Abstract:
:Influenza virus gains access to the cytoplasm of its host cell by means of a fusion event between viral and host cell membrane. Fusion is mediated by the envelope glycoprotein hemagglutinin (HA) and is triggered by low pH. To learn how many hemagglutinin trimers are necessary to cause membrane fusion, we have used two NIH 3T3 fibroblast cell lines that express HA protein at different surface densities. On the basis of quantitations of the number of HA trimers per cell and the relative surface areas of the two cell lines, the HAb-2 cells have a 1.9-fold higher plasma membrane surface density than the GP4F cells. The membrane lateral diffusion coefficient and the mobile fraction for HA is the same for both cell lines. A Scatchard analysis of the binding of glycophorin-bearing liposomes to the cells showed 1700 binding sites for the GP4F cells and 3750 binding sites for the HAb-2 cells, with effectively the same liposome-cell binding constant, about 7 x 10(10) M-1. Binding was specific for glycophorin on the liposomes and HA expressed on the cells. A competition experiment employing toxin-containing and empty liposomes allowed us to quantitate the number of liposomes that fused per cell, which was a small constant fraction of the number of bound liposomes. For the HAb-2 cells, about 1 in every 70 bound liposomes fused and for the GP4F cells about 1 in every 300 bound liposomes fused. Hence, the HAb-2 cells showed 4.4 times more fusion per bound liposome, even though the surface density of HA was only 1.9 times greater. We conclude the following: (i) One HA trimer is not sufficient to induce fusion. (ii) The HA bound to glycophorin is not the HA that induces fusion. That is, even though each HA has a binding and a fusion function, those functions are not performed by the same HA trimer.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Ellens H,Bentz J,Mason D,Zhang F,White JMdoi
10.1021/bi00493a027subject
Has Abstractpub_date
1990-10-16 00:00:00pages
9697-707issue
41eissn
0006-2960issn
1520-4995journal_volume
29pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::We have investigated the kinetic and thermodynamic properties of carbon monoxide binding to the fully reduced quinol oxidase (cytochrome aa(3)) from the hyperthermophilic archaeon Acidianus ambivalens. After flash photolysis of CO from heme a(3), the complex recombines with an apparent rate constant of approximately 3...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990473m
更新日期:1999-08-03 00:00:00
abstract::By classical competitive antagonism, a substrate and competitive inhibitor must bind mutually exclusively to the active site. The competitive inhibition of O-acetyl serine sulfhydrylase (OASS) by the C-terminus of serine acetyltransferase (SAT) presents a paradox, because the C-terminus of SAT binds to the active site...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00500
更新日期:2017-09-19 00:00:00
abstract::Escherichia coli (A)BC excinuclease is the major enzyme responsible for removing bulky adducts, such as pyrimidine dimers and 6-4 photoproducts, from DNA. Mutants deficient in this enzyme are extremely sensitive to UV and UV-mimetic agents, but not to oxidizing agents, or ionizing radiation which damages DNA in part b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00446a002
更新日期:1989-10-03 00:00:00
abstract::GxTX-1E is a neurotoxin recently isolated from Plesiophrictus guangxiensis venom that inhibits the Kv2.1 channel in pancreatic beta-cells. The sequence of the toxin is related to those of previously studied tarantula toxins that interact with the voltage sensors in Kv channels, and GxTX-1E interacts with the Kv2.1 cha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100246u
更新日期:2010-06-29 00:00:00
abstract::The protein phosphatase 2C (PP2C) family represents one of the four major protein Ser/Thr phosphatase activities in mammalian cells and contains at least 13 distinct gene products. Although PP2C family members regulate a variety of cellular functions, mechanisms of regulation of their activities are largely unknown. H...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi800067p
更新日期:2008-07-08 00:00:00
abstract::The nonbulky 5',8-cyclopurine DNA lesions (cP) and the bulky, benzo[ a]pyrene diol epoxide-derived stereoisomeric cis- and trans- N2-guanine adducts (BPDE-dG) are good substrates of the human nucleotide excision repair (NER) mechanism. These DNA lesions were embedded at the In or Out rotational settings near the dyad ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b01066
更新日期:2019-02-12 00:00:00
abstract::Minor adducts, derived from the covalent binding of anti-benzo[a]pyrene-7,8-dihydroxy-9,10-epoxide to cellular DNA, may play an important role in generating mutations and initiating cancer. We have applied a combined NMR-computational approach including intensity based refinement to determine the solution structure of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991212f
更新日期:1999-08-17 00:00:00
abstract::Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimicked by subfragments of the protein, including the C-terminus. We have...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0481895
更新日期:2004-12-07 00:00:00
abstract::The processes of liposome solubilization and reconstitution were studied by using n-dodecyl octaethylene glycol monoether (C12E8). The solubilization of large unilamellar liposomes prepared by reverse-phase evaporation was systematically investigated by turbidity, 31P nuclear magnetic resonance, and centrifugation exp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00492a022
更新日期:1990-10-09 00:00:00
abstract::Using solution peptide synthesis, we have made three series of N alpha-formylated homooligopeptides, from the dipeptide to the heptapeptide, derived from L-methionine, L-norleucine, and S-methyl-L-cysteine and related to the chemotactic peptide N alpha-formylmethionylleucylphenylalanine. Compounds were prepared to det...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00299a018
更新日期:1984-02-14 00:00:00
abstract::A dark state tertiary structure in the cytoplasmic domain of rhodopsin is presumed to be the key to the restriction of binding of transducin and rhodopsin kinase to rhodopsin. Upon light-activation, this tertiary structure undergoes a conformational change to form a new structure, which is recognized by the above prot...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi010746p
更新日期:2001-10-23 00:00:00
abstract::The subgel phases of a homologous series of saturated straight-chain diacylphosphatidylcholines with hydrocarbon chains consisting of 10-18 carbon atoms were studied by Fourier-transform infrared spectroscopy. All of these lipids initially form a subgel phase which is spectroscopically similar to that obtained when fu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00486a024
更新日期:1990-08-28 00:00:00
abstract::The insulin-like growth factor-II/mannose 6-phosphate receptor (IGF-II/MPR) is a type I glycoprotein that mediates both the intracellular sorting of lysosomal enzymes bearing mannose 6-phosphate (Man-6-P) residues to the lysosome and the bioavailability of IGF-II. The extracytoplasmic region of the IGF-II/MPR contains...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992226o
更新日期:2000-03-07 00:00:00
abstract::Anatoxin-a and homoanatoxin-a are two potent cyanobacterial neurotoxins. We recently reported the identification of the gene cluster responsible for the biosynthesis of these toxins as well as the in-vitro reconstitution of the first steps of this biosynthesis. We now report experimental evidence supporting the propos...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200892a
更新日期:2011-08-23 00:00:00
abstract::Previous work has indicated that PEP mutase catalyzes the rearrangement of phosphoenolpyruvate to phosphonopyruvate by a dissociative mechanism. The crystal structure of the mutase with Mg(II) and sulfopyruvate (a phosphonopyruvate analogue) bound showed that the substrate is anchored to the active site by the Mg(II),...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi036255h
更新日期:2004-04-20 00:00:00
abstract::Molecular cloning revealed the unique serpin endopin 2C that demonstrates selective inhibition of cathepsin L compared to papain or elastase. Endopin 2C, thus, functions as a serpin with the property of cross-class inhibition. Endopin 2C possesses homology in primary sequence to endopin 2A and other isoforms of endopi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi050053z
更新日期:2005-05-31 00:00:00
abstract::Although plasma membrane domains, such as caveolae, provide an organizing principle for signaling pathways and cholesterol homeostasis in the cell, relatively little is known regarding specific mechanisms, whereby intracellular lipid-binding proteins are targeted to caveolae. Therefore, the interaction between caveoli...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7002636
更新日期:2007-07-17 00:00:00
abstract::alpha5beta1 integrin can occupy several distinct conformational states which support different strengths of binding to fibronectin [García, A. J., et al. (1998) J. Biol. Chem. 273, 34710-34715]. Using a model system in which specific activating monoclonal antibodies were used to achieve uniform activated states, the b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025752f
更新日期:2002-07-23 00:00:00
abstract::The X-ray structures of neuronal nitric oxide synthase (nNOS) with N(omega)-hydroxy-l-arginine (l-NHA) and CO (or NO) bound have been determined at 1.91-2.2 A resolution. Microspectrophotometric techniques confirmed reduced redox state and the status of diatomic ligand complexes during X-ray diffraction data collectio...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9009743
更新日期:2009-11-03 00:00:00
abstract::Nitric oxide (NO) regulates cardiovascular hemostasis by binding to soluble guanylyl cyclase (sGC), leading to cGMP production, reduced cytosolic calcium concentration ([Ca(2+)](i)), and vasorelaxation. Thrombospondin-1 (TSP-1), a secreted matricellular protein, was recently discovered to inhibit NO signaling and sGC ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi201060c
更新日期:2011-09-13 00:00:00
abstract::The Ndi1 enzyme found in the mitochondrial membrane of Saccharomyces cerevisiae is an NDH-2-type alternative NADH-quinone oxidoreductase. As Ndi1 is expected to be a possible remedy for complex I defects of mammalian mitochondria, a detailed biochemical characterization of the enzyme is needed. To identify the ubiquin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100005j
更新日期:2010-04-06 00:00:00
abstract::The c-Jun N-terminal kinases (JNKs) play a wide variety of roles in cellular signaling processes, dictating important, and even divergent, cellular fates. These essential kinases possess docking surfaces distal to their active sites that interact with diverse binding partners, including upstream activators, downstream...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00776
更新日期:2018-10-09 00:00:00
abstract::Most A/T specific heterocyclic diamidine derivatives need at least four A/T base pairs for tight binding to the DNA minor groove. Addition of a GC base pair to A/T sequences typically causes a large decrease in binding constant. The ability to target biologically important sequences of DNA could be significantly incre...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801944g
更新日期:2009-02-24 00:00:00
abstract::The effect of anions on the stability of different functional conformations of Hb is examined through the determination of the dependence of O(2) affinity on water activity (a(w)). The control of a(w) is effected by varying the sucrose osmolal concentration in the bathing solution according to the "osmotic stress" met...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9905361
更新日期:1999-09-07 00:00:00
abstract::Nephrocalcin (NC), a calcium-binding glycoprotein of 14,000 molecular weight as a monomer, is known to inhibit the growth of calcium oxalate monohydrate (COM) crystals in renal tubules. We have isolated NC from bovine kidney tissue and purified into four isoforms, fractions A-D. NC-A and NC-B strongly inhibit the grow...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961200j
更新日期:1996-11-26 00:00:00
abstract::TcmO is an O-methyltransferase that methylates the C-8 hydroxyl to Tcm B3, a four-ring aromatic intermediate in the tetracenomycin biosynthetic pathway of Streptomyces glaucescens. The gene encoding this enzyme was expressed in Streptomyces coelicolor CH999 together with the actinorhodin polyketide synthase (PKS) gene...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi952957y
更新日期:1996-05-28 00:00:00
abstract::The murine invariant chain (Ii) was found to incorporate radioactive palmitic acid. This binding of fatty acid inhibits the formation of interchain S-S bonds, probably because the cysteine residue in the transmembrane region of the Ii chain is palmitylated. The inhibition of fatty acylation by cerulenin blocks further...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00343a023
更新日期:1985-10-22 00:00:00
abstract::Homology modeling was used to identify two particular residues, Glu175 and Ala176, in Pseudomonas stutzeri phosphite dehydrogenase (PTDH) as the principal determinants of nicotinamide cofactor (NAD(+) and NADP(+)) specificity. Replacement of these two residues by site-directed mutagenesis with Ala175 and Arg176 both s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035018b
更新日期:2003-10-14 00:00:00
abstract::In this paper, we report kinetic studies for the chymotryptic activity of the 20S proteasome. Major observations include the following: (1) Reaction progress curves that are recorded at concentrations of Suc-Leu-Leu-Val-Tyr-AMC greater than about 40 microM are biphasic and characterized by initial velocities that deca...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi952262x
更新日期:1996-04-02 00:00:00
abstract::The DNA strand cleavage reaction catalyzed by endonuclease III from Escherichia coli (endo III) on the 3'-side of aldehyde abasic sites proceeds by a syn beta-elimination involving abstraction of the 2'-pro-S proton and formation of a trans alpha,beta-unsaturated aldose product; we previously reported the same stereoc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00218a033
更新日期:1991-01-29 00:00:00