Mimetic ligand

Alternatively, binding affinity between the mimetic ligand and receptor might be achieved by a different mechanism than that of the natural ligand. The mimetic ligand might contact a different area of the receptor binding site, or provide a different set of intermolecular interactions. As shown in... 

Ligands selected for HCIC applied to purification of antibodies, exhibit a mild hydrophobic effect, a thiophilic effect and an ionic charge at the ligand head. Table 11 shows some ligands selected for the separation of immunoglobulins by HCIC. HCIC demonstrated its effectiveness to adsorb immunoglobulins of different classes. IgG, IgM were adsorbed on the matrix in similar conditions as per protein A and protein A mimetic ligands, respectively, described in Sections V.F.ii and V.F.x. 

The mechanism of action being similar to the one described for protein A, adsorption was performed in physiological conditions and elution by lowering the pH to 3.8 and below. Contrary to protein A, the described mimetic ligand adsorbed also IgA and IgM binding capacity was reported to be in the range of 4 to 25 mg per milliliter of resin. 

Kabir S. Immunoglobulin purification by affinity chromatography using protein A mimetic ligands prepared by combinatorial chemical synthesis. Immunol. Invest. 2002 31 263-278. 

Chandra and Brown66 investigated the synthesis of x-ribonucleosides as mimetics of the lower axial ligand in coenzyme B12. Reaction of unprotected indolines with... 

Stancovic CJ, Plummer MS, Sawyer TK (1997) Peptidomimetic ligands for src homology-2 domains. In Abell A (ed) Advances in amino acid mimetics and peptidomimetics. Jai Press, Greenwich, vol 1, p 127... 

It was discovered nearly 20 years ago that V(V) as vanadate and V(IV) as vanadyl can mimic some of the effects of insulin (stimulate glucose uptake and oxidation and glycogen synthesis) (512, 513). Vanadate is an effective insulin mimetic in the diabetic rat (514), but has proved to be too toxic for human use. Vanadyl, as VOS04, is also unsuitable because high doses are needed on account of its poor oral absorption. Vanadium complexes with organic ligands have proved to be less toxic and can have improved aqueous solubility and lipophil-icity. 

Among many different complexes that have been synthesized in attempt to mimic the structure and/or functionality of SODs (16-22), the most active SOD mimetics known to date are seven-coordinate Mn(II) complexes with macrocyclic ligands derived from C-substituted pentaazacyclopentadecane [15]aneNs and its pyridine derivative (Scheme 4) (12d,16a,23-25). Some of them possess SOD activity that exceeds the one of native mitochondrial MnSOD, and are the first SOD mimetics which entered clinical trials (12d,16a,23,26-28). A few Fe(III) complexes with the same type of ligands have also been studied and they are one of the best iron-based SOD catalysts (18). It should be stressed that the decomposition of superoxide catalyzed by these complexes has been quantified by direct stopped-fiow method, in the presence of a substantial superoxide excess over catalyst, as a reliable method for determining true SOD activity (29). 

In the case of the Mn(II) SOD mimetics (see earlier), the loss of one water ligand from the seven-coordinate structure is the first step in... 

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