Search results for "binding"

Interaction of Bacillus thuringiensis Toxins with Larval Midgut Binding Sites of Helicoverpa armigera (Lepidoptera: Noctuidae)

2004

ABSTRACT In 1996, Bt-cotton (cotton expressing a Bacillus thuringiensis toxin gene) expressing the Cry1Ac protein was commercially introduced to control cotton pests. A threat to this first generation of transgenic cotton is the evolution of resistance by the insects. Second-generation Bt-cotton has been developed with either new B. thuringiensis genes or with a combination of cry genes. However, one requirement for the “stacked” gene strategy to work is that the stacked toxins bind to different binding sites. In the present study, the binding of 125 I-labeled Cry1Ab protein ( 125 I-Cry1Ab) and 125 I-Cry1Ac to brush border membrane vesicles (BBMV) of Helicoverpa armigera was analyzed in com…

Global variation in the genetic and biochemical basis of diamondback moth resistance to Bacillus thuringiensis

1997

Insecticidal proteins from the soil bacterium Bacillus thuringiensis (Bt) are becoming a cornerstone of ecologically sound pest management. However, if pests quickly adapt, the benefits of environmentally benign Bt toxins in sprays and genetically engineered crops will be short-lived. The diamondback moth ( Plutella xylostella ) is the first insect to evolve resistance to Bt in open-field populations. Here we report that populations from Hawaii and Pennsylvania share a genetic locus at which a recessive mutation associated with reduced toxin binding confers extremely high resistance to four Bt toxins. In contrast, resistance in a population from the Philippines shows multilocus control, a …

Downregulation of a Chitin Deacetylase-Like Protein in Response to Baculovirus Infection and Its Application for Improving Baculovirus Infectivity

2009

ABSTRACT Several expressed sequence tags (ESTs) with homology to chitin deacetylase-like protein (CDA) were selected from a group of Helicoverpa armigera genes whose expression changed after infection with H. armigera single nucleopolyhedrovirus (HearNPV). Some of these ESTs coded for a midgut protein containing a chitin deacetylase domain (CDAD). The expressed protein, HaCDA5a, did not show chitin deacetylase activity, but it showed a strong affinity for binding to chitin. Sequence analysis showed the lack of any chitin binding domain, described for all currently known peritrophic membrane (PM) proteins. HaCDA5a has previously been detected in the H. armigera PM. Such localization, togethe…

Editorial: Timing the Brain: From Basic Sciences to Clinical Implications

2022

Discovery of benzimidazole-based Leishmania mexicana cysteine protease CPB2.8ΔCTE inhibitors as potential therapeutics for leishmaniasis

2018

Abstract: Chemotherapy is currently the only effective approach to treat all forms of leishmaniasis. However, its effectiveness is severely limited due to high toxicity, long treatment length, drug resistance, or inadequate mode of administration. As a consequence, there is a need to identify new molecular scaffolds and targets as potential therapeutics for the treatment of this disease. We report a small series of 1,2‐substituted‐1H‐benzo[d]imidazole derivatives (9ad) showing affinity in the submicromolar range (Ki = 0.150.69 μM) toward Leishmania mexicanaCPB2.8ΔCTE, one of the more promising targets for antileishmanial drug design. The compounds confirmed activity in vitro against intrace…

�ber die Bedeutung der Plasmaproteinbindung f�r Verteilung und Wirkung von Tranquillantien vom Benzodiazepintyp

1977

This paper discusses the problem if the plasma protein binding of benzodiazepine derivatives can influence distribution and pharmacological activity of the drugs. The distribution of the benzodiazepines in the organism is influenced not only by the plasma protein binding of the drugs, but also by several other factors, especially since the drugs are mostly lipophilic. Thus, an effect of the plasma protein binding on the distribution can only be expected if the benzodiazepine derivative is highly bound to the plasma proteins. Thus results have been shown only for diazepam and chlordiazepoxid, which indicate an effect of the plasma protein binding on distribution and pharmacological activity,…

Biphasic Erk1/2 activation sequentially involving Gs and Gi signaling is required in beta3-adrenergic receptor-induced primary smooth muscle cell pro…

2013

Abstract The beta3 adrenergic receptor (B3-AR) reportedly induces cell proliferation, but the signaling pathways that were proposed, involving either Gs or Gi coupling, remain controversial. To further investigate the role of G protein coupling in B3-AR induced proliferation, we stimulated primary human myometrial smooth muscle cells with SAR150640 (B3-AR agonist) in the absence or presence of variable G-protein inhibitors. Specific B3-AR stimulation led to an Erk1/2 induced proliferation. We observed that the proliferative effects of B3-AR require two Erk1/2 activation peaks (the first after 3 min, the second at 8 h). Erk1/2 activation at 3 min was mimicked by forskolin (adenylyl-cyclase a…

Identification of Novel Anthracycline Resistance Genes and Their Inhibitors

2021

Differentially expressed genes have been previously identified by us in multidrug-resistant tumor cells mainly resistant to doxorubicin. In the present study, we exemplarily focused on some of these genes to investigate their causative relationship with drug resistance. HMOX1, NEIL2, and PRKCA were overexpressed by lentiviral-plasmid-based transfection of HEK293 cells. An in silico drug repurposing approach was applied using virtual screening and molecular docking of FDA-approved drugs to identify inhibitors of these new drug-resistant genes. Overexpression of the selected genes conferred resistance to doxorubicin and daunorubicin but not to vincristine, docetaxel, and cisplatin, indicating…

Low temperature optical spectroscopy of low-spin ferric hemeproteins

1996

We report the Soret absorption spectra (500-350 nm) of the cyanomet derivatives of human hemoglobin and horse myoglobin, in the temperature range 300-20 K and in two different solvents (65% v/v glycerol-water or 65% v/v ethylene glycol-water). In order to obtain information on stereodynamic properties of active site of the two hemeproteins, we perform an analysis of the band profiles within the framework of electron-vibrations coupling. This approach enables us to single out the various contributions to the spectral bandwidth, such as those arising from non-radiative decay of the excited electronic state (homogeneous broadening) and from the coupling of the electronic transition i) with hig…

Cu2+and AMP complexation of enlarged tripodal polyamines

2006

The synthesis, characterization, Cu2+ coordination and interaction with AMP of three tripodal polyamines are reported. The polyamines are based on the structure of the tetraamine (tren) which has been enlarged with three propylamino functionalities (TAL), with a further anthrylmethyl fragment at one of its terminal primary nitrogens (ATAL) or with naphthylmethyl fragments at its three ends (N3TAL). The protonation constants of all three polyamines show that at pH 6, all six primary and secondary nitrogen atoms in the arms are protonated. The interaction with Cu2+ and AMP (adenosine-5′-monophosphate) has been studied by potentiometric, UV-Vis, ESI-MS spectroscopy and NMR techniques. pH-Metri…