Abstract:
:A fluorescence quenching method was developed for determining partition coefficients and diffusional rates of small molecules in cell membranes. This method involves quenching the fluorescence of carbazole-labeled membranes by hydrophobic molecules that partition into membranes. Cell membrane phospholipids of mouse LM cells in tissue culture were biosynthetically labeled with the carbazole moiety by supplementing the growth media with 11-(9-carbazolyl)undecanoic acid. Plasma membranes, microsomes, and mitochondria were isolated free of nonmembranous neutral lipids, and the incorporation of the fluorescent probe was characterized. Quenching studies of the carbazole moiety by a series of N-substituted picolinium perchlorate salts showed that the carbazole moiety was located in the hydrophobic interior of the membrane bilayer. The carbazole fluorescence also was quenched by the hydrophobic quenchers lindane, methoxychlor, and 1,1-dichloro-2,2-bis(rho-chlorophenyl)ethylene, indicating that these compounds partitioned into the membrane. Stern-Volmer quenching constants determined by fluorescence lifetime and intensity measurements were identical, as expected for dynamic quenching. The effects of different lipid compositions on quenching constants and partition coefficients were determined by comparing different membrane fractions. These parameters also were measured in membranes from cells in which the phospholipid composition was altered by substituting ethanolamine for choline in the growth medium. Changes in the lipid composition produced changes in the bimolecular quenching constants. For example, bimolecular quenching constants for 1,1-dichloro-2,2-bis(rho-chlorophenyl)ethylene were higher in mitochondrial membranes than in plasma membranes and microsomes. They were also higher in dispersions made from membrane phospholipids as compared with intact membranes or total lipid dispersion.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Omann GM,Glaser Mdoi
10.1021/bi00316a021subject
Has Abstractpub_date
1984-10-09 00:00:00pages
4962-9issue
21eissn
0006-2960issn
1520-4995journal_volume
23pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::There is considerable evidence that mammalian beta-tubulin is phosphorylated. Specifically, of the seven beta isotypes, the phosphorylated one is beta III, the isotype found almost entirely in neurons. The phosphate is added at a serine and perhaps a tyrosine near the C-terminus. All the evidence to date has been gath...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi951247p
更新日期:1996-03-26 00:00:00
abstract::The mammalian iron-binding proteins lactoferrin (Lf) and transferrin (Tf) bind iron very tightly, but reversibly. Despite homologous structures and essentially identical iron binding sites, Tf begins to release iron at pH 6.0, whereas Lf retains iron to pH approximately 3.5. This difference in iron retention gives the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi020443a
更新日期:2002-12-03 00:00:00
abstract::Cardiac troponin T (cTnT) is a myofibrillar protein essential for calcium-dependent contraction. This property has led to functional studies of developmentally expressed cTnT isoforms and mutants identified in patients with hypertrophic cardiomyopathy. The release of cTnT into the serum following myocardial infarction...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7012596
更新日期:2008-02-19 00:00:00
abstract::Fusion of a prokaryotic promoter to a yeast tRNA gene provides a means for uncoupling analyses of mutations affecting splicing from requirements for transcription and other processing steps. For this purpose, a phage lambda promoter was fused to the Saccharomyces cerevisiae tRNATyr(SUP3a) coding sequence. This fusion ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00240a017
更新日期:1991-07-02 00:00:00
abstract::Distinct structural features of DNA, such as the curvature of dA tracts, are important in the recognition, packaging, and regulation of DNA. Physiologically relevant concentrations of magnesium have been found to enhance the curvature of dA tract DNAs, as monitored by solution-state NMR, indicating that the structure ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi010853j
更新日期:2001-08-07 00:00:00
abstract::The malaria parasite pigment, hemozoin, is a crystal of ferriprotoporphyrin IX (FP-Fe(III)), a product of hemoglobin digestion. Hemozoin formation is essential for FP-Fe(III) detoxification in the parasite; it is the main target of quinoline antimalarials and can modulate immune and inflammation responses. To gain fur...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100567j
更新日期:2010-08-10 00:00:00
abstract::Bean-deleterious Pseudomonas A214 produced the extracellular yellow-green, fluorescent siderophore [microbial iron(III) transport agent] pseudobactin A214 under iron-limiting conditions. Pseudobactin A214 has a molecular formula of C46H64N13O22 and a molecular mass of 1151 g/mol. Pseudobactin A214 contained an N-block...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00367a022
更新日期:1986-09-23 00:00:00
abstract::The GTP-binding proteins or GTPases comprise a superfamily of proteins that provide molecular switches in numerous cellular processes. The "GTPase switch" paradigm, in which a GTPase acts as a bimodal switch that is turned "on" and "off" by external regulatory factors, has been used to interpret the regulatory mechani...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9006989
更新日期:2009-07-28 00:00:00
abstract::X-ray crystallographic studies have shown that DNA binding by human polymerase beta (pol beta) occurs primarily through two structurally and sequentially homologous helix-hairpin-helix (HhH) motifs, one in the fingers subdomain and the other in the 8-kDa domain [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H.,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi960790i
更新日期:1996-10-01 00:00:00
abstract::Single lamellar phosphatidyl[methyl-2H]choline vesicles were incubated with an excess of unlabeled phosphatidylcholine vesicles or phosphatidylcholine-cholesterol vesicles containing 8 mol % glucuronosyldiglyceride. Incubation of the two vesicle populations was performed in the presence or absence of a purified phosph...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00534a017
更新日期:1982-03-02 00:00:00
abstract::Interconversion of protein conformations is imperative to function, as evidenced by conformational changes associated with enzyme catalytic cycles, ligand binding and post-translational modifications. In this study, we used 15N NMR relaxation experiments to probe the fast (i.e., ps-ns) and slow (i.e., micros-ms) confo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701425n
更新日期:2007-12-25 00:00:00
abstract::The human endonuclease III (hNTH1) is an important DNA glycosylase with associated abasic lyase activity. We previously demonstrated that the K212Q mutant was totally inactive, while the K212R mutant had reduced DNA glycosylase/lyase activity and could form a covalent complex with the substrate DNA upon reduction. We ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011053b
更新日期:2001-11-13 00:00:00
abstract::DNA three-way junctions (3WJs) are branched structures that serve as important biological intermediates and as components in DNA nanostructures. We recently derived the global structure of a fully complementary 3WJ and found that it contained unpaired bases at the branchpoint, which is consistent with previous observa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00677
更新日期:2017-09-19 00:00:00
abstract::Azurin from Pseudomonas aeruginosa and two mutants where the methionine ligand has been mutated have been studied in order to directly investigate the functional and structural significance of this ligand in the blue copper proteins. Reduction potentials, X-ray absorption fine structure (XAFS), electron paramagnetic r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00059a013
更新日期:1993-03-02 00:00:00
abstract::Antithrombin III (ATIII) is a plasma-borne serine protease inhibitor that apparently forms covalent complexes with thrombin. The interaction between ATIII and thrombin is enhanced several thousandfold by the glycosaminoglycan, heparin. We have previously proposed that the heparin binding site of ATIII resides within a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00490a010
更新日期:1990-09-25 00:00:00
abstract::CopA, a thermophilic membrane ATPase from Archaeoglobus fulgidus, drives the outward movement of Cu(+) or Ag(+) [Mandal et al. (2002) J. Biol. Chem. 277, 7201-7208]. This, as other P(IB)-ATPases, is characterized by a putative metal binding sequence (C(380)PC(382)) in its sixth transmembrane fragment and cytoplasmic m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034806y
更新日期:2003-09-23 00:00:00
abstract::It is known that the proapoptotic protein Bax facilitates the formation of pores in bilayers, resulting in the release of proteins from the intermitochondrial space. We demonstrate that another consequence of the interaction of Bax with membranes is an increase in the rate of lipid transbilayer diffusion. We use two i...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035348w
更新日期:2003-12-16 00:00:00
abstract::The incorporation of extensively fluorinated, or fluorous, analogues of hydrophobic amino acids into proteins potentially provides the opportunity to modulate the physicochemical properties of proteins in a predictable manner. On the basis of the properties of small fluorocarbon molecules, extensively fluorinated prot...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901481k
更新日期:2009-11-17 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::Recent evidence adds support to a traditional concept according to which the eukaryotic nucleus is organized into functional domains by scaffold or matrix attachment regions (S/MARs). These regions have previously been predicted to have a high potential for stress-induced duplex destabilization (SIDD). Here we report ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026496+
更新日期:2003-01-14 00:00:00
abstract::Applications of sensitive new technologies, in particular, two-dimensional NMR spectroscopy, have allowed detection of folded structures in short peptide fragments of proteins in aqueous solution under conditions where native proteins fold. These structures are in rapid dynamic exchange with unfolded states. These obs...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi00419a001
更新日期:1988-09-20 00:00:00
abstract::Sorcin, a 21.6 kDa cytosolic EF-hand protein which undergoes a Ca(2+)-induced translocation from cytoplasm to membranes, has been assigned to the newly defined penta EF-hand family. A molecular model of the C-terminal Ca(2+)-binding domain has been generated using as a template the X-ray coordinates of the correspondi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991648v
更新日期:2000-02-01 00:00:00
abstract::To understand the mechanism by which annexin I induces membrane aggregation, a comprehensive mutagenesis of all six Ca2+-binding sites was performed. When the cap residues of type II Ca2+-binding sites were systematically mutated to Ala, a type II site in domain II was shown to be essential for Ca2+-dependent vesicle ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980479w
更新日期:1998-07-14 00:00:00
abstract::A wide variety of biological processes including differentiation, regeneration, and cancer progression are regulated by shedding of membrane-anchored proteins. One of the major sheddases is A Disintegrin And Metalloprotease-17 (ADAM17) whose extracellular region consists of a pro-, a catalytic, a disintegrin-, and a m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00497
更新日期:2015-09-29 00:00:00
abstract::Acarbose is a naturally occurring pseudo-tetrasaccharide. It has been used in conjunction with other drugs in the treatment of diabetes where it acts as an inhibitor of intestinal glucosidases. To probe the interactions of acarbose with other carbohydrate recognition enzymes, the crystal structure of E. coli maltodext...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9828573
更新日期:1999-04-27 00:00:00
abstract::The idea of establishing the amyloid-like fibrillation tendency of pro- and antisurvival proteins of human apoptotic pathways is relevant for delineating the conditions that lead to aberrant differentiation, development, and tissue homeostasis. As the first step in this direction, we report here that the caspase recru...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900626u
更新日期:2009-08-18 00:00:00
abstract::Horse heart cytochrome c has been modified by 8-azido-ATP and the electron-transfer activity of the modified cytochrome c's to bovine heart cytochrome c oxidase (CcO) under physiological ionic strengths has been studied by the laser flash photolysis technique with 5-deazariboflavin and EDTA as the electron donor. The ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00008a035
更新日期:1995-02-28 00:00:00
abstract::UDP-glucose:glycoprotein glucosyltransferase (UGT) is a soluble protein of the endoplasmic reticulum (ER) that operates as a gatekeeper for quality control by preventing transport of improperly folded glycoproteins out of the ER. We report the isolation of two cDNAs encoding human UDP-glucose:glycoprotein glucosyltran...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9916473
更新日期:2000-03-07 00:00:00
abstract::The flavoprotein component (SiR-FP) of the sulfite reductase from Escherichia coli is an octamer containing one FAD and one FMN per polypeptide chain. SiR-FP60, a SiR-FP fragment starting with alanine-52, was overexpressed in E. coli and purified as a monomer. The N-terminal part of the native protein contains thus al...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9728699
更新日期:1998-04-28 00:00:00
abstract::Proton NMR studies were conducted on the complementary 15-mer duplex d(5'-TACTCTTCTTGACCT).(5'-AGGTCAAGAAGAGTA) (designated as unmodified 15-mer duplex) spanning a portion of the mouse c-Ha-ras protooncogene centered around codon 61. Identical studies were carried out on the same sequence, after specific modification ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00155a011
更新日期:1992-10-13 00:00:00