Macromolecular sites activity

Macromolecular Sites of Activity for the Trichothecenes. All the trichothecenes tested act, in eukaryotic systems, at the site of the 60s ribosome subunit and specifically inhibit peptidyl transferase. However, the trichothecenes are divided into two specific classes relative to this activity and are either initation inhibitors or elongation and/or termination inhibitors. The initiation inhibitors ares 15-acetoxyscirpen-diol 4-acetylnivalenol diacetoxyscirpenol HT-2 toxin nivalenol T-2 toxin scirpentriol verrucarin A (4-0, 11b). 

A novel method has been proposed [203-205] for obtaining polymeric sorbents with prearranged macromolecular sites for complexing with transition metal ions. Cobalt complexes with the prearranged sorbent were tested as catalysts by the liquid-phase oxidation of styrene and ethylbenzene. These catalysts could be used repeatedly without a decrease in activity. The catalytic activity of polyacrylonitrile and polypropargyl methacrylate complexes with Co was studied during ethylbenzene oxidation reactions [206, 207]. 

Quantum mechanics is essential for studying enzymatic processes [1-3]. Depending on the specific problem of interest, there are different requirements on the level of theory used and the scale of treatment involved. This ranges from the simplest cluster representation of the active site, modeled by the most accurate quantum chemical methods, to a hybrid description of the biomacromolecular catalyst by quantum mechanics and molecular mechanics (QM/MM) [1], to the full treatment of the entire enzyme-solvent system by a fully quantum-mechanical force field [4-8], In addition, the time-evolution of the macromolecular system can be modeled purely by classical mechanics in molecular dynamicssimulations, whereas the explicit incorporation... 

Arya et al. used solid phase synthesis to prepare immobilised dendritic catalysts with the rhodium centre in a shielded environment to mimic nature s approach of protecting active sites in a macromolecular environment (e.g. catalytic sites inside enzymes) [51], Two generations PS immobilised rhodium-complexed dendrimers, 6 and the more shielded 7, were synthesised.The PS resin immobilised rhodium-complexed dendrimers were used in the hydroformylation of styrene, p-methoxystyrene, vinyl acetate and vinyl benzoate using a total pressure of 70 bar 1 1 CO/H2 at 45 °C in CH2C12. 

According to the U.S. National Nanotechnology Institute, nanotechnology encompasses research and development to synthesize, control, and manipulate stmctures, devices, and systems of novel properties and functions because of their size at the atomic, molecular, or macromolecular levels in the length scale ranging from approximately 1 to 100 nanometers. Indeed, this length scale is of particular relevance to heterogeneous catalysis, where the active sites are small crystallites or domains of the active phase. The reaction typically involves atom-molecule interactions, and the active sites are placed in or on an extended solid where the access paths to the active sites are tens to hundreds of nanometers. The issue of access path is a familiar territory in... 

Ciclopirox olamine is a synthetic broad-spectrum antimycotic agent with inhibitory activity against dermatophytes, Candida species, and P orbiculare. This agent appears to inhibit the uptake of precursors of macromolecular synthesis the site of action is probably the fungal cell membrane. 

The entire iron-porphyrin-protein complex is called a cytochrome and such proteins are important electron-transfer components of cells. Generally, access to the macromolecular region in which the oxidation reactions occur is via a hydrophobic channel through the protein (Mueller et al., 1995). As a result, organic substrates are transferred from aqueous solution into the enzyme s active site primarily due to their hydrophobicity and are limited by their size. This important feature seems very appropriate hydrophobic molecules are selected to associate with this enzyme, and these are precisely the ones that are most difficult for organisms to avoid accumulating from a surrounding aquatic environment. 

Many studies on the cationic trypanocides have failed to identify their site(s) of action. A recent proposal is that their activity is due to interaction with biologically active polyamines, e.g. spermine and spermidine (80MI10809). These and other polyamines have significant roles in cell division and macromolecular synthesis. 

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