73630-07-6Relevant articles and documents
Long-Term Tracking and Dynamically Quantifying of Reversible Changes of Extracellular Ca2+ in Multiple Brain Regions of Freely Moving Animals
Liu, Yuandong,Liu, Zhichao,Zhao, Fan,Tian, Yang
, p. 14429 - 14437 (2021/05/03)
Understanding physiological and pathological processes in the brain requires tracking the reversible changes in chemical signals with long-term stability. We developed a new anti-biofouling microfiber array to real-time quantify extracellular Ca2+ concentrations together with neuron activity across many regions in the mammalian brain for 60 days, in which the signal degradation was 2+ upon ischemia-reperfusion processes. The changing sequence and rate of Ca2+ in 7 brain regions were different during the stroke. ROS scavenger could protect Ca2+ influx and neuronal activity after stroke, suggesting the significant influence of ROS on Ca2+ overload and neuron death. We demonstrated this microarray is a versatile tool for investigating brain dynamic during pathological processes and drug treatment.
A Comprehensive Study of the Ca2+ Ion Binding of Fluorescently Labelled BAPTA Analogues
Csomos, Attila,Kontra, Bence,Jancsó, Attila,Galbács, Gábor,Deme, Ruth,Kele, Zoltán,Rózsa, Balázs József,Kovács, Ervin,Mucsi, Zoltán
, p. 5248 - 5261 (2021/10/19)
Since its development, the ionophore BAPTA (1,2-bis(2-aminophenoxy)-ethane-N,N,N’,N’-tetraacetic acid) has been used unchanged in calcium sensing applications. In this work we present a comprehensive experimental and theoretical study of novel alterations in the structure of BAPTA, with a focus on the systematic modification of the chain connecting the two aromatic rings of the molecule (denoted as “linker”). A bis-(diethylamino)xantene fluorophore was also attached to the structures in a fixed position and the structure-fluorescence response relationship of these molecules was investigated in addition. The effect of the linker's length, the number of oxygen atoms in this chain and even the removal of one of the rings was tested; these all proved to significantly alter the characteristics of the compounds. For example, it was found that the second aromatic ring of BAPTA is not essential for the turn-on of the fluorescence. We also demonstrated that successful sensing can be realized even by replacing the chain with a single oxygen atom, which suggests the availability of a new calcium binding mode of the chelator. The reliable turn-on characteristic, the steep Ca2+ fluorescence titration curve and the intense fluorescence emission combine to make this compound a prospective candidate as a calcium sensing molecular probe in diagnostic neurobiological applications.
A Copper Nanocluster-Based Fluorescent Probe for Real-Time Imaging and Ratiometric Biosensing of Calcium Ions in Neurons
Liu, Zhichao,Jing, Xia,Zhang, Sanjun,Tian, Yang
, p. 2488 - 2497 (2019/02/12)
Fluorescent calcium ion (Ca2+) sensing and imaging have become an essential technique for investigation of signaling pathways of Ca2+ and understanding the role of Ca2+ in neurodegenerative disease. Herein a copper nanocluster (CuNC)-based ratiometric fluorescent probe was developed for real-time sensing and imaging of Ca2+ in neurons, in which a specific Ca2+ ligand with two formaldehyde groups was synthesized and further conjugated with polyethylenimine (PEI) to form a new ligand molecule for the synthesis of CuNCs. Meanwhile, water-soluble Alex Fluor 660 NHS ester was immobilized onto CuNCs as a reference element. The developed ratiometric fluorescence nanoprobe demonstrated a good linearity with Ca2+ concentration in the range of 2-350 μM, and a detection limit down to 220 ± 11 nM was achieved. In addition, the response time of the present probe for Ca2+ was found to be less than 2 s with good stability and high selectivity. Taking advantage of the low cytotoxicity and good biocompatibility of the developed nanoprobe, it was discovered that the histamine-induced cytoplasmic Ca2+ increase in various parts of neurons was different. Moreover, it was found O2--induced cytoplasmic Ca2+ burst and O2--induced neuronal death possibly resulted from Ca2+ overload in the neurons.
Water-soluble, redox-active organometallic calcium chelators
Bhattacharyya, Koyel X.,Boubekeur-Lecaque, Le?la,Tapsoba, Issa,Maisonhaute, Emmanuel,Sch?llhorn, Bernd,Amatore, Christian
, p. 14257 - 14264 (2013/04/10)
This paper describes a new series of organometallic water-soluble chelators combining a redox moiety (ferrocene) and a selective Ca2+ chelator (BAPTA) separated by an ethynyl bridge. We report the synthesis and characterization of organometallic derivatives of the BAPTA chelator featuring one (2a) and two ferrocenyl (2b) moieties. Single crystal X-ray structural analysis on these chelators revealed unexpected conformations for the ferrocenyl substituent with respect to the phenyl ring of the BAPTA unit. DFT calculations on a model system of the ferrocenyl-ethynyl-BAPTA molecule were carried out to evaluate the energy separation between the two limiting conformations observed experimentally in the solid state, and to check the effective electronic communication between the binding pocket and the redox probe. The binding affinity of 2a-b for Ca2+, as probed by UV-Vis and cyclic voltammetry, revealed distinct behaviors in the presence of a metal ion depending on whether BAPTA is substituted by one or two ferrocenyl groups.
Discrimination between hard metals with soft ligand donor atoms: An on-fluorescence probe for manganese(II)
Liang, Jian,Canary, James W.
supporting information; scheme or table, p. 7710 - 7713 (2010/12/25)
A backwards strategy for achieving Mn2+/Ca2+ selectivity was demonstrated: Instead of optimizing binding of Mn2+, the bapta ligand (upper structure in scheme) was modified by changing O to N donors to discourage associatio
Ultralow calcium requirements of fungi facilitate use of calcium regulating agents to suppress host calcium-dependent defenses, synergizing infection by a mycoherbicide
Gressel, Jonathan,Michaeli, Daphna,Kampel, Vladimir,Amsellem, Ziva,Warshawsky, Abraham
, p. 6353 - 6360 (2007/10/03)
Infection by many fungi activates a variety of calcium dependent defenses in the hosts, slowing or suppressing the attacker and limiting the efficacy of mycoherbicides. The calcium requirement for fungal growth is so low that it could only be implied based on fungi containing calcium-dependent signaling enzymes. Analytical grade media contain 2 μM calcium, and the addition of specific chelators does not affect fungal growth. Hydrophobic derivatives of the calcium-specific chelator BAPTA designed to traverse plant cuticles were synthesized in order to chelate calcium internally during fungal attack. Some chelators as well as calcium precipitating oxalate and channel blocker verapamil were applied with a weakly mycoherbicidal Colletotrichum coccodes to cotyledons of compatible Abutilon threophrasti. They suppressed calcium dependent callose biosynthesis in the weed and increased virulence but may have affected other calcium-dependent processes that facilitate virulence. The low calcium requirement of fungi, and their high affinity for calcium, allows the application of calcium-regulating agents as synergists for mycoherbicides where the weed uses calcium-dependent defenses.
SYNTHESIS OF BAPTA-AM ANALOGUES CAPABLE OF ENHANCING THE VASCULAR PRODUCTION OF PROSTACYCLIN
Heilporn, S.,Broeders, F.,Daloze, D.,Braekman, J. C.,Boeynaems, J. M.
, p. 309 - 320 (2007/10/02)
About 30 analogues of BAPTA-AM, a potential antithrombotic agent, have been synthesized and tested for their effect on the production of prostacyclin.None of them was found to be a better enhancher of the production of prostacyclin by aortic endothelial cells than BAPTA-AM itself.The enhancing effect can be produced by compounds unable to chelate Ca2+, thus confirming that it is not related to their buffering capacity for free Ca2+.
