Adenine is formed in about 18% yield when HCN tetramer is heated with ammonium formate at 110 degrees C. The prebiotic significance of this reaction is discussed.
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http://dx.doi.org/10.1023/a:1016070723772 | DOI Listing |
J Chem Inf Model
June 2024
Department of Biology, Computational Biology & Simulation, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany.
Hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels are opened in an allosteric manner by membrane hyperpolarization and cyclic nucleotides such as cAMP. Because of conflicting reports from experimental studies on whether cAMP binding to the four available binding sites in the channel tetramer operates cooperatively in gating, we employ here a computational approach as a promising route to examine ligand-induced conformational changes after binding to individual sites. By combining an elastic network model (ENM) with linear response theory (LRT) for modeling the apo-holo transition of the cyclic nucleotide-binding domain (CNBD) in HCN channels, we observe a distinct pattern of cooperativity matching the "positive-negative-positive" cooperativity reported from functional studies.
View Article and Find Full Text PDFFront Physiol
August 2022
Universitätsklinikum Jena, Institut für Physiologie II, Jena, Germany.
Hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels are tetramers that generate electrical rhythmicity in special brain neurons and cardiomyocytes. The channels are activated by membrane hyperpolarization. The binding of cAMP to the four available cyclic nucleotide-binding domains (CNBD) enhances channel activation.
View Article and Find Full Text PDFPolymers (Basel)
August 2022
Instituto Nacional de Técnica Aeroespacial "Esteban Terradas" (INTA), Ctra. Torrejón-Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain.
The polymers based on diaminomaleonitrile (DAMN polymers) are a special group within an extensive set of complex substances, namely HCN polymers (DAMN is the formal tetramer of the HCN), which currently present a growing interest in materials science. Recently, the thermal polymerizability of DAMN has been reported, both in an aqueous medium and in bulk, offering the potential for the development of capacitors and biosensors, respectively. In the present work, the polymerization of this plausible prebiotic molecule has been hydrothermally explored using microwave radiation (MWR) via the heating of aqueous DAMN suspensions at 170-190 °C.
View Article and Find Full Text PDFJ Org Chem
August 2021
Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany.
An efficient, inexpensive, and reliable synthesis of diaminomaleonitrile (DAMN, ) is described starting from readily available acetone cyanohydrin as the source of hydrogen cyanide (HCN). Diaminomaleonitrile (DAMN) is known to be an important intermediate in heterocyclic and medicinal chemistry as well as being a possible precursor for the origin of life's hypothesis within prebiotic chemistry. The mechanism of its formation through organosulfur catalysis has been investigated by electrospray ionization mass spectrometry (ESI-MS) using two newly synthesized cationic "marker" molecules as a tool that allows for sensitive detection.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2020
Department of Molecular Sensory Systems, Research Center Caesar, 53175 Bonn, Germany;
Proton (H) channels are special: They select protons against other ions that are up to a millionfold more abundant. Only a few proton channels have been identified so far. Here, we identify a family of voltage-gated "pacemaker" channels, HCNL1, that are exquisitely selective for protons.
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