Thousandfold signal increase using field-amplified sample stacking for on-chip electrophoresis.
AuthorsJung B, Bharadwaj R, Santiago JG
JournalElectrophoresis
PubMed ID14595694
'Field-amplified sample stacking (FASS) leverages conductivity gradients between a volume of injected sample and the background buffer to increase sample concentration. A major challenge in applying FASS to on-chip assays is the initial setup of high-conductivity gradient boundaries in the region of the injected sample volume. We have designed, fabricated, ... More
Inter- and intramolecular fluorescence quenching of organic dyes by tryptophan.
AuthorsMarmé N, Knemeyer JP, Sauer M, Wolfrum J
JournalBioconjug Chem
PubMed ID14624626
'Steady-state and time-resolved fluorescence measurements were performed to elucidate the fluorescence quenching of oxazine, rhodamine, carbocyanine, and bora-diaza-indacene dyes by amino acids. Among the natural amino acids, tryptophan exhibits the most pronounced quenching efficiency. Especially, the red-absorbing dyes ATTO 655, ATTO 680, and the oxazine derivative MR 121 are strongly ... More
Toxicity of organic fluorophores used in molecular imaging: literature review.
AuthorsAlford R, Simpson HM, Duberman J, Hill GC, Ogawa M, Regino C, Kobayashi H, Choyke PL,
JournalMol Imaging
PubMed ID20003892
'Fluorophores are potentially useful for in vivo cancer diagnosis. Using relatively inexpensive and portable equipment, optical imaging with fluorophores permits real-time detection of cancer. However, fluorophores can be toxic and must be investigated before they can be administered safely to patients. A review of published literature on the toxicity of ... More
Interaction of fluorescence labeled single-stranded DNA with hexameric DNA-helicase RepA: a photon and fluorescence correlation spectroscopy study.
AuthorsXu H, Frank J, Trier U, Hammer S, Schröder W, Behlke J, Schäfer-Korting M, Holzwarth JF, Saenger W
JournalBiochemistry
PubMed ID11401568
'Fluorescence correlation spectroscopy (FCS) was used to characterize the interaction of fluorescence labeled single-stranded DNA (ssDNA) with hexameric RepA DNA-helicase (hRepA) encoded by plasmid RSF1010. The apparent dissociation constants, Kd(app), for the equilibrium binding of 12mer, 30mer, and 45mer ssDNA 5''-labeled with BFL to hRepA dimer in the presence of ... More
Activation and inhibition of adenylyl cyclase isoforms by forskolin analogs.
AuthorsPinto C, Papa D, Hübner M, Mou TC, Lushington GH, Seifert R,
JournalJ Pharmacol Exp Ther
PubMed ID18184830
'Adenylyl cyclase (AC) isoforms 1 to 9 are differentially expressed in tissues and constitute an interesting drug target. ACs 1 to 8 are activated by the diterpene, forskolin (FS). It is unfortunate that there is a paucity of AC isoform-selective activators. To develop such compounds, an understanding of the structure/activity ... More
Fluorescent Bocillins: synthesis and application in the detection of penicillin-binding proteins.
AuthorsGee KR, Kang HC, Meier TI, Zhao G, Blaszcak LC
JournalElectrophoresis
PubMed ID11332764
Novel fluorescent analogs of penicillin V were synthesized and evaluated for efficacy in the detection of penicillin binding proteins (PBPs). These molecules include the full structure of penicillin V, with the potent Bodipy fluorophore attached to the para-position of the penicillin V phenyl group. The green fluorescent Bocillin FL and ... More
Synthesis, chiroptical properties, and solid-state structure determination of two new chiral dipyrrin difluoroboryl chelates.
AuthorsGossauer A, Nydegger F, Kiss T, Sleziak R, Stoeckli-Evans H
JournalJ Am Chem Soc
PubMed ID14871109
Two new types of optically active BODIPY fluorophores bearing chiral phenyl substituents either at the meso-position or at both external alpha-positions have been synthesized. Their chiroptical properties are strongly dependent both on the position of the chiral group and on the protonation of the chromophore. The solid-state structures of one ... More
A synthesis of 7 alpha-substituted estradiols: synthesis and biological evaluation of a 7 alpha-pentyl-substituted BODIPY fluorescent conjugate and a fluorine-18-labeled 7 alpha-pentylestradiol analog.
AuthorsFrench AN, Wilson SR, Welch MJ, Katzenellenbogen JA
JournalSteroids
PubMed ID8493705
In an effort to assist in the preparation of ligands for the study of the estrogen receptor (ER), we have developed a new synthesis of 7 alpha-substituted estradiols. The key step in the synthesis involves a copper-catalyzed, alpha-selective, 1,6-conjugate addition of 4-pentenyl magnesium bromide to a suitably protected 6-dehydrotestosterone derivative. ... More
Xanthamide fluorescent dyes.
AuthorsGao J, Wang P, Giese RW
JournalAnal Chem
PubMed ID12510765
Two derivatives of fluorescein, termed "xanthamides," were prepared from fluorescein, an inexpensive dye. Relative to fluorescein, which contains a 6-phenolic OH and a 2'-carboxyl, the first derivative (5) contains a carboxymethyl ether at the 6-position and a secondary amide of dimethylamine at the 2'-position. The second derivative (8) contains a ... More
Development of a biologically active fluorescent-labeled calcitriol and its use to study hormone binding to the vitamin D receptor.
AuthorsBarsony J, Renyi I, McKoy W, Kang HC, Haugland RP, Smith CL
JournalAnal Biochem
PubMed ID8533897
To gain better insight into the mechanism of steroid receptor activation and calcitriol action, we have developed the first pharmacologically relevant fluorescent-labeled ligand for the vitamin D receptor (VDR). Purity and structure of three BODIPY-labeled calcitriol derivatives were characterized by TLC, HPLC, and 1H-NMR spectroscopy. 3 beta-BODIPY-calcitriol was the most ... More
Engineering of protease variants exhibiting high catalytic activity and exquisite substrate selectivity.
AuthorsVaradarajan N, Gam J, Olsen MJ, Georgiou G, Iverson BL
JournalProc Natl Acad Sci U S A
PubMed ID15867160
The exquisite selectivity and catalytic activity of enzymes have been shaped by the effects of positive and negative selection pressure during the course of evolution. In contrast, enzyme variants engineered by using in vitro screening techniques to accept novel substrates typically display a higher degree of catalytic promiscuity and lower ... More
Hydroxyl-specific fluorescence labeling of ABP-deoxyguanosine, PhIP-deoxyguanosine, and AFB1-formamidopyrimidine with BODIPY-FL.
AuthorsJang HG, Park M, Wishnok JS, Tannenbaum SR, Wogan GN
JournalAnal Biochem
PubMed ID17081492
Detection and analysis of DNA adducts resulting from endogenous or exogenous exposures to carcinogens are essential not only for quantifying biologically effective doses but also for establishing relationships between exposure and cancer risk. We have developed and validated a procedure of high sensitivity and specificity based on fluorescence labeling of ... More
Direct, ultrasensitive, and selective optical detection of protein toxins using multivalent interactions.
AuthorsSong X, Swanson BI
JournalAnal Chem
PubMed ID10366891
Three highly sensitive, selective, and reagent-free optical signal transduction methods for detection of polyvalent proteins have been developed by directly coupling distance-dependent fluorescence self-quenching and/or resonant-energy transfer to the protein-receptor binding events. The ganglioside GM1, as the recognition unit for cholera toxin (CT), was covalently labeled with fluorophores and then ... More
Convenient and efficient synthesis of functionalized oligopyridine ligands bearing accessory pyrromethene-BF2 fluorophores.
AuthorsUlrich G, Ziessel R
JournalJ Org Chem
PubMed ID15058955
The synthesis of stable and highly luminescent pyridine-, bipyridine-, phenanthroline-, bipyrimidine-, and terpyridine-based ligands bearing one or two 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (bodipy) modules has demonstrated the advantages of three different protocols which have been adapted in light of the chemical stability of the alkyne-grafted starting building blocks and the chemical reactivity of ... More
A unique fluorescent phenylalkylamine probe for L-type Ca2+ channels. Coupling of phenylalkylamine receptors to Ca2+ and dihydropyridine binding sites.
AuthorsKnaus HG, Moshammer T, Kang HC, Haugland RP, Glossmann H
JournalJ Biol Chem
PubMed ID1310311
The first fluorescently labeled phenylalkylamine, DMBODIPY-PAA (5-(3-[3-(4,4-difluoro-5,7-dimethyl-3a, 4a-diaza-4-bora-indacen-3-yl)propionamido] phenethyl-N-methylamino)-2-isopropyl-2-(3,4,5-trimethoxyphenyl)-valer onitrile) has been introduced for L-type Ca2+ channel research. DMBODIPY-PAA binds reversibly to L-type Ca2+ channels purified from rabbit skeletal muscle microsomes by wheat germ agglutinin-Sepharose chromatography. In this preparation DMBODIPY-PAA labels 412 pmol of phenylalkylamine receptors/mg of protein with a ... More
Characterization of cholesterol-sphingomyelin domains and their dynamics in bilayer membranes.
AuthorsSamsonov AV, Mihalyov I, Cohen FS
JournalBiophys J
PubMed ID11509362
Lipids segregate with each other into small domains in biological membranes, which can facilitate the associations of particular proteins. The segregation of cholesterol and sphingomyelin (SPM) into domains known as rafts is thought to be especially important. The formation of rafts was studied by using planar bilayer membranes that contained ... More