Automation of yeast two-hybrid screening.

We have developed an automated format for screening yeast two-hybrid libraries for protein-protein interactions. The format consists of a liquid array in which pooled library subsets of yeast, expressing up to 1000 different cDNAs, are mated to a yeast strain of the opposite mating type, expressing a protein of interest. Interactors are detected by a liquid assay for beta-galacsidase following prototrophic selection.

Pregnancy and perinatal outcomes in migraineurs using sumatriptan: a prospective study.

Background: Sumatriptan is an acute treatment for migraine which is often used by women in their child-bearing years, and who become unexpectedly pregnant. Within the context of the post-marketing use of sumatriptan injection for the acute treatment of migraine, and in compliance with approved labeling, we wished to compare perinatal pregnancy outcomes in women who did and did not use the drug after conception.

Methods: Open-label, prospective study conducted in 12,339 migraineurs (including 9,861 women) whose demography and consumption pattern of sumatriptan injections were typical, and were predicted to include 150 pregnancies.

Transient and stable gene expression in mammalian cells transduced with a recombinant baculovirus vector.

Recombinant baculoviruses can serve as gene-transfer vehicles for transient expression of recombinant proteins in a wide range of mammalian cell types. Furthermore, by inclusion of a dominant selectable marker in the viral vector, cell lines can be derived that stably express recombinant genes. A virus was constructed containing two expression cassettes controlled by constitutive mammalian promoters: the cytomegalovirus immediate early promoter/enhancer directing expression of green fluorescent protein and the simian virus 40 (SV40) early promoter controlling neomycin phosphotransferase II.

Defective pancreatic beta-cell glycolytic signaling in hepatocyte nuclear factor-1alpha-deficient mice.

Mutations in the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene cause maturity onset diabetes of the young type 3, a form of type 2 diabetes mellitus. In mice lacking the HNF-1alpha gene, insulin secretion and intracellular calcium ([Ca2+]i) responses were impaired following stimulation with nutrient secretagogues such as glucose and glyceraldehyde but normal with non-nutrient stimuli such as potassium chloride. Patch clamp recordings revealed ATP-sensitive K+ currents (KATP) in beta-cells that were insensitive to suppression by glucose but normally sensitive to ATP.

Sulfated cholecystokinin (26-33) induces mild taste aversion conditioning in rats when administered by three different routes.

We investigated the ability of sulfated cholecystokinin (26-33) (CCK-8) and cholecystokinin (30-33) (CCK-4) to induce taste aversion or avoidance conditioning (TAC) in a one-bottle testing paradigm after either intravenous (i.v.), intracerebroventricular (i.

Alpha 1-adrenergic receptor subtype determinants for 4-piperidyl oxazole antagonists.

Mutational studies in conjunction with ligand binding assays were used to examine the basis of alpha1-adrenergic receptor subtype selectivity for a series of 4-piperidyloxazole antagonists. A set of chimeric alpha 1A receptors were created by systematically substituting individual transmembrane domains from alpha 1D adrenergic receptors. The oxazole antagonists exhibited significant reductions in affinity against the receptor construct alpha 1A/D(TM2), and moderate reductions in affinity versus constructs alpha 1A/D(TM5), alpha 1A/B(TM5), and alpha 1A/D(TM6).

Safety review of adult clinical trial experience with lamotrigine.

To date approximately 4000 adults > 12 years of age have been treated with lamotrigine in Glaxo Wellcome sponsored clinical trials. Review of the data from these trials shows lamotrigine to be effective and well tolerated in both add-on and monotherapy treatment. Safety of lamotrigine was comparable to that of other anticonvulsants in add-on controlled clinical trials.

Inhibition of establishment of primary and micrometastatic tumors by a urokinase plasminogen activator receptor antagonist.

Tumor establishment and metastasis are dependent on extracellular matrix proteolysis, tumor cell migration, and angiogenesis. Urokinase plasminogen activator (uPA) and its receptor are essential mediators of these processes. The purpose of this study was to investigate the effect of a recombinant human uPAR antagonist on growth, establishment, and metastasis of tumors derived from human cancer cell lines.

Human recombinant phosphodiesterase 4B2B binds (R)-rolipram at a single site with two affinities.

The interactions between (R)-rolipram and purified human recombinant low-Km, cAMP-specific phosphodiesterase (HSPDE4B2B) constructs were investigated using biochemical, kinetic, and biophysical approaches. The full-length protein (amino acids 1-564) and an N-terminal truncated protein (amino acids 81-564) exhibited high-affinity (R)-rolipram binding, whereas an N-terminal and C-terminal truncated protein (amino acids 152-528) lacked high-affinity (R)-rolipram binding. The 152-528 and 81-564 proteins had similar Km's and kcat/Km's and differed less than 4-fold compared with the 1-564 protein.

Unique preclinical characteristics of GG745, a potent dual inhibitor of 5AR.

Selective inhibition of type 2 5alpha-reductase has been shown to be efficacious in the treatment of benign prostatic hyperplasia. Pharmacokinetic and pharmacodynamic results are reported of treatment with a potent inhibitor of both 5alpha-reductase isozymes, GG745, in rats, dogs and men. In the rat, GG745 has a similar effect on DHT-driven prostatic growth as finasteride, another dual 5alpha-reductase inhibitor in this species.

Production of a urokinase plasminogen activator-IgG fusion protein (uPA-IgG) in the baculovirus expression system.

Numerous studies have demonstrated the importance of urokinase plasminogen activator (uPA) and its receptor, uPAR, in the processes of tumor progression and metastasis. Thus, the uPA/uPAR interaction may represent an important target for inhibiting metastatic disease. The baculovirus expression system was used to produce high levels of a secreted uPA-Immunoglobulin G fusion protein (uPA-IgG) which could then be used for displacing uPA from the surface of tumor cells.

Potent inhibition of human neuronal nitric oxide synthase by N(G)-nitro-L-arginine methyl ester results from contaminating N(G)-nitro-L-arginine.

N(G)-Nitro-L-arginine methyl ester (L-NAME), inhibits the three isozymes of nitric oxide synthase (NOS) in vitro and in vivo. The mechanism of NOS inhibition by L-NAME is uncertain. L-NAME was a time-dependent inhibitor of neuronal NOS (nNOS).

Phenylalanine in the second membrane-spanning domain of alpha 1A-adrenergic receptor determines subtype selectivity of dihydropyridine antagonists.

The alpha 1-adrenergic receptors (alpha 1-AR) belong to the G-protein coupled seven-transmembrane biogenic amine receptor family. Three subtypes have been successfully cloned in the alpha 1-adrenergic receptor family, and they share 50% identical amino acid sequences and 70% similarity. We have constructed seven chimeric receptors of the alpha 1A-AR.

Cloning, expression, and distribution of a Ca(2+)-activated K+ channel beta-subunit from human brain.

We have cloned and expressed a Ca(2+)-activated K+ channel beta-subunit from human brain. The open reading frame encodes a 191-amino acid protein possessing significant homology to a previously described subunit cloned from bovine muscle. The gene for this subunit is located on chromosome 5 at band q34 (hslo-beta).

Vectors encoding alternative antibiotic resistance for use in the yeast two-hybrid system.

We have altered the antibiotic resistance of the reporter plasmids and the pJG4-5 activation-domain and pEG202 DNA binding-domain plasmids used in the Brent interaction trap/two-hybrid system. These plasmids were each previously ampicillin-resistant, resulting in an inefficient purification of any one plasmid from a yeast strain containing all three plasmids that constitute the complete interaction trap. By creating derivatives of each of these plasmids expressing either kanamycin or chloramphenicol resistance, along with the parent plasmids, we now have the option to use the interaction trap in yeast with three E.

K+ channels: generating excitement in pancreatic beta-cells.

K+ channels play a key role in cellular physiology by regulating the efflux of K+ ions. They are the most diverse group of ion channel proteins; more than 30 K+ channel genes have been characterized. Regulated by ATP, voltage, and calcium, multiple K+ channels coexist in the beta-cell to regulate membrane potential, cell excitability, and insulin secretion.

Water soluble inhibitors of topoisomerase I: quaternary salt derivatives of camptothecin.

Eleven water soluble 7-substituted quaternary ammonium salt derivatives of 10,11-(methylenedioxy)- and 10,11-(ethylenedioxy)-(20S)-camptothecin were synthesized via the Friedlander reaction followed by nucleophilic displacement with an aromatic amine. All of these compounds were more potent than camptothecin in the in vitro cleavable complex assay. These inherently charged camptothecin derivatives were cytotoxic against three different human tumor cell lines (SKOV3, an ovarian adenocarcinoma; SKVLB a multidrug resistant ovarian adenocarcinoma; and HT-29, a colon carcinoma).

In vivo time-dependent inhibition of human steroid 5 alpha-reductase by finasteride.

Finasteride (17 beta-(N-t-butylcarbamoyl)-4-aza-5 alpha-androstan-1-en-3- one), a time-dependent, irreversible inhibitor of human steroid 5 alpha-reductase (5AR), may only reduce dihydrotestosterone levels in humans by approximately 60% at the doses used clinically. A theoretical model was developed to aid in understanding the in vivo efficacy data of finasteride. According to the theory, whether an enzyme can be inhibited in vivo by an irreversible inhibitor is dependent on the value of a ratio of the observed rate of enzyme inhibition over the rate constant for inhibitor elimination.

Several roles of CCKA and CCKB receptor subtypes in CCK-8-induced and LiCl-induced taste aversion conditioning.

Administration of a relatively large IP dose of sulfated cholecystokinin (26-33) (CCK-8; 1.0 mumol/kg) consistently induced moderate taste aversion conditioning (TAC) using a 20-min, one-bottle test in Long-Evans rats. Because CCK-8 has affinity for both CCKA and CCKB receptor subtypes, we wanted to determine the subtype involved in CCK-8-induced TAC.

Mechanism of time-dependent inhibition of 5 alpha-reductases by delta 1-4-azasteroids: toward perfection of rates of time-dependent inhibition by using ligand-binding energies.

Finasteride (17 beta-N-tert-butylcarbamoyl-4-aza-5 alpha-androstan-1-en-3- one) is a time-dependent, apparently irreversible inhibitor of 5 alpha-reductases, but does not fully inhibit the activity of 5 alpha-reductase in vivo. This limited efficacy has been attributed to its slow rate of inhibition against the type-1 isozyme [Tian, G. (1995) J.

HIV-1 protease specificity derived from a complex mixture of synthetic substrates.

A rapid and semiquantitative method is described for determining the relative kcat/Km for individual peptides in defined substrate mixtures. The method utilizes electrospray ionization/mass spectrometry alone to semiquantitatively determine relative peptide substrate turnover rates. Unlike previous studies, in which chromatographic separation of individual peptide species was required, this mass spectrometric-based method relies strictly on the ability to ionize and detect simultaneously all peptide species in a defined mixture.