Abstract:
:The membrane stabilization effect of cholesteryl hemisuccinate (CHEMS) and the sensitivity of the CHEMS-phosphatidylethanolamine membranes to protons and calcium ions were studied by differential scanning calorimetry, freeze-fracture electron microscopy, and 31P NMR. (1) At neutral pH, the addition of 8 mol % CHEMS to transesterified egg phosphatidylethanolamine (TPE) raised the lamellar-hexagonal transition temperature of TPE by 11 degrees C. Stable bilayer vesicles were formed when the incorporated CHEMS exceeded 20 mol %. (2) At a pH below 5.5, the protonation of CHEMS enhanced the formation of the hexagonal phase (HII) of TPE. At 25 mol % CHEMS the bilayer-hexagonal transition temperature was lowered by 30 degrees C at pH 4.5. (3) The endothermic acid-induced hexagonal hexagonal transition of TPE-CHEMS was suppressed at 35 mol % CHEMS. However, 31P NMR and electron microscopy indicated that a lamellar-hexagonal transition still occurred at this composition. (4) The main transition of TPE was not affected by the protonation of the incorporated CHEMS, indicating that no macroscopic phase separation occurred in TPE-CHEMS mixtures at low pH. (5) In contrast to the HII-promoting effect of H+, the neutralization of the negative charge on TPE-CHEMS by Ca2+ resulted in aggregates that remained in the lamellar structure even at the hexagonal transition temperature of TPE. It is suggested that calcium might form a complex between CHEMS in apposed bilayers. These results are related to the possible biological function of acidic cholesterol esters in biomembranes.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Lai MZ,Vail WJ,Szoka FCdoi
10.1021/bi00328a013subject
Has Abstractpub_date
1985-03-26 00:00:00pages
1654-61issue
7eissn
0006-2960issn
1520-4995journal_volume
24pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Glycosylation is a common modification that can endow proteins with altered physical and biological properties. Ribonuclease 1 (RNase 1), which is the human homologue of the archetypal enzyme RNase A, undergoes N-linked glycosylation at asparagine residues 34, 76, and 88. We have produced the three individual glycofor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00191
更新日期:2020-09-01 00:00:00
abstract::Barnase, the ribonuclease from Bacillus amyloliquefaciens, has been cloned and expressed in Escherichia coli [Hartley, R. W. (1988) J. Mol. Biol. 202, 913-915], thus enabling the overproduction and site-directed mutagenesis of one of the smallest enzymes (Mr equals 12,382). As barnase is also composed of just a single...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00435a033
更新日期:1989-05-02 00:00:00
abstract::Fluorescence studies of the binding of IKe gene 5 protein to various polynucleotides were performed to obtain insight into the question as to what extent the binding characteristics of the gene 5 proteins of the IKe and M13 phages resemble and/or differ from each other. The fluorescence of IKe gene 5 protein is quench...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00381a037
更新日期:1987-04-07 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::Ferredoxin I from Desulfovibrio africanus (Da FdI) is a small acidic [4Fe-4S] cluster protein that exchanges electrons with pyruvate-ferredoxin oxidoreductase (PFOR), a key enzyme in the energy metabolism of anaerobes. The thermodynamic properties and the electron transfer between PFOR and either native or mutated FdI...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0485878
更新日期:2004-12-14 00:00:00
abstract::Extensive molecular modeling with molecular dynamics simulations and van der Waals energy analyses were used to elucidate the striking finding that a mutagenic benzo[a]pyrene-derived DNA lesion, the base-displaced intercalated 10R-(+)-cis-anti-B[a]P-N(2)-dG (G*), manifests large differences in nucleotide excision repa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi4009177
更新日期:2013-08-20 00:00:00
abstract::Histidinol-phosphate aminotransferase (HspAT) is a key enzyme on the histidine biosynthetic pathway. HspAT catalyzes the transfer of the amino group of L-histidinol phosphate (Hsp) to 2-oxoglutarate to form imidazole acetol phosphate (IAP) and glutamate. Thus, HspAT recognizes two kinds of substrates, Hsp and glutamat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi002769u
更新日期:2001-04-17 00:00:00
abstract::Stopped-flow measurements of protein fluorescence quenching when methotrexate (MTX) binds to dihydrofolate reductase (isoenzyme II) of Streptococcus faecium (SFDHFR II) analyze as the sum of two differentials: a rapid binding phase and a second phase for which the observed rate constant is independent of methotrexate ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00339a010
更新日期:1985-08-27 00:00:00
abstract::Three different cleavable photoactivable heterobifunctional reagents have been synthesized and characterized by proton NMR, 13C NMR, mass spectroscopy, infrared spectroscopy, and thin-layer chromatography. They are the N-hydroxysuccinimide ester of 3-[(4-azidophenyl)dithio]-propionic acid, methyl 3-[(4-azidophenyl)dit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00527a003
更新日期:1981-11-24 00:00:00
abstract::The potassium form of d(CGCGAATTCGCG) solved by X-ray diffraction to 1.75 A resolution indicates that monovalent cations penetrate the primary and secondary layers of the "spine of hydration". Both the sodium [Shui, X., McFail-Isom, L., Hu, G. G., and Williams, L. D. (1998) Biochemistry 37, 8341-8355] and the potassiu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982063o
更新日期:1998-12-01 00:00:00
abstract::Heme-derived linear tetrapyrroles (phytobilins) in phycobiliproteins and phytochromes perform critical light-harvesting and light-sensing roles in oxygenic photosynthetic organisms. A key enzyme in their biogenesis, phycocyanobilin:ferredoxin oxidoreductase (PcyA), catalyzes the overall four-electron reduction of bili...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100728q
更新日期:2010-07-27 00:00:00
abstract::Remodeling of photosynthetic machinery induced by growing spinach plants under low light intensities reveals an up-regulation of light-harvesting complexes and down-regulation of photosystem II and cytochrome b6f complexes in intact thylakoids and isolated grana membranes. The antenna size of PSII increased by 40-60% ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700748y
更新日期:2007-10-02 00:00:00
abstract::The removal of cylclobutane pyrimidine dimers from cellular DNA occurs preferentially in actively transcribed genes of cells subjected to ultraviolet radiation. In contrast, reports concerning the transcription-dependent repair of N-methylpurines formed in cellular DNA following exposure to methylating agents are quit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00005a037
更新日期:1995-02-07 00:00:00
abstract::Sonication of lysophosphatidylcholine (lysoPC; 20 mumol/mL) and cholesterol (chol) in aqueous medium produces lamellar structures over a wide range of concentrations. From 25 to 47 mol % cholesterol, electron microscopy (EM) after negative staining showed extended stacklike lamellae about 40 A thick. From 50 to 60 mol...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00401a059
更新日期:1988-01-12 00:00:00
abstract::Pantothenate synthetase (PS, EC 6.3.2.1) is the last enzyme in the pantothenate biosynthesis pathway, a metabolic pathway identified as a potential target for new antimicrobials. PS catalyzes the ATP-dependent condensation of pantoate and beta-alanine to form pantothenate. Here we report the overexpression, purificati...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1004206
更新日期:2010-08-03 00:00:00
abstract::A likely entry/exit path for nitrogenase substrates, products, and/or protons involves residues α277(Arg), α192(Ser), and α356(Gly), all of which are highly conserved among MoFe proteins from different organisms. The α192(Ser) and α277(Arg) residues form part of a hydrogen-bonded network that also involves α195(His), ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500546k
更新日期:2014-10-07 00:00:00
abstract::Campylobacter jejuni contains a general N-linked glycosylation pathway in which a heptasaccharide is sequentially assembled onto a polyisoprenyl diphosphate carrier and subsequently transferred to the asparagine side chain of an acceptor protein. The enzymes in the pathway function at a membrane interface and have in ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701956x
更新日期:2007-12-18 00:00:00
abstract::The human, cytosolic enzyme isocitrate dehydrogenase 1 (IDH1) reversibly converts isocitrate to α-ketoglutarate (αKG). Cancer-associated somatic mutations in IDH1 result in a loss of this normal function but a gain in a new or neomorphic ability to convert αKG to the oncometabolite 2-hydroxyglutarate (2HG). To improve...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400514k
更新日期:2013-07-02 00:00:00
abstract::A covalently linked actin dimer is identified in solutions of actin prepared from an acetone powder from skeletal muscle. This actin dimer acts as an actin nucleating factor (ANF), decreasing the half-time for spontaneous actin polymerization. ANF reacts with antibodies to both the N- and C-terminal portions of actin ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9914964
更新日期:2000-01-11 00:00:00
abstract::NAD(P)H:quinone oxidoreductase 1 (NQO1) is currently an emerging target in pancreatic cancer. In this report, we describe a series of indolequinones, based on 5-methoxy-1,2-dimethyl-3-[(4-nitrophenoxy)methyl]indole-4,7-dione (ES936), and evaluate NQO1 inhibition and growth inhibitory activity in the human pancreatic M...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700008y
更新日期:2007-05-22 00:00:00
abstract::The interactions between rhodopsin molecules in a micellar detergent solution (octyl glucoside) and in reconstituted phospholipid vesicles were studied in the dark and after bleaching. Resonance energy transfer measurements were used to monitor the proximity between rhodopsin monomers conjugated with a fluorescent don...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00270a030
更新日期:1983-01-04 00:00:00
abstract::DB2277, a heterocyclic diamidine, is a successful design for mixed base pair (bp) DNA sequence recognition. The compound has a central aza-benzimidazole group that forms two H-bonds with a GC bp that has flanking AT bps. The nuclear magnetic resonance structure of the DB2277-DNA complex with an AAGATA recognition site...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00647
更新日期:2018-08-21 00:00:00
abstract::The regulatory (R) subunit of cAMP-dependent protein kinase (cAPK) is a multidomain protein with two tandem cAMP-binding domains, A and B. The importance of cAMP binding on the stability of the R subunit was probed by intrinsic fluorescence and circular dichroism (CD) in the presence and absence of urea. Several mutan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001563q
更新日期:2000-12-12 00:00:00
abstract::Recent studies of DNA hairpin loops have shown considerable dependence of the stability on the sequence of the loop [Senior, M., Jones, R. A., & Breslauer, K. J. (1988a) Proc. Natl. Acad. Sci. U.S.A. 85, 6242-6246; Xodo, L. E., Manzini, G., Quadrifoglio, F., van der Marel, G., & van Boom, J. H. (1989) Biochimie 71, 79...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00181a026
更新日期:1994-04-19 00:00:00
abstract::The interaction between the apoprotein of 6-hydroxy-L-nicotine oxidase from Arthrobacter oxidans and the prosthetic group FAD has been investigated by 13C, 15N, and 31P NMR techniques. The FAD prosthetic group was selectively enriched in 13C and 15N isotopes by adding isotopically labeled riboflavin derivatives to the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00428a016
更新日期:1989-01-24 00:00:00
abstract::Site-directed mutagenesis and high-resolution two-dimensional (2D) proton nuclear magnetic resonance (NMR) were used to probe the structural and functional roles of a highly conserved residue, Asp-49, in the interfacial catalysis by bovine pancreatic phospholipase A2 (PLA2, overexpressed in Escherichia coli). Accordin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00253a009
更新日期:1994-12-13 00:00:00
abstract::The reaction of cytochrome c oxidase (COX) from Rhodobacter sphaeroides with hydrogen peroxide has been studied at alkaline (pH 8.5) and acidic (pH 6.5) conditions with the aid of a stopped-flow apparatus. Absorption changes in the entire 350-800 nm spectral range were monitored and analyzed by a global fitting proced...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi010115v
更新日期:2001-08-14 00:00:00
abstract::The role of the Na,K-ATPase beta-subunit in stabilization of ion-binding sites has been investigated. Treatment of the purified renal Na,K-ATPase with 0.25 M DTT at 40 degrees C for 1 h resulted in 50% loss of Rb occlusion, which correlates with partial reduction of S-S bridges in the extracellular portion of the beta...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00077a029
更新日期:1993-07-06 00:00:00
abstract::GTPases are key players during cellular signaling. Phosphorylation of Rab proteins, which belong to the Ras superfamily of small GTPases regulating intracellular transport, has been implicated in the pathogenesis of Parkinson's disease. For Rab8a, it was shown that serine 111 phosphorylation (pS111) is dependent on th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b00516
更新日期:2019-08-20 00:00:00
abstract::Bicyclomycin is a novel, commercially important antibiotic. Information concerning the site of bicyclomycin inhibition in Escherichia coli has been obtained by the production of bicyclomycin resistant mutants by UV irradiation. Selection by growth in the presence of bicyclomycin of a plasmid clone library generated fr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00065a007
更新日期:1993-04-13 00:00:00