ATPase mimics

An interesting point concerns the reversibility of all of the reaction steps shown in Scheme 12.6. This implies that under certain circumstances, the system might change its behaviour from an ATPase mimic to ATP synthase-type behaviour. This has been achieved through the use of a phosphorylating cofactor, acetyl phosphate (AcP, MeC02P032-). ar,d a divalent metal cation as a promoter (Mg2+ or Ca2+). Under... 

Why do you think corand 4.12 ([24]aneN602) is such an effective ATPase mimic given the discussion of the relatively low affinity for guest species such as alkali metal cations and halide anions set out in Chapters 3 and 4 Similarly, why was a hemispherand chosen as the central cation-binding core of enzyme mimic 12.16 as opposed to a spherand ... 

Hosseini have devoted a lot of effort to aza crown complexes with ATP 48, showing them to be true yet weak ATPase mimics [24], Schmidtchen reported tetrahedral zwitterions 49 to discriminate between spherical anions [25]. Reetz was able to show that ditopic receptor 50, which includes both Lewis-acidic and basic centers will complex a whole ion pair [26]. Incorporation of transition metals into anion receptors such as 51 renders neutral species positively charged and susceptible to spectroscopic and electrochemical manipulations [27]. 

Bencini, A. Bianchi. A. Garcia-Espaiia. E. Scott, E.C. Morales, E. Wang, B. P. Mertes. M. Bowman Mertes. K. Potential ATPase mimics by polyammonium macrocycles Criteria for catalytic activity. Bioorg. Chem. 1992. 20, 8-29. 

Azacrown ethers as enzyme mimics of ATPase 99MI17. 

T1, as the thallous ion (Tl+), has been used for imaging heart function under stress and rest conditions since about 1975. The thallous ion distributes in viable heart muscle as a potassium ion mimic, through the Na+-K+ ATPase pump. Clinical images with 201T1 show the infarcted regions of the heart as cold spots or without radioactivity. 2 T1 decays by electron capture with a... 

A double-carrier membrane system that mimics, in principle, the function of Na, K -ATPase in biological membranes was developed, although chemical compounds involved are completely different (Figure 35). The double-carrier system utilizes dicylohexyl-18-crown-6 (93) and trioctylamine (95) for enhanced transport of K ions from the feed to the receiving solution using picrate ion (pic ) as the pumping ion. The carrier 93 is for uphill transport of using a concentration... 

Sturm E, Kruger U, Senn-Bilfinger J, Figala V, Klemm K, Kohl B, et al. (H+-K+)-ATPase inhibiting 2-[(2-pyridyl-methyl)sulfmyl]benzimidazoles. 1. Their reaction with thiols under acidic conditions. Disulfide containing 2-pyridinio-benzimidazolides as mimics for the... 

Salts of the tetrafluoroaluminate (TFA) anion have been known for many years. Yet aqueous routes to pure materials have not been established despite the substantial amount of literature available on the subject. The present review will discuss the various synthetic methods that have been employed and will demonstrate a revised method for preparing pure TFA salts. These materials are important because TFA is able to stimulate various guanosine nucleotide-binding proteins (G-proteins) and inhibit P-type ATPases by serving as a nonhydrolyzing phosphate mimic. Additionally, various TFA salts serve as precursors to aluminum trifluoride, which is used as a catalyst for chlorofluorocarbon isomerizations and fluorinations. 

---