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 GS-Mn(II) is 22 at 24 MHz, 25 degrees C. The enhancement is lowered in the presence of the sulfoximine and the computed dissociation constant is 30 muM with epsilont, the enhancement for the ternary complex, equal to 3.0. Titration curves for the sulfoximine were also obtained in the presence of Mg-ADP, Mg-ADP plus Pi, and Mg-ATP. The dissociation constants were 9, 5, and 0.8 muM, respectively. The progressive tightening of the dissociation constants is symptomatic of conformational changes at the active site as the total subsite occupied by ATP is filled. The number of rapidly exchanging water molecules drops from 2 to approximately 0.1 when saturating concentrations of L-methionine (SR)-sulfoximine and nucleotide are present. The kinetically determined KI value of approximately 4 muM for the sulfoximine is about three orders of magnitude tighter than thee Km' value of approximately 3 mM for L-glutamate. The previously mentioned dissociation constants obtained by enhancement titrations are also orders of magnitude tighter than Km'. These data suggest that L-methionine (SR)-sulfoximine is a "transition-state" analogue for the glutamine synthetase reaction. ...
journal_name
Biochemistryjournal_title
Biochemistryauthors
Villafranca JJ,Ash DE,Wedler FCdoi
10.1021/bi00648a014subject
Has Abstractpub_date
1976-02-10 00:00:00pages
544-53issue
3eissn
0006-2960issn
1520-4995journal_volume
15pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Horseradish peroxidase C binds a wide variety of small H-donor compounds such as benzohydroxamic acid (BHA) and 2-naphthohydroxamic acid (NHA). In this work, we use the Mg(II)-mesoporphyrin prosthetic group derivative as a spectroscopic probe of the active site and of the interaction with the substrates. We report on ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi002938a
更新日期:2001-08-07 00:00:00
abstract::N-Ethylmaleimide modified heavy meromyosin in only 3-fold activated by actin rather than 200-fold as is normal heavy meromyosin (Silverman, R., Eisenberg, E., and Kielley, W. W. (1972), Nature (London) 240, 207). Ultracentrifuge studies demonstrated that in the absence of ATP the N-ethylmaleimide modified heavy merom...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00688a020
更新日期:1975-08-26 00:00:00
abstract::Human neutrophil cathepsin G or bovine chymotrypsin proteolytically cleaved human alpha-thrombin at the B-chain Trp148-Thr149 bond generating a new form, zeta-thrombin. While incubation of alpha-thrombin with cathepsin G at pH 7.4 and 37 degrees C resulted in a partial loss of fibrinogen clotting activity, 86 +/- 13% ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00466a017
更新日期:1990-04-10 00:00:00
abstract::The hepatitis delta virus (HDV) ribozyme and HDV-like ribozymes are self-cleaving RNAs found throughout all kingdoms of life. These RNAs fold into a double-nested pseudoknot structure and cleave RNA, yielding 2',3'-cyclic phosphate and 5'-hydroxyl termini. The active site nucleotide C75 has a pK(a) shifted >2 pH units...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100670p
更新日期:2010-08-10 00:00:00
abstract::The bidirectional transformation of a protein between its native water-soluble and integral transmembrane conformations is demonstrated for FraC, a hemolytic protein of the family of pore-forming toxins. In the presence of biological membranes, the water-soluble conformation of FraC undergoes a remarkable structural r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01112
更新日期:2015-11-24 00:00:00
abstract::Membranes derived from free floating granulosa cells in porcine ovarian follicular fluid were used as a starting material for structural characterization of both LH/hCG and FSH receptors. The receptors were highly hormone-specific and showed single classes of high-affinity binding sites (Kd = 19-74 pM). Their molecula...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00467a022
更新日期:1990-04-17 00:00:00
abstract::The interaction of the 2'-phosphate-containing nucleotides (NADP+, NADPH, 2'-phosphoadenosine 5'-diphosphoribose, and adenosine 2',5'-bisphosphate) with NADP+ -specific isocitrate dehydrogenase was studied by using 31P NMR spectroscopy. The separate resonances corresponding to free and bound nucleotides, characteristi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00303a015
更新日期:1984-04-10 00:00:00
abstract::The first epidermal growth factor-like domain (EGF-1) from blood coagulation factor VII (FVII) contains two unusual O-linked glycosylation sites at Ser-52 and Ser-60. We report here a detailed study of the effect of O-fucosylation at Ser-60 on the structure of FVII EGF-1, its Ca2+-binding affinity, and its interaction...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990234z
更新日期:1999-06-01 00:00:00
abstract::A double mutant of the single-domain protein barstar having a single tryptophan (W53) was made by mutating the remaining two tryptophans (W38 and W44) into phenylalanines. W53 is buried in the core of barstar. Time-resolved fluorescence of the mutant barstar (W38FW44F) showed that W53 has a single fluorescence lifetim...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9603478
更新日期:1996-07-16 00:00:00
abstract::Reaction center (RC) complexes isolated from a Zn-bacteriochlorophyll (BChl) a-containing purple bacterium, Acidiphilium rubrum, were characterized by absorption, circular dichroism, and magnetic circular dichroism (MCD) spectroscopy. The oxidized-minus-reduced difference spectra indicated that, in this RC, the Zn-BCh...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991444e
更新日期:2000-04-11 00:00:00
abstract::Transported proteins often contain an extension sequence called the signal peptide. The alkaline phosphatase (PhoA) signal sequence represents a typical signal peptide for comparison to idealized sequences both in vivo and in vitro. We have designed a series of idealized signal sequences which vary in amino terminal c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00031a012
更新日期:1995-08-08 00:00:00
abstract::The properties of the Fe and Mo sites of the iron-molybdenum cofactor of nitrogenase with respect to binding and activation of N(2) have been studied by molecular mechanics calculations on the local protein environment and by density functional theory (DFT) calculations on subsections of the cofactor. The DFT calculat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025623z
更新日期:2002-11-26 00:00:00
abstract::Virulent strains of Clostridium sordellii cause gangrenous myonecrosis in humans. The released lethal toxin (TcsL) and hemorrhagic toxin (TcsH) are regarded as the major virulence factors. TcsL inactivates low molecular weight GTP-binding proteins of the Rho/Ras subfamilies by monoglucosylation. In cultured cell lines...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900964c
更新日期:2009-09-29 00:00:00
abstract::The functional role of distinct phospholipid subclasses and molecular species in modulating gramicidin-mediated K+ flux was characterized through quantification of changes in the fluorescence intensity of ion specific fluorescent probes encapsulated inside vesicles comprised of individual molecular species of plasmeny...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00022a008
更新日期:1995-06-06 00:00:00
abstract::We have developed a homogeneous time-resolved fluorescence resonance energy transfer (FRET)-based assay that detects the formation of HIV-1 integrase (IN) dimers. The assay utilizes IN monomers that express two different epitope tags that are recognized by their respective antibodies, coupled to distinct fluorophores....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101504w
更新日期:2011-03-15 00:00:00
abstract::The fidelity of the poliovirus RNA-dependent RNA polymerase (3D(pol)) plays a direct role in the genomic evolution and pathogenesis of the virus. A single site mutation (Gly64Ser) that is remote from the catalytic center results in a higher fidelity polymerase. NMR studies with [methyl-(13)C]methionine-labeled protein...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100833r
更新日期:2010-11-02 00:00:00
abstract::We have examined the conformational behavior under various unfolding conditions of a predominantly beta-sheet protein, cellular retinoic acid binding protein (CRABP). Urea unfolding-refolding of CRABP is a highly cooperative process that can be approximated by a two-state model. Acid denaturation is also cooperative a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00167a017
更新日期:1994-01-11 00:00:00
abstract::Structures of several voltage-gated sodium (NaV) channels from bacteria have been determined recently, but the same feat might not be achieved for the mammalian counterparts in the near future. Thus, at present, computational studies of the mammalian NaV channels have to be performed using homology models based on the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01324
更新日期:2016-03-29 00:00:00
abstract::Different sites of the tRNA molecule influence the activity of the elongation factor Tu (EF-Tu) center for GTP hydrolysis [Parlato, G., Pizzano, R., Picone, D., Guesnet, J., Fasano, O., & Parmeggiani, A. (1983) J. Biol. Chem. 258, 995-1000]. Continuing these studies, we have investigated some aspects of (a) the effect...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00427a044
更新日期:1989-01-10 00:00:00
abstract::Temperature-jump experiments were performed with di-, tetra-, and hexasaccharides derived from type III pneumococcal polysaccharide using a homogeneous corresponding antibody IgG 45-394. A decrease in stability of the oligosaccharide-antibody complexes with decreasing chain length was observed and entirely reflected i...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00637a023
更新日期:1977-09-06 00:00:00
abstract::Solid-state NMR spectroscopy was employed to study the molecular dynamics of the colicin Ia channel domain in the soluble and membrane-bound states. In the soluble state, the protein executes small-amplitude librations (with root-mean-square angular fluctuations of 0-10 degrees ) in the backbone and larger-amplitude m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0027231
更新日期:2001-06-26 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::Human telomeres are comprised of d(TTAGGG) repeats that are capable of forming G-quadruplex DNA structures. Ligands that bind to and stabilize these G-quadruplex DNA structures are potential inhibitors of the cancer cell-associated enzyme telomerase. Other potential biological uses of G-quadruplex targeting ligands ha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0263107
更新日期:2002-09-24 00:00:00
abstract::13C NMR has been used to demonstrate the metabolism of dilute solutions of labeled formaldehyde by Escherichia coli to methanol, formate, carbon dioxide, and several other unidentified metabolites which contain labeled CH2 groups. Aeration of bacterial suspensions within the spectrometer dramatically increased the rat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00298a017
更新日期:1984-01-31 00:00:00
abstract::We constructed and expressed chimeric receptor cDNAs with insulin receptor exon 3 (residues 191-297 of the cysteine-rich region) replaced with either the comparable region of the insulin-like growth factor I receptor (IGF-IR) or the insulin receptor related receptor (IRR). Both chimeric receptors still could bind insu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00235a001
更新日期:1991-05-28 00:00:00
abstract::The molecular mechanism for the displacement of HMGA1 proteins from DNA is integral to disrupting their cellular function, which is linked to many metastatic cancers. Chemical shift and NOESY NMR experiments provide structural evidence for the displacement of an AT hook peptide (DNA binding motif of HMGA1 proteins) by...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200822c
更新日期:2011-09-27 00:00:00
abstract::The relationship between triacylglycerol and monoacylglycerol hydrolyzing activities of purified rat heart lipoprotein lipase was studied using emulsified trioleoylglycerol and micellar or albumin-bound monooleoylglycerol as substrates. The maximal reaction rates obtained with the two substrates were similar (650 and ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00654a017
更新日期:1976-05-04 00:00:00
abstract::The molecular mechanism of O2 binding to hemoglobin (Hb) and myoglobin (Mb) is a long-standing issue in the field of bioinorganic and biophysical chemistry. The nature of Fe-O2 bond in oxy Hb and Mb had been extensively investigated by resonance Raman spectroscopy, which assigned the Fe-O2 stretching bands at ∼570 cm-...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00829
更新日期:2018-12-04 00:00:00
abstract::Homeodomain-only protein (HOP) is an 8-kDa transcriptional corepressor that is essential for the normal development of the mammalian heart. Previous studies have shown that HOP, which consists entirely of a putative homeodomain, acts downstream of Nkx2.5 and associates with the serum response factor (SRF), repressing ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060641s
更新日期:2006-09-05 00:00:00
abstract::The enzyme PvdQ (E.C. 3.5.1.97) from Pseudomonas aeruginosa is an N-terminal nucleophile hydrolase that catalyzes the removal of an N-myristyl substituent from a biosynthetic precursor of the iron-chelating siderophore pyoverdine. Inhibitors of pyoverdine biosynthesis are potential antibiotics since iron is essential ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi501086s
更新日期:2014-10-28 00:00:00