Characterization of an associated equilibrium folding intermediate of bovine growth hormone

摘要: In the preceding paper [Havel, H. A., Kauffman, E. W., Plaisted, S. M., & Brems, D. N. (1986) Biochemistry (preceding in this issue)], an associated intermediate was shown to be highly populated during equilibrium denaturation of bovine growth hormone. paper, we describe its partial characterization and propose a mechanism for association. The is under conditions that induce at protein concentrations greater than 0.2 mg/mL. remaining nativelike helical structure present partially denatured species implicated association as demonstrated by similar concentration dependencies thermal stabilities helix intermediate. Furthermore, it suggested putative amphiphilic from residues 110-127 plays critical role diminution when mixed with peptide fragment 96-133. A model proposed account these results which exposes segment corresponding hydrophobic face 110-127. This metastable form occurs. Association stabilized interactions resulting intermolecular packing lipophilic faces helices. implications folding studies are described.