protocol was employed to optimize the deoxyribose-based cleavage of B-form DNA by Ni(II) x Xaa-Xaa-His metallopeptides. This procedure employed 18 naturally occurring amino acids (excluding Cys and Trp) to generate two libraries in which the first and second positions of the peptide...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982587o
更新日期:1999-02-16 00:00:00
abstract::Stabilization of the plasma membrane Ca-ATPase (PMCA) in an inactive conformation upon oxidation of multiple methionines in the calcium regulatory protein calmodulin (CaM) is part of an adaptive cellular response to minimize ATP utilization and the generation of reactive oxygen species (ROS) under conditions of oxidat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0474113
更新日期:2005-03-29 00:00:00
abstract::Dehydroquinate synthase has been purified 9000-fold from Escherichia coli K-12 (strain MM294). The synthase is encoded by the aroB gene, which is carried by plasmid pLC29-47 from the Carbon-Clarke library. Construction of an appropriate host bearing pLC29-47 results in a strain that produces 20 times more enzyme than ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00314a036
更新日期:1984-09-11 00:00:00
abstract::We find that specific oxidation for the Met-192 residue in delta-chymotrypsin to methionine sulfoxide results in a twofold increase in Km(app) and unchanged kcat in the hydrolysis of N-acetyl mono(amino acid) amide substrates. However, the catalyzed hydrolyses of N-acetyl dipeptide amide substrates by (methionine sulf...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00664a006
更新日期:1976-09-21 00:00:00
abstract::Fas and its ligand (FasL) are members of the tumor necrosis factor receptor (TNFR) and tumor necrosis factor (TNF) superfamilies, respectively. Fas-FasL interactions trigger controlled cell death (apoptosis) in the immune system and thus play a key role in the regulation of immune responses. Structural details of the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972959d
更新日期:1998-03-17 00:00:00
abstract::Adenosine cyclic 3',5'-phosphate receptor protein (CRP or CAP) is a regulatory protein involved in the transcription of several operons in Escherichia coli. cAMP-independent, nonspecific complexes of CRP and DNA were investigated by photochemical cross-linking of the protein to nonspecific DNA, whose thymines are subs...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00058a010
更新日期:1993-02-23 00:00:00
abstract::In mammalian cells, the incorporation of the 21st amino acid, selenocysteine, into proteins is guided by the Sec machinery. The function of this protein complex requires several protein-protein and protein-RNA interactions, leading to the incorporation of selenocysteine at UGA codons. It is guided by stem-loop structu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b01116
更新日期:2017-05-02 00:00:00
abstract::Squid cartilage chondroitin sulfate E (CS-E) exhibits various biological activities, including anticoagulant activities, lymphoid regulatory activities, and neuroregulatory activities [Ueoka, C., Kaneda, N., Okazaki, I., Nadanaka, S., Muramatsu, T., and Sugahara, K. (2000) J. Biol. Chem. 275, 37407-37413]. These activ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi015577n
更新日期:2001-10-23 00:00:00
abstract::The role of pyridoxal 5'-phosphate (PLP) in the radical-mediated amino group migration catalyzed by lysine 2,3-aminomutase from Clostridia SB4 has been investigated by electron spin echo envelope modulation (ESEEM) spectroscopy. This pulsed electron paramagnetic resonance (EPR) method was used to estimate the distance...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00031a033
更新日期:1995-08-08 00:00:00
abstract::Evidence of nonequilibrium local heating in transient spectra of LHCII, the main light-harvesting complex of plants, was studied by using various excitation intensities over a wide temperature range, from 10 K to room temperature. No obvious manifestation of local heating was found at room temperature, whereas at 10 K...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060048a
更新日期:2006-08-08 00:00:00
abstract::Snapshots of three consecutive steps in the proteolytic reaction of HIV-1 protease (PR) were obtained in crystal structures at resolutions of 1.2-1.4 Å. Structures of wild-type protease and two mutants (PR(V32I) and PR(I47V)) with V32I and I47V substitutions, which are common in drug resistance, reveal the gem-diol te...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi3008092
更新日期:2012-10-02 00:00:00
abstract::The nitrite anion is known to oxidize and degrade hemoglobin (Hb). Recent literature reports suggest a nitrite reductase activity for Hb, converting nitrite into nitric oxide. Surprisingly, no structural information about Hb-nitrite interactions has been reported. We have determined the crystal structure of the ferric...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801015c
更新日期:2008-08-12 00:00:00
abstract::A preparation consisting of isolated dimeric peripheral antenna complexes from green plant photosystem I (light-harvesting complex I or LHCI) has been characterized by means of (polarized) steady-state absorption and fluorescence spectroscopy at low temperatures. We show that this preparation can be described reasonab...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0007369
更新日期:2000-07-25 00:00:00
abstract::This study highlights the effect of incorporation of locked nucleic acid (LNA) on improving the functional efficacy of DNAzymes against microRNAs (antagomirzymes). DNAzymes were designed against two different sites of miR-27a, which were encompassed both within the precursor and mature form of miRNA. The cleavage and ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101185k
更新日期:2010-11-09 00:00:00
abstract::Liver alcohol dehydrogenase (LADH) carboxymethylated at Cys-46 (CMLADH) forms two different ternary complexes with 4-trans-(N,N-dimethylamino)cinnamaldehyde (DACA). The complex with reduced nicotinamide adenine dinucleotide (NADH) is characterized by a 38-nm red shift of the long-wavelength pi, pi* transition to 436 n...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00321a085
更新日期:1984-12-18 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
abstract::New homo- and heterobifunctional cross-linking reagents have been synthesized. These reagents are based on ortho ester, acetal, and ketal functionalities that undergo acid-catalyzed dissociation but are base stable. The protein-reactive group in all the homobifunctional reagents is a maleimide group; the heterobifunct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00432a023
更新日期:1989-03-21 00:00:00
abstract::The ionic and nucleotide requirements for the in vitro polymerization of microtubules from purified brain tubulin have been characterized by viscometry. Protein was purified by successive cycles of a temperature dependent assembly-diassembly scheme. Maximal polymerization occurred at a concentration of 0.1 M Pipes (pi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00684a032
更新日期:1975-07-01 00:00:00
abstract::Beta-catenin phosphorylation at serine 45 (Ser45), threonine 41 (Thr41), Ser37, and Ser33 is critical for beta-catenin degradation, and regulation of beta-catenin phosphorylation is a central part of the canonical Wnt signaling pathway. Beta-catenin mutations at Ser45, Thr41, Ser37, and Ser33 perturb beta-catenin degr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0601149
更新日期:2006-04-25 00:00:00
abstract::The role of the interaction between actin and the secondary actin binding site of myosin (segment 565-579 of rabbit skeletal muscle myosin, referred to as loop 3 in this work) has been studied with proteolytically generated smooth and skeletal muscle myosin subfragment 1 and recombinant Dictyostelium discoideum myosin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991595h
更新日期:1999-11-16 00:00:00
abstract::The inheritance of DNA methylation patterns may play an important role in the stability of the differentiated state. We have therefore studied the inhibitory effects of DNA binding proteins on DNA methylation in vitro. Mouse L1210 cells grown in the presence of 5-azacytidine acquire hemimethylated sites in their DNA. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00326a021
更新日期:1985-02-26 00:00:00
abstract::The HIV-1 virulence factor Nef interacts with the macrophage Src-family kinase Hck, resulting in constitutive kinase activation that contributes to viral replication and immune escape. Previous chemical library screens identified the diphenylfuranopyrimdine kinase inhibitor DFP-4AB, which selectively inhibits Nef-depe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00875
更新日期:2015-10-20 00:00:00
abstract::The oxidation of alcohol to aldehyde by horse liver alcohol dehydrogenase (LADH) requires the transfer of a hydride ion from the alcohol substrate to the cofactor nicotinamide adenine dinucleotide (NAD). A quantum mechanical tunneling contribution to this hydride transfer step has been demonstrated in a number of LADH...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi973184b
更新日期:1998-06-30 00:00:00
abstract::Lateral mobilities of fluorescent cell surface probes have been measured on normal (3T3) and transformed (SV3T3) cultured mouse fibroblasts. There is little discernible difference in the mobilities of a lipid analogue (diI), a fluorescent ganglioside derivative (GM1), and tetramethylrhodamine-labeled succinylated conc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00551a011
更新日期:1980-05-13 00:00:00
abstract::Specific interactions of human melanocortin-4 receptor (hMC4R) with its nonpeptide and peptide agonists were studied using alanine-scanning mutagenesis. The binding affinities and potencies of two synthetic, small-molecule agonists (THIQ, MB243) were strongly affected by substitutions in transmembrane alpha-helices (T...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0501840
更新日期:2005-08-30 00:00:00
abstract::The time-resolved fluorescence decay of plant PSI-LHCI has been analyzed and compared with its component parts, the PSI core and the peripheral antenna LHCI, in an attempt to (i) define the physical domains associated with the multicomponent decay-associated spectra (DAS) and determine the origin of the kinetically sl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060243p
更新日期:2006-06-06 00:00:00
abstract::In order to elucidate the molecular mechanisms responsible for the apparent nonlinear behavior of the temperature dependence of the redox potential of Hydrogenobacter thermophilus cytochrome c552 [Takahashi, Y., Sasaki, H., Takayama, S. J., Mikami, S., Kawano, S., Mita, H., Sambongi, Y., and Yamamoto, Y. (2006) Bioche...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7000714
更新日期:2007-08-14 00:00:00