Search results for "binding site"
showing 10 items of 856 documents
Ein Bindungsstellenmodell für H2-Antagonisten vom 4-Pyrimidinon-Typ
1985
In einer Reihe von 17 Histamin-H2-antagonistisch wirksamen 5-substituierten 4-Pyrimidinonen wird durch Berechnung von Wechselwirkungsenergien ein Modell fur die Rezeptorbindungsstelle des Substituenten am C-5 des Pyrimidinons vorgeschlagen. Als Bindungsstelle fungiert die Aminosaure Arginin. A Binding Site Model for H2-Receptor Antagonists of the 4-Pyrimidone Type Based on calculations of the energies of interaction for a series of seventeen 5-substituted 4-pyrimidones with H2-antagonistic activity, a receptor binding site model for substituents at C-5 of the pyrimidone ring is proposed. The binding site is modeled using the amino acid arginine.
ElaC Encodes a Novel Binuclear Zinc Phosphodiesterase
2002
ElaC is a widespread gene found in eubacteria, archaebacteria, and mammals with a highly conserved sequence. Two human ElaC variants were recently associated with cancer (Tavtigian, S. V., Simard, J., Teng, D. H., Abtin, V., Baumgard, M., Beck, A., Camp, N. J., Carillo, A. R., Chen, Y., Dayananth, P., Desrochers, M., Dumont, M., Farnham, J. M., Frank, D., Frye, C., Ghaffari, S., Gupte, J. S., Hu, R., Iliev, D., Janecki, T., Kort, E. N., Laity, K. E., Leavitt, A., Leblanc, G., McArthur-Morrison, J., Pederson, A., Penn, B., Peterson, K. T., Reid, J. E., Richards, S., Schroeder, M., Smith, R., Snyder, S. C., Swedlund, B., Swensen, J., Thomas, A., Tranchant, M., Woodland, A. M., Labrie, F., Sko…
Binding of Insecticidal Crystal Proteins of Bacillus thuringiensis to the Midgut Brush Border of the Cabbage Looper, Trichoplusia ni (Hübner) (Lepido…
1994
The susceptibility of Trichoplusia ni larvae to several Bacillus thuringiensis insecticidal crystal proteins (ICPs) was tested. Neonatal larvae proved to be susceptible to solubilized trypsin-treated CryIA(a), CryIA(b), and CryIA(c) (50% lethal concentrations [LC 50 s], 570, 480, and 320 ng/cm 2 , respectively) but showed little susceptibility to CryIB and CryID (LC 50 s, 5,640 and 2,530 ng/cm 2 , respectively). The toxicity of ICPs was correlated to binding to the epithelial brush border of the midgut, as revealed by immunocytochemical staining with monoclonal antibodies. In vitro binding experiments with iodinated ICPs and brush border membrane vesicles indicated that CryIA(b) and CryIA(…
THE FINE STRUCTURE OF O2 Hb BINDING IN ANIMALS: SALMO IRIDEUS
1980
Publisher Summary This chapter discusses the experimental results on study of the fine structure of O 2 Hb binding in animals. It is evident that the n ( S ) function represents a new tool to look at homotropic interactions, both qualitatively and quantitatively. At the moment, there are four applications: (1) study of molecular mechanism; (2) study of effectors, also pharmacological; (3) improved characterization of O 2 Hb binding, also in pathological cases; and (4) comparative studies in animals. Whole blood of fish is also investigated because usually there are found several hemoglobins. During registration of the O 2 binding curve, pH is not kept constant. Assuming that the Donnan fact…
Occurrence of three different binding sites forBacillus thuringiensisδ-endotoxins in the midgut brush border membrane of the potato tuber moth,phthor…
1994
The potato tuber moth is susceptible to at least three insecticidal crystal proteins (ICPs) from Bacillus thuringiensis: CrylA(b), CrylB, and CrylC. To design useful combinations of toxin genes either in transgenic plants or in new genetically modified B. thuringiensis strains, it is necessary to determine the binding characteristics of the different ICPs so as not to combine a pair sharing the same binding site. This has been accomplished using two different techniques: 125I-labeling of the ICPs with further measurement of the radioactivity bound to brush border membrane vesicles, and microscopic visualization of the bound ICPs by enzyme-linked reagents such as antibodies or streptavidin u…
Unshared binding sites for Bacillus thuringiensis Cry3Aa and Cry3Ca proteins in the weevil Cylas puncticollis (Brentidae)
2016
Bacillus thuringiensis Cry3Aa and Cry3Ca proteins have been reported to be toxic against the African sweetpotato pest Cylas puncticollis. In the present work, the binding sites of these proteins in C. puncticollis brush border vesicles suggest the occurrence of different binding sites, but only one of them is shared. Our results suggest that pest resistance mediated by alteration of the shared Cry-receptor binding site might not render both Cry proteins ineffective.
Extent of variation of the Bacillus thuringiensis toxin reservoir: the case of the geranium bronze, Cacyreus marshalli butler (Lepidoptera: Lycaenida…
2002
ABSTRACT Despite the fact that around 200 cry genes from Bacillus thuringiensis have already been cloned, only a few Cry proteins are toxic towards a given pest. A crucial step in the mode of action of Cry proteins is binding to specific sites in the midgut of susceptible insects. Binding studies in insects that have developed cross-resistance discourage the combined use of Cry proteins sharing the same binding site. If resistance management strategies are to be implemented, the arsenal of Cry proteins suitable to control a given pest may be not so vast as it might seem at first. The present study evaluates the potential of B. thuringiensis for the control of a new pest, the geranium bronze…
Candida antarctica Lipase A-Based Enantiorecognition of a Highly Strained 4-Dibenzocyclooctynol (DIBO) Used for PET Imaging
2020
The enantiomers of aromatic 4-dibenzocyclooctynol (DIBO), used for radiolabeling and subsequent conjugation of biomolecules to form radioligands for positron emission tomography (PET), were separated by kinetic resolution using lipase A from Candida antarctica (CAL-A). In optimized conditions, (R)-DIBO [(R)-1, ee 95%] and its acetylated (S)-ester [(S)-2, ee 96%] were isolated. In silico docking results explained the ability of CAL-A to differentiate the enantiomers of DIBO and to accommodate various acyl donors. Anhydrous MgCl2 was used for binding water from the reaction medium and, thus, for obtaining higher conversion by preventing hydrolysis of the product (S)-2 into the starting materi…
Conserved histidine and tyrosine determine spectral responses through the water network in Deinococcus radiodurans phytochrome
2022
Funding Information: This work was supported by Academy of Finland grants 285461 (H.T.), 330678 (H.T., J.R.), 277194 (H.L.), and 290677 (S.M.). We acknowledge the European Synchrotron Radiation Facility (ESRF) for providing synchrotron access for crystal data collection. We thank Prof. Janne Ihalainen (University of Jyväskylä) for all the help in all aspects of the paper, Prof. Gerrit Groenhof (University of Jyväskylä) for support, and Prof. Nikolai V. Tkachenko (Tampere University) for help and facilities for time-resolved absorption spectroscopy. We also thank M.Sc. Alli Liukkonen (University of Jyväskylä) and Dr. Heikki Häkkänen (University of Jyväskylä) for the assistance in laboratory …
Uncapping the N-terminus of a ubiquitous His-tag peptide enhances its Cu2+ binding affinity
2019
Metal complexes with an N-terminally free and N-terminally acetylated polyhistidine region of Echis ocellatus venom, with an interesting His-rich motif present in numerous metal binding proteins from all kingdoms of life (DHDHDHHHHHHPGSSV-NH2 and Ac-DHDHDHHHHHHPGSSV-NH2) show the role of the free amino group in the thermodynamic enhancement of Cu2+, Ni2+ and Zn2+ binding. In the studied sequences, Cu2+ can be coordinated by different sets of imidazole rings, and a 3–10 helix is detected in close proximity of Cu2+ binding sites. The complexes are more stable than those with a typical His6-tag, despite a similar copper(II) coordination mode in both cases.