Irreversible aggregate formation, kinetics

Hence, the performed above analysis has shown that different solvents using in low-temperature nonequilibriiun polycondensation process can result not only in symthesized polymer quantitative characteristics change, but also in reaction mechanism and polymer chain structure change. This effect is comparable with the observed one at the same polymer receiving by methods of equilibrium and nonequilibrium polycondensation. Let us note, that the fractal analysis and irreversible aggregation models allow in principle to predict symthesized polymer properties as a function of a solvent, used in synthesis process. The stated above results confirm Al-exandrowicz s conclusion [134] about the fact that kinetics of branched polymers formation effects on their topological structures distribution and macromolecules mean shape. 

Ernst, M. H. Kinetics of cluster formation at irreversible aggregation. In book Fractals in Physics. Ed Pietronero, L. Tosatti, E. Amsterdam, Oxford, New York, Tokyo, North-Holland, 1986, 399-429. 

It is now well understood that fibril formation requires conformational changes, but the assembly steps may differ from one system to another (Kelly, 1998). For example, aggregation into well-ordered structures occurs in multiple steps during the formation of /Mactoglobulin fibrils. First, there is a fast and reversible step followed by an irreversible step involving the formation of nonreversible /1-sheet structures (Arnaudov et al., 2003). Interestingly, the reversible step, which corresponds to a lag in fibril formation, varies from one system to another and most likely depends on the specific kinetic partitioning between the misfolded intermediate and the native state (Dobson, 1999 Jaenicke, 1995 Uversky, 2003). 

With the M4 isoenzyme, a single irreversible bimolecular process was sufficient to describe the kinetics of reactivation (Rudolph and Jaenicke, 1976). Competition between reactivation and formation of aggregates has been particularly well studied for this enzyme. The aggregates have been analyzed and their reactivation has been achieved after previous degradation by 6 M GuHCl (Zeittlmeissl et a/., 1979a,b Rudolph et a/., 1979). 

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