Protein folding diffusion-collision model

Karplus M. and Weaver D. L. Protein-folding dynamics - the diffusion-collision model and experimental-data. Prot. Sri. (1994) 3(4) 650-668. 

The other explanation is the diffusion-collision model in which the secondary structure forms very fast [5,17]. These secondary structure elements then diffuse in a random walk fashion until they collide in the proper way and form the tertiary structure. Islam et al. used this model to analyze the folding of a three helix bundle proteins [17]. 

S. Islam, M. Karpins, D. Weaver (2002) Application of the diffusion-collision model to the folding of three-helix bundle proteins. J. Mol. Biol. 318, pp. 199-215... 

S. Y. Lee, M. Karplus, D. Bashford, and D. Weaver, Biopolyrners, 26,481 (1987). Brownian Dynamics Simulation of Protein Folding A Study of the Diffusion-Collision Model. 

In the diffusion-collision model of protein folding, the kinetics of microdomains with inherent structure-forming... 

The diffusion-collision model proposed by Karplus and Weaver (1976) as well as the approaches mentioned previously assumes a folding by steps, based on the formation of several microdomains which associate to form larger structures which on turn associate and so on. The formation of such microstructures would permit one to understand how nature had worked during the early stages of evolution for building a protein from elementary pieces with a given function and also what kind of assembly of these building blocks were necessary to differentiate. 

It is likely that conformational fluctuations also have an important role in protein folding. Fluctuations are certainly less restricted in the unfolded form than in the native one. Their role is particularly emphasized in the diffusion-collision model. 

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