Affiliation:
1. Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain1
Abstract
Previous work has shown that the avian reovirus cell-attachment sigma C (σC) protein is a multimer. In the first part of this study the oligomerization state of intracellularly synthesized σC was analysed by different approaches, including SDS–PAGE, chemical cross-linking, sedimentation and gel filtration analysis. All these approaches indicated that protein σC in its native state is a homotrimer. In the second part of the present work we investigated the effect of different factors and reagents on oligomer stability, in order to elucidate the nature of the forces that maintain the conformational stability of the homotrimer. Our results, based on the stabilizing effect conferred by reducing agents, demonstrate that the σC subunits are not covalently bound via disulfide linkages. They further suggest that the formation of an intrachain disulfide bond between the two cysteine residues of the σC polypeptide has a negative effect on oligomer stability. The susceptibility of the trimer to pH, temperature, ionic strength, chemical denaturants and detergents indicates that hydrophobic interactions contribute much more to oligomer stability than do ionic interactions and hydrogen bonding. Finally, our results also reveal that mammalian and avian reovirus cell attachment proteins follow different subunit dissociation pathways.
Reference41 articles.
1. Evidence that the sigma 1 protein of reovirus serotype 3 is a multimer;Bassel-Duby;Journal of Virology,1987
2. Increase in acid-binding sites on denaturation of horse ferrihemoglobin at 0 °C;Beychok;Journal of the American Chemical Society,1959
3. Reassembly of a large multisubunit protein promoted by nonprotein factors. Effects of calcium and glycerol on the association of extracellular hemoglobin;Bonafe;Journal of Biological Chemistry,1991
4. Structural dynamics of the Streptomyces lividans K+ channel (SKC1): oligomeric stoichiometry and stability;Cortes;Biochemistry,1997
5. Reversible dissociation and unfolding of dimeric creatine kinase isoenzyme MM in guanidine hydrochloride and urea;Couthon;European Journal of Biochemistry,1995
Cited by
30 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献