Moulding calixarenes for biomacromolecule targeting

Fostering protein–calixarene interactions: from molecular recognition to sensing

An highly selective direct sensing of cytochrome c by a bis-calix[4]arene-carbazole conjugate (CCC-1) in aqueous-based medium at nanomolar levels is disclosed. An electron transfer (ET) between complexed partners mediates the sensory event.

Cyclodextrin-based facial amphiphiles: assessing the impact of the hydrophilic–lipophilic balance in the self-assembly, DNA complexation and gene delivery capabilities

Precise tailoring of cationic and lipophilic domains of cyclodextrin-based amphiphiles permits the control of their self-assembling and gene delivery capabilities.

“Clickable” thiacalix[4]arene derivatives bearing polymerizable 1,3-butadiyne fragments: synthesis and incorporation into polydiacetylene vesicles

Thiacalix[4]arene-functionalized polydiacetylene (PDA) vesicles showed selective colorimetric response toward several lanthanide ions. This approach can be a good basis for lanthanide express analysis.

CALIX[4]ARENES AS MODULATORS OF ENERGY-DEPENDENT CA2+_ACCUMULATION AND FUNCTIONING OF THE ELECTRON TRANSPORT CHAIN IN SMOOTH MUSCLE MITOCHONDRIA

The influence of supramolecular macrocyclic compounds calix[4]arenes (C-97, C-99, C-107) at a concentration of 100 nM in the process of energy-dependent Ca²⁺-transport in isolated mitochondria of smooth muscle, as well as autofluorescence mitochondrial coenzyme NADH, FAD and hydrodynamic diameter of these organelles was investigated. Using Ca²⁺-sensitive fluorescent dye Fluo-4 AM it was shown that the selected calix[4]arenes can suppress energy-dependent accumulation of Ca²⁺ by mitochondria. Accumulation of Ca²⁺ (80 jiM in the medium) accompanied by the growth of the fluorescent probe response from a conventional unit to a value of 1,57±0,04 (n=5). Calix[4]arenes C-97, C-99, C-107 falls fluorescent signal below the 0,88±0,08, 0,92±0,08 and 0,78±0,04 respectively. Thus, the selected calix[4]arenas lead to release of previously accumulated Ca2+ from mitochondria. Under the influence of C-97 and C-99 fluorescent signal from NADH reduced to -0,11±0,02 and -0,12±0,02, respectively, in relation to the reference value - -0,05±0,01 (n=5). Analysis of fluorescence response NADH and FAD in a suspension of isolated mitochondria suggests that the effects of test compounds on the functional activity of the electron transport chain is associated with the initial stimulation of its 1-th complex and subsequent inhibition of Ca²⁺-dependent NAD- containing Krebs cycle dehydrogenases. Along with this, the use of photon correlation spectroscopy to assess changes in the volume of mitochondria (their hydrodynamic diameter) under the action of selected calix[4]arenes has shown that interference with the electron transport chain leads to changes in the osmotic balance between the matrix of the mitochondria and the external environment. The result is the growth of isolated organelles volume. In particular, the hydrodynamic diameter of mitochondria increased by 22±6 % and 34±8 % (n=5) in presence of C-97 or C-99. The conclusion was done about the advisability of further studies of the calyx[4]arenes effect on smooth muscle Ca²⁺-homeostase and mitochondrial bioenergetics in order to find effective modifiers of their func- tional activity.