scholarly journals Contemplating 1,2,4-Thiadiazole-Inspired Cyclic Peptide Mimics: A Computational Investigation

2019 ◽  
Vol 72 (11) ◽  
pp. 894 ◽  
Author(s):  
Sida Xie ◽  
Paul V. Bernhardt ◽  
Lawrence R. Gahan ◽  
Craig M. Williams

Marine derived cyclic peptides have inspired chemists for decades as the cavitand architecture can be compared with macrocyclic ligands, and hence easily conceived as mediators of metal-ion transport. Lissoclinamide 5 and ascidiacyclamide are two such cyclic peptides that have received much attention both for their metal ion complexation properties and biological activity; the metal ion binding properties of mimics of these two systems have been reported. Reported herein is a computational study aimed at evaluating the stability, and potential for copper(ii) ion binding by lissoclinamide 5 mimics that substitute the naturally occurring 4-carboxy-1,3-thiazole units for novel valine- and phenylalanine-derived 1,2,4-thiadiazole units. Our results suggest that one lissoclinamide 5 mimic, 1,2,4-thiadiazole (TDA)-lissoclinamide 9, may be capable of forming a complex with one CuII ion, [Cu(9-H)(H2O)]+. A complex with two CuII ions, [Cu2(9-H)(μ-OH)]2+, was also considered. These results set the stage for synthetic and experimental metal binding studies.

RSC Advances ◽  
2016 ◽  
Vol 6 (91) ◽  
pp. 88010-88029 ◽  
Author(s):  
Gunjan Agarwal ◽  
Dipali N. Lande ◽  
Debamitra Chakrovarty ◽  
Shridhar P. Gejji ◽  
Prajakta Gosavi-Mirkute ◽  
...  

Bromine substituted aminonaphthoquinones – chemosensors for metal ions.


2005 ◽  
Vol 44 (22) ◽  
pp. 8105-8115 ◽  
Author(s):  
Abel Tamayo ◽  
Carlos Lodeiro ◽  
Lluis Escriche ◽  
Jaume Casabó ◽  
Berta Covelo ◽  
...  

1999 ◽  
Vol 6 (6) ◽  
pp. 321-328 ◽  
Author(s):  
Bin Song ◽  
Jing Zhao ◽  
Fridrich Gregáň ◽  
Nadja Prónayová ◽  
S. Ali A. Sajadi ◽  
...  

The stability constants of the 1:1 complexes formed between methylphosphonylphosphate (MePP3-), CH3P(O)2--O-PO32- , and Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+,​ or Cd2+ (M2+) were determined by potentiometric pH titration in aqueous solution (25 C° ; l = 0.1 M, NaNO3 ). Monoprotonated M(H;MePP) complexes play only a minor role. Based on previously established correlations for M2+ -diphosphate monoester complex-stabilities and diphosphate monoester β-group. basicities, it is shown that the M(Mepp)- complexes for Mg2+ and the ions of the second half of the 3d series, including Zn2+ and Cd2+, are on average by about 0.15 log unit more stable than is expected based on the basicity of the terminal phosphate group in MePP3-. In contrast, Ba(Mepp)- and Sr(Mepp)- are slightly less stable, whereas the stability for Ca(Mepp)- is as expected, based on the mentioned correlation. The indicated increased stabilities are explained by an increased basicity of the phosphonyl group compared to that of a phosphoryl one. For the complexes of the alkaline earth ions, especially for Ba2+, it is suggested that outersphere complexation occurs to some extent. However, overall the M(Mepp)- complexes behave rather as expected for a diphosphate monoester ligand.


1987 ◽  
Vol 33 (3) ◽  
pp. 405-407 ◽  
Author(s):  
R B Martin ◽  
J Savory ◽  
S Brown ◽  
R L Bertholf ◽  
M R Wills

Abstract An understanding of Al3+-induced diseases requires identification of the blood carrier of Al3+ to the tissues where Al3+ exerts a toxic action. Quantitative studies demonstrate that the protein transferrin (iron-free) is the strongest Al3+ binder in blood plasma. Under plasma conditions of pH 7.4 and [HCO3-]27 mmol/L, the successive stability constant values for Al3+ binding to transferrin are log K1 = 12.9 and log K2 = 12.3. When the concentration of total Al3+ in plasma is 1 mumol/L, the free Al3+ concentration permitted by transferrin is 10(-14.6) mol/L, less than that allowed by insoluble Al(OH)3, by Al(OH)2H2PO4, or by complexing with citrate. Thus transferrin is the ultimate carrier of Al3+ in the blood. We also used intensity changes produced by metal ion binding to determine the stability constants for Fe3+ binding to transferrin: log K1 = 22.7 and log K2 = 22.1. These constants agree closely with a revision of the reported values obtained by equilibrium dialysis. By comparison with Fe3+ binding, the Al3+ stability constants are weaker than expected; this suggests that the significantly smaller Al3+ ions cannot coordinate to all the transferrin donor atoms available to Fe3+.


2017 ◽  
Vol 37 (2) ◽  
Author(s):  
Gunseli Bayram Akcapinar ◽  
Osman Ugur Sezerman

Metal ions play pivotal roles in protein structure, function and stability. The functional and structural diversity of proteins in nature expanded with the incorporation of metal ions or clusters in proteins. Approximately one-third of these proteins in the databases contain metal ions. Many biological and chemical processes in nature involve metal ion-binding proteins, aka metalloproteins. Many cellular reactions that underpin life require metalloproteins. Most of the remarkable, complex chemical transformations are catalysed by metalloenzymes. Realization of the importance of metal-binding sites in a variety of cellular events led to the advancement of various computational methods for their prediction and characterization. Furthermore, as structural and functional knowledgebase about metalloproteins is expanding with advances in computational and experimental fields, the focus of the research is now shifting towards de novo design and redesign of metalloproteins to extend nature’s own diversity beyond its limits. In this review, we will focus on the computational toolbox for prediction of metal ion-binding sites, de novo metalloprotein design and redesign. We will also give examples of tailor-made artificial metalloproteins designed with the computational toolbox.


2014 ◽  
Vol 33 (18) ◽  
pp. 4873-4887 ◽  
Author(s):  
Bimalendu Adhikari ◽  
Alan J. Lough ◽  
Bryan Barker ◽  
Afzal Shah ◽  
Cuili Xiang ◽  
...  

1988 ◽  
Vol 66 (5) ◽  
pp. 1194-1198 ◽  
Author(s):  
Oswald S. Tee ◽  
N. Rani Iyengar

Bromide ion induced debromination of the anion of 4-bromo-4-methyl-2,5-cyclohexadienone-2-carboxylic acid (1) is catalyzed by cupric ions and ferric ions. Similarly, the enolization of the anion of the benzocyclohexadienone 3, which is formed during the bromination of 1-naphthol-2-carboxylic acid, is catalyzed by some metal ions. The origin of the catalysis in these reactions is strong metal ion binding to the incipient dianion products that are of the salicylate type. Evidence for this is that the efficiency of the metal (and hydrogen) ion catalysis parallels the stability of the analogous complexes with the salicylate dianion.


1988 ◽  
Vol 42 (2) ◽  
pp. 293-295 ◽  
Author(s):  
E. K. L. Wong ◽  
G. L. Richmond

The metal ion binding properties of the perfluorosulfonate membrane Nafion® have been investigated in this study. The experiments involve laser-induced fluorescence measurements of europium (III) ions which are bound to the membrane. By the exploitation of the hypersensitivity of the D → F transitions of europium (III) to the ligand binding environment, the properties of the metal binding sites have been analyzed as a function of various experimental parameters. The spectra and fluorescence lifetime measurements provide evidence for distinct metal binding sites within the polymer, each of which is sensitive to the conditions of the membrane preparation.


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