The 1-hydroxy-1-methyl-6,6-diphenyl-5-hexenyl radical (4a) and the 1-hydroxy-1-methyl-7,7-diphenyl-6-heptenyl radical (4b) were prepared from the corresponding PTOC esters (anhydrides of a carboxylic acid and N-hydroxypyridine-2-thione). The key step in the synthetic method for the precursors was a coupling reaction of the respective carboxylic acids with the thiohydroxamic acid, which was cond...

The successive estimation of regression parameters is an effective technique applied in nonlinear regression analysis. In the paper, this method is used for obtaining kinetic information from spectral data without any pure component spectra. In order to study the way kinetics may be determined by ‘hard’ model without separate calibration, the simulated example of a two-step reaction was constru...

When estimating rate constants using the BIAcore surface plasmon resonance (SPR) biosensor, one must have an accurate mathematical model to interpret sensogram data. Several models of differing complexity are discussed, including the effective rate constant (ERC) approach. This model can be shown formally to be good within O(Da) in the limit of small Damköhler number Da, which is the ratio of t...

In an experimental study of single enzyme reactions, it has been proposed that the rate constants of the enzymatic reactions fluctuate randomly, according to a given distribution. To quantify the uncertainty arising from random rate constants, it is necessary to investigate how one can simulate such a biochemical system. To do this, we will take the Gillespie’s stochastic simulation algorithm f...

MOTIVATION Scale-free networks have had a profound impact in Biology. Network theory is now used routinely to visualize, navigate through, and help understand gene networks, protein-protein interactions, regulatory networks and metabolic pathways. Here we analyse the numerical rather than topological properties of biological networks and focus on the study of kinetic rate constants within pathw...

Evolutionary conservation of protein interaction properties has been shown to be a valuable indication for functional importance. Here we use homology interface modeling of 10 Ras-effector complexes by selecting ortholog proteins from 12 organisms representing the major eukaryotic branches, except plants. We find that with increasing divergence time the sequence similarity decreases with respec...