Polyoxometalates as Versatile Enzyme Inhibitors

Abstract

Keywords: Cluster compounds / Polyoxometalates / Metalloprotein mimics / Enzymes / Inhibitors / Bioinorganic chemistryPolyoxometalates (POMs) are inorganic cluster compounds that have been shown to possess a number of pharmacological properties, including antidiabetic, antibacterial, antiprotozoal, antiviral and anticancer activities. Their molecular mechanism of action is largely unknown. However, several studies indicate that many of their activities may be due to the inhibition of enzymes, in particular, of those enzymes that are accessible from the extracellular space and do not require the penetration of cell membranes. In this review, we describe the recent progress in the preparation and optimiza-[a] Institute

Simulating the Favorable Aggregation of Monolacunary Keggin Anions

“…Thus, the unequivocal formation of aggregates in 3-A and 3-B ( Figure 9 and Figure 10), recognisable in the distance plots in Figure 8, strongly implies that aggregates in 2-A and 2-B too only form because of 2's -9 charge. Turning once again to the 2013 studies by Chaumont and Wipff, 69 Even if it concerns species with much lower charges, this observation is still very much in line with our own, and somewhat reinforces our hypothesis that, all else being equal in our particular study, the -9 charge on [AlW 11 O 39 ] 9-is the main factor driving its aggregation.…”

“…As early as 1933, 2 working with X-ray diffraction and the anion [PW 12 O 40 ] 3-, Keggin was able to resolve the characteristic tetrahedral structure of PKAs in their α-form ( Figure 1a): a central tetrahedron [XO 4 ], surrounded by a [M 12 O 40 ] outer cage, wherein each of the metal atoms is coordinated by six oxygen atoms (one always coming from the central [XO 4 ]). Monolacunary Keggin anions (MKAs), on the other hand, have general formula [XM 11 O 39 ] (q+r)-, and were only first reported almost a century and a half later: 3 with respect to PKAs, they are formally missing one [M=O] r+ unit from their outer cage, which is replaced by a rectangular [O 4 ] lacuna (Figure 1b). Aside from lowering overall symmetry and charge, the lacuna introduces a large dipole moment, which is perpendicular to its own plane (cf.…”

“…Aside from lowering overall symmetry and charge, the lacuna introduces a large dipole moment, which is perpendicular to its own plane (cf. Figure 2 for [AlW 11 O 39 ] 9-; vide infra).…”

“…PKAs and MKAs of varying atomic composition are currently known for a series of highly desirable chemical characteristics, all comprehensively documented: 4, 5 these comprise their prominent redox and catalytic activity; 6 their magnetic behaviour; 7,8 as well as applications in sensing, 9 biology, 10,11 and optoelectronics. 12,13 In addition, the rectangular lacuna in MKAs represents an ideal binding site wherein to anchor a variety of functional moieties and/or linkers: [14][15][16][17] in practice, this somewhat broadens MKAs' versatility with respect to that of PKAs.…”

Molecular Origin of the Hydrolytic Activity and Fixed Regioselectivity of a ZrIV‐Substituted Polyoxotungstate as Artificial Protease

“…The first type of activity covers the field of viral infections, [8] a second type is related to their use as antitumor agents [9] and the third type of activity is found in the area of bacterial infections. [10] The biological activity of POMs has been studied extensively and either their redox activity [11] or their interaction with biomolecules [7,12] has been proposed as the basic mechanism of their biological action. Subsequent studies have focused on the molecular understanding of POM interactions with proteins, [5h, 13] however, reactivity was not reported in any of these studies.…”