Abstract:
:We have visualized by freeze-etch electron microscopy the macromolecular complexes of complement, C5b-8 and C5b-9, respectively, assembled on synthetic phospholipid bilayers. These complexes were formed sequentially by using purified human complement components C5b-6 followed by C7, C8, and C9. Complexes of C5b-8 were observed on the external surface (ES) of vesicles as 12-nm particles that tended to form polydisperse aggregates. The aggregates were sometimes of a regular chainlike structure containing varying numbers of paired subunits. Etching of vesicles containing C5b-9 complexes revealed on the ES large rings of approximately 27-nm outer diameter. One or two knobs usually were attached to the perimeter of the rings. Splitting of the membrane resulted in partitioning of the C5b-9 with the outer leaflet. Thus, round holes of approximately 17-nm diameter were present in the protoplasmic face (PF), and raised circular stumps of a matching size were present on the exoplasmic face (EF) of C5b-9 vesicles. C5b-9 complexes were frequently localized in regions of the lowest lipid order. That is, in micrographs of the EF and ES, single C5b-9 complexes were located where the ripples of the P beta' phase bend or reach a dead end, and linear arrays of C5b-9 complexes outlined disclination-like structures in the lattice; the holes in the PF mirrored this distribution. The membrane immediately surrounding C5b-9 rings was often sunk inwardly over an area much larger than that of the ring itself.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
McCloskey MA,Dankert JR,Esser AFdoi
10.1021/bi00428a019subject
Has Abstractpub_date
1989-01-24 00:00:00pages
534-40issue
2eissn
0006-2960issn
1520-4995journal_volume
28pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The soluble domains of the b and b' subunits of the ATP synthase of the cyanobacterium Synechocystis PCC 6803 were expressed with His tags attached to their N-termini. Following purification, the polypeptides were characterized by chemical cross-linking, analytical ultracentrifugation, and circular dichroism spectrosc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001821j
更新日期:2001-01-09 00:00:00
abstract::The Radical SAM (RS) enzyme PqqE catalyzes the first step in the biosynthesis of the bacterial cofactor pyrroloquinoline quinone, forming a new carbon-carbon bond between two side chains within the ribosomally synthesized peptide substrate PqqA. In addition to the active site RS 4Fe-4S cluster, PqqE is predicted to ha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b01097
更新日期:2018-02-27 00:00:00
abstract::Photoreceptor guanylyl cyclase (ROS-GC), converting GTP into cGMP and pyrophosphate, is a key enzyme in the regulation of the visual transduction cascade. ROS-GC requires GC-activating proteins (GCAPs) and low free [Ca] for full activity. We found that when choline or potassium were the major cations present, light ca...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9825596
更新日期:1999-03-02 00:00:00
abstract::S-Adenosylmethionine decarboxylase is a pyruvate-dependent enzyme. The enzyme forms a Schiff base with substrate, S-adenosylmethionine, through the pyruvoyl moiety. This facilitates the release of CO2 from the substrate, which must then be protonated on the alpha carbon in order to permit hydrolysis of the Schiff base...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9825201
更新日期:1999-02-23 00:00:00
abstract::Translation of mRNAs by the ribosome is stereospecific, with only l-amino acids being incorporated into the nascent polypeptide chain. This stereospecificity results from the exclusion of d-amino acids at three steps during protein synthesis: (1) the aminoacylation of tRNA by aminoacyl-tRNA synthetases, (2) binding of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01167
更新日期:2016-03-15 00:00:00
abstract::The cooperative binding of the Escherichia coli DNA unwinding protein to single-stranded DNA has been studied by electron microscopy. Analysis of the electron microscopic data by means of a simple statistical mechanical model has yielded a value of 3.8-7.6 X 10(10) l./mol for the cooperative binding constant in 0.15 M...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00696a023
更新日期:1975-12-16 00:00:00
abstract::Fourier transform infrared (FTIR) spectroscopy was applied to the blue-light photoreceptor photoactive yellow protein (PYP) to investigate water structural changes possibly involved in the photocycle of PYP. Photointermediates were stabilized at low temperature, and difference IR spectra were obtained between intermed...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi000357f
更新日期:2000-07-11 00:00:00
abstract::The Met16Phe mutant of the type 1 copper protein pseudoazurin (PACu), in which a phenyl ring is introduced close to the imidazole moiety of the His81 ligand, has been characterized. NMR studies indicate that the introduced phenyl ring is parallel to the imidazole group of His81. The mutation has a subtle effect on the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi030030p
更新日期:2003-06-10 00:00:00
abstract::Aldehyde dehydrogenase 7A1 (ALDH7A1) is part of lysine catabolism and catalyzes the NAD(+)-dependent oxidation of α-aminoadipate semialdehyde to α-aminoadipate. Herein, we describe a structural study of human ALDH7A1 focused on substrate recognition. Five crystal structures and small-angle X-ray scattering data are re...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00754
更新日期:2015-09-08 00:00:00
abstract::Pig liver phosphomevalonate kinase (EC 2.7.4.2) has been purified to homogeneity as shown by polyacrylamide gel electrophoresis. The molecular weight estimates range from 21,000 to 22,500. Each molecule is composed of one polypeptide chain. The presence of SH-containing reagents is essential for the preservation of en...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00552a003
更新日期:1980-05-27 00:00:00
abstract::Clostridial neurotoxins are zinc endopeptidases, and each contains one Zn(2+)/molecule. To investigate the structural/functional role of Zn(2+) in botulinum neurotoxin light chain (the enzymatic subunit of the neurotoxin), the effect of the removal of zinc on protein folding and enzyme kinetics was investigated. The a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0007472
更新日期:2000-08-29 00:00:00
abstract::The biochemical and structural properties of bovine retinal nucleoside diphosphate kinase were investigated. The enzyme showed two polypeptides of approximately 17.5 and 18.5 kDa on SDS-PAGE, while isoelectric focusing revealed seven to eight proteins with a pI range of 7.4-8.2. Sedimentation equilibrium yielded a mol...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980853s
更新日期:1998-10-06 00:00:00
abstract::Peptide nucleic acids (PNAs) are nonionic DNA/RNA mimics that can recognize complementary sequences by Watson-Crick base pairing. The neutral PNA backbone facilitates the recognition of duplex DNA by strand invasion, suggesting that antigene PNAs (agPNAs) can be important tools for exploring the structure and function...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700230a
更新日期:2007-06-26 00:00:00
abstract::The initiation of Escherichia coli chromosomal replication by DnaA protein is strongly influenced by the tight binding of the nucleotides ATP and ADP. Anionic phospholipids in a fluid bilayer promote the conversion of inactive ADP-DnaA protein to replicatively active ATP-DnaA protein in vitro, and thus likely play a k...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982733q
更新日期:1999-05-11 00:00:00
abstract::The DNA binding of three platinum(II) intercalation reagents has been studied and found to depend upon base composition, the nature of the intercalator, and the ionic strength of the solvent medium. In 0.2 M NaCl, binding data for calf thymus DNA show the association constants to be approximately 10(4) M-1. The bindin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00593a003
更新日期:1979-12-25 00:00:00
abstract::Gap junctions, transmembrane protein channels that directly connect the cytoplasm of neighboring cells and enable the exchange of molecules between cells, are a promising new frontier for therapeutic delivery. Specifically, cell-derived lipid vesicles that contain functional gap junction channels, termed Connectosomes...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00688
更新日期:2018-01-09 00:00:00
abstract::SH2 domain-containing inositol 5-phosphatases 1 (SHIP1) and 2 (SHIP2) are structurally similar proteins that catalyze the degradation of lipid secondary messenger phosphatidylinositol 3,4,5-triphosphate to produce phosphatidylinositol 3,4-diphosphate. Despite their high sequence identity (51%), SHIP1 and SHIP2 share l...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9012462
更新日期:2009-11-24 00:00:00
abstract::cis peptide bonds in proteins are often rate-limiting steps in protein folding or conformational change and are frequently stabilized by metal ions. In the collagen-binding domain of Clostridium histolyticum collagenase, the binding of calcium ions triggers the formation of a cis peptide bond. We present free energy s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1007047
更新日期:2010-06-29 00:00:00
abstract::Several polypeptide toxins from sea anemones caused delayed inactivation of mammalian voltage-dependent sodium channels, resulting in a positive inotropic effect on the heart. Anthopleurin B (ApB), a toxin produced by the sea anemone Anthopleura xanthogrammica, is the most potent of all known anemone toxins. Previous ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9528457
更新日期:1996-03-19 00:00:00
abstract::Aminoacylation of a transfer RNA (tRNA) by its cognate aminoacyl-tRNA synthetase relies upon the recognition of specific nucleotides as well as conformational features within the tRNA by the synthetase. In Escherichia coli, the aminoacylation of tRNA(His) by histidyl-tRNA synthetase (HisRS) is highly dependent upon th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035708f
更新日期:2004-02-03 00:00:00
abstract::Vibrational Raman spectroscopic experiments have been performed as a function of temperature on aqueous dispersions of synthetic DL-erythro-N-lignoceroylsphingosylphosphocholine [C(24):SPM], a racemic mixture of two highly asymmetric hydrocarbon chain length sphingomyelins. Raman spectral peak-height intensity ratios ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00343a036
更新日期:1985-10-22 00:00:00
abstract::The high molecular weight folate binding protein of rat liver cytosol has been purified to apparent homogeneity. Purification was achieved by using a combination of gel filtration, O-(diethylaminoethyl)cellulose chromatography, and affinity chromatography. This folate binding protein was initially identified during pu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00261a036
更新日期:1982-08-31 00:00:00
abstract::A nucleoside triphosphate binding site on calf thymus RNA polymerase II was identified by using photoaffinity analogues of adenosine 5'-triphosphate and guanosine 5'-triphosphate. Both radiolabeled 8-azidoadenosine 5'-triphosphate (8-N3ATP) and radiolabeled 8-azidoguanosine 5'-triphosphate (8-N3GTP) bound to a single ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00349a038
更新日期:1986-01-14 00:00:00
abstract::The requirement for Ca2+ in the Mn(2+)-dependent photoactivation of oxygen evolution was re-evaluated using 17 kDa/24 kDa-less photosystem II (PSII) membranes depleted of (Mn)4-clusters by NH2OH extraction. At optimum conditions (1 mM Mn2+/10 microM 2,6-dichlorphenolindophenol (DCIP)/20 mM Ca2+), the light-induced inc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00041a031
更新日期:1995-10-17 00:00:00
abstract::We have examined the structure of newly repaired regions of chromatin in intact and permeabilized human cells following exposure to bleomycin (BLM). The average repair patch size (in permeabilized cells) was six to nine bases, following doses of 1-25 micrograms/mL BLM, and greater than 80% of the total repair synthesi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00484a020
更新日期:1990-08-14 00:00:00
abstract::The specificity of valyl-, phenylalanyl-, and tyrosyl-tRNA synthetases from yeast has been examined by a series of stringent tests designed to eliminate the possibility of artefactual interference. Valyl-tRNA synthetase, as well as activating a number of amino acid analogues, will accept alanine, cysteine, isoleucine,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00610a006
更新日期:1978-08-22 00:00:00
abstract::A procedure for the preparation of coupling factor 1 (F1) from Escherichia coli lacking subunits delta and epsilon is described. Using chloroform and dimethyl sulfoxide, we can isolate F1 containing only subunits alpha, beta, and gamma [F1(alpha beta gamma)] directly from membrane vesicles in 10-mg quantities. Pure an...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00438a030
更新日期:1989-06-13 00:00:00
abstract::Betaine-homocysteine S-methyltransferase (BHMT) is a zinc-dependent enzyme that catalyzes the transfer of a methyl group from glycine betaine (Bet) to homocysteine (Hcy) to form dimethylglycine (DMG) and methionine (Met). Previous studies in other laboratories have indicated that catalysis proceeds through the formati...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049821x
更新日期:2004-05-11 00:00:00
abstract::A newly reported strain of Vibrio cholerae, known as strain O139 Bengal, is the first instance of an encapsulated strain that has caused epidemic cholera. The O-antigenic capsule is the critical antigen for protective immunity. Since mapping of the antigenic epitopes will assist in the development of a protein conjuga...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9910272
更新日期:1999-09-14 00:00:00
abstract::The respiratory nitric oxide reductase (NOR) from Paracoccus denitrificans catalyzes the two-electron reduction of NO to N(2)O (2NO + 2H(+) + 2e(-) --> N(2)O + H(2)O), which is an obligatory step in the sequential reduction of nitrate to dinitrogen known as denitrification. NOR has four redox-active cofactors, namely,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi050524h
更新日期:2005-08-09 00:00:00