Contribuição ao estudo do efeito de solventes desnaturantes sobre o espectro ultravioleta e a mobilidade Eletroforética de proteínas ou cromóforos modelos de proteínas

Abstract

Protein cooperativism is an extremely important process. It is the basis of allosteric mechanisms of protein activity regulation, but it also manifests itself in processes such as the unfolding of three-dimensional protein structures and can be expressed at population levels of partially folded intermediate states during the transition from native to unfolded state. (Freire et al., 1992). The theory, characteristics and properties of cooperative transitions are developed with reference to the abrupt changes that occur in protein solutions (Lumry et al., 1966). The biological activity of proteins requires a highly ordered three-dimensional structure. In folding techniques, activity represents a very sensitive criterion because of the relationship between protein structure and function (Jaenicke, 1989 apud Yoshida et al., 1993). Since a large number of conformations are possible for a polypeptide chain, obtaining A native structure through a random mechanism is not a satisfactory model (Vanhove, 1995). The mechanism by which the polypeptide chain directs folding to its native conformation is a fundamental problem that remains unresolved and has been elucidated by Physical Biochemistry (Denton et al., 1994; Matthews et al., 1981). In due course, the identification of intermediaries is supported by the highly cooperative nature of the folding process. 1 (Kuwajima et al., 1989; Gorovits et al., 1995). A wide variety of experimental techniques have been used to try to overcome these difficulties and clarify the protein folding mechanism (Kim & Baldwin, 1990; Yoshida et al., 1993) including mutational studies (Jennings et al., 1991) masking studies. disulfide bonding (Creigthon, 1986; Weissmam & Kim, 1991) studies of partially and thermodynamically stable bent species (Kuwajima, 1989) and model peptide studies (Oas & Kim, 1988; Montelione & Scheraga, 1989). The methodology for discovering the individual folding steps comprises thermodynamics and kinetic analysis of the refolding processes. unfolding.