title: Independent of their localization in protein the hydrophobic amino acid residues have no effect on the molten globule state of apomyoglobin and the disulfide bond on the surface of apomyoglobin stabilizes this intermediate state.
abstract: At present it is unclear which interactions in proteins reveal the presence of intermediate states, their stability and formation rate. In this study, we have investigated the effect of substitutions of hydrophobic amino acid residues in the hydrophobic core of protein and on its surface on a molten globule type intermediate state of apomyoglobin. It has been found that independent of their localization in protein, substitutions of hydrophobic amino acid residues do not affect the stability of the molten globule state of apomyoglobin. It has been shown also that introduction of a disulfide bond on the protein surface can stabilize the molten globule state. However in the case of apomyoglobin, stabilization of the intermediate state leads to relative destabilization of the native state of apomyoglobin. The result obtained allows us not only to conclude which mutations can have an effect on the intermediate state of the molten globule type, but also explains why the introduction of a disulfide bond (which seems to "strengthen" the protein) can result in destabilization of the protein native state of apomyoglobin.
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia.
authors.forename: Tatiana N
authors.initials: TN
authors.lastname: Melnik
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Majorina
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia.
authors.forename: Daria S
authors.initials: DS
authors.lastname: Larina
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Kashparov
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia; Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: Ekaterina N
authors.initials: EN
authors.lastname: Samatova
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia.
authors.forename: Anatoly S
authors.initials: AS
authors.lastname: Glukhov
authors.affiliation: Institute of Protein Research, RAS, Pushchino, Moscow Region, Russia.
authors.forename: Bogdan S
authors.initials: BS
authors.lastname: Melnik
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001059:Apoproteins / Q000737:chemistry* / Q000235:genetics; D004220:Disulfides / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009154:Mutation; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary
chemical_list: D000596:Amino Acids; D001059:Apoproteins; D004220:Disulfides; D009211:Myoglobin; C010857:apomyoglobin