Mapping the molecular structure of the voltage-dependent sodium channel. Distances between the tetrodotoxin and Leiurus quinquestriatus quinquestriatus scorpion toxin receptors.
AuthorsAngelides KJ, Nutter TJ
JournalJ Biol Chem
PubMed ID6311831
'The Leiurus quinquestriatus quinquestriatus receptor site of the voltage-dependent sodium channel has been characterized using several fluorescent scorpion toxins. The derivatives show fluorescence enhancements upon binding to the receptor site on the channel together with blue shifts. The fluorescence properties of the bound probes indicate a conformationally flexible, hydrophobic site. ... More
Nonlocal interactions stabilize long range loops in the initial folding intermediates of reduced bovine pancreatic trypsin inhibitor.
AuthorsIttah V, Haas E
JournalBiochemistry
PubMed ID7535565
'A search for the topology of the chain folding of reduced bovine pancreatic trypsin inhibitor (BPTI), in unfolded and partially folded states, was done by means of time resolved dynamic nonradiative excitation energy transfer (ET) measurements. Four double labeled BPTI derivatives were used in which the donor was attached to ... More
Stable association between G alpha(q) and phospholipase C beta 1 in living cells.
AuthorsDowal L, Provitera P, Scarlata S
JournalJ Biol Chem
PubMed ID16754659
'Signal transduction through G alpha(q) involves stimulation of phospholipase C beta (PLC beta) that results in increased intracellular Ca2+ and activation of protein kinase C. We have measured complex formation between G alpha(q) and PLC beta1 in vitro and in living PC12 and HEK293 cells by fluorescence resonance energy transfer. ... More
Two-color labeling of temporally defined protein populations in mammalian cells.
AuthorsBeatty KE, Tirrell DA,
JournalBioorg Med Chem Lett
PubMed ID18774715
'The proteome undergoes complex changes in response to disease, drug treatment, and normal cellular signaling processes. Characterization of such changes requires methods for time-resolved protein identification and imaging. Here, we describe the application of two reactive methionine (Met) analogues, azidohomoalanine (Aha) and homopropargylglycine (Hpg), to label two protein populations in ... More
A dimerization hierarchy in the transmembrane domains of the HER receptor family.
AuthorsDuneau JP, Vegh AP, Sturgis JN
JournalBiochemistry
PubMed ID17253768
'Bitopic membrane proteins offer an opportunity for studying transmembrane domain interactions without the structural complexity inherent to multitopic integral membrane proteins. To date, only homomeric associations have been extensively studied quantitatively. Here we propose to assess the thermodynamics of heteromeric associations, which opens the way to investigating specificity and selectivity. ... More
Coumarin-Ser-Asp-Lys-Pro-OH, a fluorescent substrate for determination of angiotensin-converting enzyme activity via high-performance liquid chromatography.
AuthorsCheviron N, Rousseau-Plasse A, Lenfant M, Adeline MT, Potier P, Thierry J
JournalAnal Biochem
PubMed ID10805521
'N-Acetyl-Ser-Asp-Lys-Pro-OH (AcSDKP-OH), a negative regulator of hematopoietic stem cell proliferation, is shown to be a physiological substrate of angiotensin I-converting enzyme (ACE), a zinc-dipeptidyl carboxypeptidase, involved in cardiovascular homeostasis. Recently, a study carried out on captopril-treated volunteers revealed that the kinetics of [3H]AcSDKP-OH hydrolysis in vitro in the plasma of ... More
Fluorescence resonance energy transfer on the voltage-dependent sodium channel. Spatial relationship and site coupling between the batrachotoxin and Leiurus quinquestriatus quinquestriatus alpha-scorpion toxin receptors.
AuthorsAngelides KJ, Brown GB
JournalJ Biol Chem
PubMed ID6327667
'A fluorescent N- methylanthraniloyl derivative of the potent depolarizing agent batrachotoxin has been used to probe the structural and conformational properties of the neurotoxin receptor site on the voltage-dependent sodium channel. Batrachotoxin A 20-alpha-N- methylanthranilate (BTX-NMA) retains high affinity for its receptor site on the synaptosomal sodium channel with a ... More
Three-color immunofluorescence histochemistry allowing triple labeling within a single section.
AuthorsStaines WA, Meister B, Melander T, Nagy JI, Hökfelt T
JournalJ Histochem Cytochem
PubMed ID2891745
'We describe a procedure for simultaneous immunohistochemical localization of three different neuropeptides, neurotransmitters, or neurotransmitter enzymes within one and the same tissue section and present a number of examples of its application within the brain and periphery. Primary antibodies from three different species were bound to three different neurochemical substances ... More
Estimation of intramolecular distance distributions in bovine pancreatic trypsin inhibitor by site-specific labeling and nonradiative excitation energy-transfer measurements.
AuthorsAmir D, Haas E
JournalBiochemistry
PubMed ID2441742
'A series of four bovine pancreatic trypsin inhibitor (BPTI) derivatives, site specifically labeled by (2-methoxy-1-naphthyl)methyl (MNA) at the N-terminal amino group and by [7-(dimethylamino)-coumarin-4-yl]acetyl (DA-coum) at one of the four epsilon-amino groups, was prepared. The four derivatives, N alpha-MNA-Arg1-N epsilon-DA-coum-Lysn-BPTI [(1-n)BPTI] (n = 15, 26, 41, and 46), were purified ... More
Characterization of protein-hapten conjugates. 2. Electrospray mass spectrometry of bovine serum albumin-hapten conjugates.
AuthorsAdamczyk M, Gebler JC, Mattingly PG
JournalBioconjug Chem
PubMed ID8853461
Fifteen hapten-bovine serum albumin (BSA) conjugates were prepared from five commercially available activated haptens. Each hapten was coupled to BSA at three different ratios. The conjugates were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and two mass spectrometry (MS) methods: matrix-assisted laser desorption ionization (MALDI) and liquid chromatography-electrospray ... More
Galphaq binds to p110alpha/p85alpha phosphoinositide 3-kinase and displaces Ras.
AuthorsBallou LM, Chattopadhyay M, Li Y, Scarlata S, Lin RZ
JournalBiochem J
PubMed ID16268778
Several studies have reported that activation of G(q)-coupled receptors inhibits PI3K (phosphoinositide 3-kinase) signalling. In the present study, we used purified proteins to demonstrate that Galpha(q) directly inhibits p110alpha/p85alpha PI3K in a GTP-dependent manner. Activated Galpha(q) binds to the p110alpha/p85alpha PI3K with an apparent affinity that is seven times stronger ... More
Nonlocal interactions stabilize compact folding intermediates in reduced unfolded bovine pancreatic trypsin inhibitor.
AuthorsGottfried DS, Haas E
JournalBiochemistry
PubMed ID1281424
To further our understanding of the protein folding process, it is desirable to examine the structural intermediates (equilibrium and kinetic) that are populated between the statistical coil state and the folded molecule. X-ray crystallography and NMR structural studies are unable to determine long-range distances in proteins under denaturing solution conditions. ... More
Reduced bovine pancreatic trypsin inhibitor has a compact structure.
AuthorsAmir D, Haas E
JournalBiochemistry
PubMed ID2466482
The conformation of reduced bovine pancreatic trypsin inhibitor (R-BPTI) under reducing conditions was monitored by measurements of nonradiative excitation energy-transfer efficiencies (E) between a donor probe attached to the N-terminal Arg1 residue and an acceptor attached to one of the lysine residues (15, 26, 41, or 46) [Amir, D., & ... More
Structural mapping of the voltage-dependent sodium channel. Distance between the tetrodotoxin and Centruroides suffusus suffusus II beta-scorpion toxin receptors.
AuthorsDarbon H, Angelides KJ
JournalJ Biol Chem
PubMed ID6327664
A 7- dimethylaminocoumarin -4-acetate fluorescent derivative of toxin II from the venom of the scorpion Centruroides suffusus suffusus (Css II) has been prepared to study the structural, conformational, and cellular properties of the beta-neurotoxin receptor site on the voltage-dependent sodium channel. The derivative retains high affinity for its receptor site ... More
Novel fluorescent phospholipids for assays of lipid mixing between membranes.
AuthorsSilvius JR, Leventis R, Brown PM, Zuckermann M
JournalBiochemistry
PubMed ID3663589
A series of fluorescent phospholipids has been synthesized, by a general and versatile procedure, with various fluorescent groups attached to the methyl-terminal half of one acyl chain in an otherwise normal phospholipid structure. Phospholipids labeled with (dialkylamino)coumarin moieties, and to a slightly lesser extent those labeled with a bimane group, ... More
In vitro efficacy of morpholino-modified antisense oligomers directed against tumor necrosis factor-alpha mRNA.
Authors Taylor M F; Paulauskis J D; Weller D D; Kobzik L;
JournalJ Biol Chem
PubMed ID8663413
Chemical modification of antisense oligonucleotides to increase nuclease resistance may improve their efficacy within enzyme-rich cellular targets (e.g. macrophages). We evaluated a panel of morpholino antisense oligomers (M-AS) for their ability to inhibit macrophage tumor necrosis factor-alpha (TNF-alpha) release and compared them to phosphodiester (O-AS) and phosphorothioate (S-AS) types of ... More
A series of site-specific fluorescently labeled BPTI derivatives prepared by nonselective acylation and chromatographic separations.
AuthorsAmir D, Haas E
JournalInt J Pept Protein Res
PubMed ID2419267
Investigation of conformational transitions and, in particular, the folding/unfolding transitions of globular proteins by means of excitation energy transfer measurements depends on the availability of protein derivatives carrying donor and acceptor probes at well-defined pairs of sites. A series of bovine pancreatic trypsin inhibitor (BPTI) derivatives, each labeled at one ... More
Preparation and characterization of fluorescent scorpion toxins from Leiurus quinquestriatus quinquestriatus as probes of the sodium channel of excitable cells.
AuthorsAngelides KJ, Nutter TJ
JournalJ Biol Chem
PubMed ID6311830
Fluorescent derivatives of scorpion toxin V from Leiurus quinquestriatus quinquestriatus have been prepared so that the topographical, dynamic, and cellular properties of the neurotoxin receptor site on the voltage-dependent sodium channel could be studied. Four different modification strategies have been pursued in which acylated, amidinylated, thio-amidinylated, and reductively alkylated scorpion ... More