Abstract:
:Ion channel peptides have been prepared by solid-phase peptide synthesis, labeled with 15N at selected sites, and reconstituted into oriented lipid bilayers. The (Leu-Ser-Ser-Leu-Leu-Ser-Leu)3-CONH2 peptide has previously been shown to exhibit well-defined and discrete ionic conductances when investigated by single-channel measurements [Lear, J. D., et al. (1988) Science 240, 1177]. Proton-decoupled 15N solid-state NMR spectroscopy indicates that (Leu-Ser-Ser-Leu-Leu-Ser-Leu)3-CONH2 preferentially aligns parallel to the membrane surface in excellent agreement with its amphipathic helical structure. However, by carefully choosing the conditions of the membrane environment, significant contributions that are indicative of transmembrane alignments become obvious in the 15N chemical shift solid-state NMR spectra. The data thereby provide experimental evidence for an equilibrium between in-plane and transmembrane-oriented helix configurations where the transmembrane and surface-oriented peptide fractions are in slow exchange. Similar topological equilibria are observed when the N-terminus of the LS21 peptide is acetylated. These observations provide experimental support for previous models, suggesting that the channels observed in single-channel conductance measurements are indeed formed by hexameric transmembrane helical bundles. In contrast, the shorter peptide (Leu-Ser-Ser-Leu-Leu-Ser-Leu)2-CONH2 is oriented parallel to the membrane surface under all conditions tested. This peptide exhibits erratic conductance changes when investigated by electrophysiological methods, probably because it is too short to span the lipid bilayer.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Sudheendra US,Bechinger Bdoi
10.1021/bi050866nsubject
Has Abstractpub_date
2005-09-13 00:00:00pages
12120-7issue
36eissn
0006-2960issn
1520-4995journal_volume
44pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Herpesvirus saimiri encodes a tyrosine kinase interacting protein (Tip) that binds to T-cell-specific tyrosine kinase Lck via multiple sequence motifs and controls its activity. The regulation of Lck by Tip represents a key mechanism in the transformation of human T-lymphocytes during herpesviral infection. In this st...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0485068
更新日期:2004-11-30 00:00:00
abstract::Interaction between aggregates of amyloid beta protein (Abeta) and membranes has been hypothesized by many to be a key event in the mechanism of neurotoxicity associated with Alzheimer's disease (AD). Proposed membrane-related mechanisms of neurotoxicity include ion channel formation, membrane disruption, changes in m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9006397
更新日期:2009-09-22 00:00:00
abstract::The thermodynamics and kinetics of magnesium binding to tRNA(Phe)(yeast) have been studied directly by 25Mg NMR. In 0.17 M Na+(aq), tRNA(Phe) exists in its native conformation and the number of strong binding sites (Ka greater than or equal to 10(4)) was estimated to be 3-4 by titration experiments, in agreement with ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00477a021
更新日期:1990-06-26 00:00:00
abstract::A single amino acid substitution from methionine-184 to valine (M184V) of HIV-1 reverse transcriptase (RT) evokes the 1000-fold 3TC (Lamivudine) resistance by the HIV-1 virus observed in the clinic. The M184V mutant HIV-1 RT was studied to assess its catalytic efficiency during single nucleotide incorporation using a ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990709m
更新日期:1999-07-20 00:00:00
abstract::Geobacillus stearothermophilus T-6 encodes for a beta-xylosidase (XynB2) from family 52 of glycoside hydrolases that was previously shown to hydrolyze its substrate with net retention of the anomeric configuration. XynB2 significantly prefers substrates with xylose as the glycone moiety and exhibits a typical bell-sha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034505o
更新日期:2003-09-09 00:00:00
abstract::The folding kinetics of a 16-residue beta-hairpin (trpzip4) and five mutants were studied by a laser-induced temperature-jump infrared method. Our results indicate that mutations which affect the strength of the hydrophobic cluster lead to a decrease in the thermal stability of the beta-hairpin, as a result of increas...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi052039s
更新日期:2006-02-28 00:00:00
abstract::The effects of pressure, up to 5 kbar, on multilamellar vesicles of 1,2-dipalmitoyl-sn-phosphatidylcholine perdeuterated in the acyl chains (DPPC-d62) were examined by using high-pressure NMR techniques. A deuterium probe was built, and the quadrupole splitting was measured against pressure at various temperatures. Th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00227a022
更新日期:1991-04-02 00:00:00
abstract::Ultraviolet absorption (UV) and circular dichroism (CD) spectra of wheat germ 5S RNA, when compared to tRNAPhe, indicate a largely base-paired and base-stacked helical structure, containing up to 36 base pairs. Fourier-transform infrared (FT-IR) spectra of tRNAPhe and wheat germ ribosomal 5S RNA have been acquired at ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00311a012
更新日期:1984-07-31 00:00:00
abstract::In prokaryotes, the first three enzymes in pyrimidine biosynthesis, carbamoyl phosphate synthetase (CPS), aspartate transcarbamoylase (ATC), and dihydroorotase (DHO), are commonly expressed separately and either function independently (Escherichia coli) or associate into multifunctional complexes (Aquifex aeolicus). I...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801831r
更新日期:2009-02-03 00:00:00
abstract::At pH 5.5, binding of bleomycin relaxed supercoiled ColE1 DNA without breaking it. Binding of tripeptide S, a fragment of the drug containing the bithiazole rings, also relaxed and then recoiled supercoiled DNA, at pH 5.5 and at pH 8.0, where bleomycin is normally active. The unwinding angle was 12 degrees. Both compo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00568a015
更新日期:1979-01-09 00:00:00
abstract::We studied the basic steps of proton transfer through ATP synthase of chloroplasts, CF0CF1, under conditions of proton slip, a conducting stage in the absence of added nucleotides. On the background of a steady transmembrane pH difference, voltage steps were induced by flashing light. Proton intake, transfer, and rele...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00027a008
更新日期:1995-07-11 00:00:00
abstract::Human type beta 2 transforming growth factor (hTGF-beta 2) was purified from tamoxifen-supplemented, serum-free medium conditioned by the human prostatic adenocarcinoma cell line PC-3. The purification of hTGF-beta 2 was monitored in a growth inhibition assay and was achieved by batch purification on methylsilyl-contr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00383a002
更新日期:1987-05-05 00:00:00
abstract::The sliding clamp of the Escherichia coli replisome is now understood to interact with many proteins involved in DNA synthesis and repair. A universal interaction motif is proposed to be one mechanism by which those proteins bind the E. coli sliding clamp, a homodimer of the beta subunit, at a single site on the dimer...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi036229j
更新日期:2004-05-18 00:00:00
abstract::The purified ATP-synthesizing complex from chloroplasts has been reconstituted into phospholipid vesicles with bacteriorhodopsin by use of octyl glucoside. Phosphorylation rates up to 90 mmol of ATP (mg of protein)-1 min-1 have been achieved. The dependence of the steady-state kinetic parameters on external and intern...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00527a018
更新日期:1981-11-24 00:00:00
abstract::The two disparate functions of DCoH1 (dimerization cofactor of HNF-1)/PCD (pterin-4a-carbinolamine dehydratase) are associated with a change in oligomeric state. DCoH dimers enhance the activity of the diabetes-associated transcription factor HNF-1α (hepatocyte nuclear factor-1α), while the PCD activity of DCoH1 homot...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1015056
更新日期:2010-11-30 00:00:00
abstract::Rhodopsin is the photoreceptor in vertebrate rod cells responsible for vision at low light intensities. The photoreactive chromophore in rhodopsin is 11-cis-retinal bound to the protein via a protonated Schiff base with Glu113 as the counterion. We have used the observed 13C NMR chemical shifts of the conjugated retin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00004a037
更新日期:1995-01-31 00:00:00
abstract::Pectate lyase C (pelC) was the first protein in which the parallel beta-helix structure was recognized. The unique features of parallel beta-helix-containing proteins-a relatively simple topology and unusual interactions among side chains-make pelC an interesting protein to study with respect to protein folding. In th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001900v
更新日期:2000-12-26 00:00:00
abstract::The binding of Sp1 transcription factor to DNA is considered a potential target for small ligands designed to interfere with gene transcription. We attempted to distinguish the direct inhibition of the Sp1-binding to DNA in vivo (cell culture) from more indirect effects due to the network of pathways that modulate cel...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi036185e
更新日期:2004-06-15 00:00:00
abstract::The hydrogen exchange behavior of a four-helix bundle protein in low concentrations of denaturant reveals some partially unfolded forms that are significantly more stable than the fully unfolded state. Kinetic folding of the protein, however, is apparently two-state in the absence of the accumulation of early folding ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025872n
更新日期:2002-06-25 00:00:00
abstract::Human Monocyte Chemotactic Protein (MCP)-2 has originally been isolated from stimulated osteosarcoma cells as a chemokine coproduced with MCP-1 and MCP-3. Here, a 5'-end extended MCP-2 cDNA was cloned from a human testis cDNA library. It encoded a 76 residue MCP-2 protein, but differed from the reported bone marrow-de...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980497d
更新日期:1998-09-08 00:00:00
abstract::Doublet signal and singlet-like signal induced in Ca(2+)-depleted PS II were investigated by pulsed EPR in one-dimensionally oriented photosystem (PS) II membranes. The doublet signal showed marked angular dependent change in its spectrum in term of the applied magnetic field, indicating that the magnetic dipole-dipol...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9929406
更新日期:2000-09-12 00:00:00
abstract::The deposition of amyloid-β (Aβ) plaques and tau-based neurofibrillary tangles is a neuropathological feature of Alzheimer's disease (AD). While studies have shown that the Aβ and tau interaction results in elevated AD pathology, the molecular linkage and mechanism of interaction of Aβ and tau are unclear. A recent st...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b01087
更新日期:2020-02-04 00:00:00
abstract::The recruitment and organization of clathrin at endocytic sites first to form coated pits and then clathrin-coated vesicles depend on interactions between the clathrin N-terminal domain (TD) and multiple clathrin binding sequences on the cargo adaptor and accessory proteins that are concentrated at such sites. Up to f...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00065
更新日期:2015-04-28 00:00:00
abstract::Soluble guanylate cyclase (sGC) is a heterodimeric hemoprotein composed of alpha1 and beta1 subunits. sGC is activated by nitric oxide (NO) and therefore plays a central role in NO signal transduction. Activation of sGC by NO is believed to be mediated by the interaction between NO and the heme of sGC. Spectroscopic a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971825x
更新日期:1997-12-16 00:00:00
abstract::The five-membered nitrogen plus heteroatom rings known as azolines or in their oxidized form as azoles are very common in natural products and drugs. The oxidation of thiazoline to thiazole in the cyanobactin class of natural products is one of the several important transformations that are known to alter the biologic...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00835
更新日期:2018-10-16 00:00:00
abstract::The carboxypeptidase inhibitor from Russet Burbank potatoes (C. A. Ryan et al. (1974b), J. Biol. Chem 249, 5495) is a mixture of approximately equal amounts of two polypeptide chains containing 38 and 39 amino acid residues, respectively. The chains differ in their amino terminal sequence only, one beginning with smal...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00677a036
更新日期:1975-03-25 00:00:00
abstract::Cytochromes c require covalent attachment of heme via two thioether bonds at conserved CXXCH motifs, a process accomplished in prokaryotes by eight integral membrane proteins (CcmABCDEFGH), termed System I. Heme is trafficked from inside the cell to outside (via CcmABCD) and chaperoned (holoCcmE) to the cytochrome c s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00427
更新日期:2016-06-07 00:00:00
abstract::The RING or Really Interesting New Gene represents a family of eukaryotic sequences that bind Zn (II) ions and participate in intracellular processes involving protein-protein interaction. Although found in over 400 different proteins, very little is known regarding the structure-function properties of these domains b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701949p
更新日期:2008-03-25 00:00:00
abstract::The fibronectin receptor (FnR), the vitronectin receptor (VnR), and the platelet membrane glycoprotein (GP) IIb-IIIa complex are members of a family of cell adhesion receptors, which consist of noncovalently associated alpha- and beta-subunits. The present study was designed to compare the cDNA-derived protein sequenc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00399a021
更新日期:1987-12-15 00:00:00
abstract::The complete sequence of histone 2B of Drosophila has been determined by using an improved Beckman sequenator. Comparing these data with those previously published by other investigators on the histone 2B of calf [Iwai, K., Hayashi, H., & Ishikawa, K. (1972) J. Biochem. (Tokyo) 72, 357--367], trout [Koostra, A., & Bai...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00592a025
更新日期:1979-12-11 00:00:00