RESUMO
The mechanism of alpha-->beta transition in folding of beta-lactoglobulin is discussed based on free energy landscape analysis of a long lattice model. It is found that helical propensity of beta-lactoglobulin is driven by conformational entropy and is intrinsically coded in its native structure. We propose a view on a role of folding intermediate, which is "on-pathway" but rich in non-native structures. The present results suggest that the native structure topology plays an important role in alpha-->beta transition.
Assuntos
Lactoglobulinas/química , Dobramento de Proteína , Simulação por Computador , Transferência de Energia , Modelos Moleculares , Método de Monte Carlo , Estrutura Secundária de ProteínaRESUMO
We examined what determines the designability of two-letter codes (H and P) lattice proteins from three points of view. First, whether the native structure is searched within all possible structures or within maximally compact structures. Second, whether the structure of the used lattice is bipartite or not. Third, the effect of the length of the chain, namely, the number of monomers on the chain. We found that the bipartiteness of the lattice structure is not a main factor that determines the designability. Our results suggest that highly designable structures will be found when the length of the chain is sufficiently long to make the hydrophobic core consisting of a large enough number of monomers.
