A heat denaturation study of several ribosomal proteins from escherichia coli by scanning microcalorimetry

Compact globular structure of protein S15 from Escherichia coli ribosomes

“…A previous heat denaturation study of our prepara- tion of protein S15 has demonstrated the cooperativity and high thermal stability (tk = 72°C) of its tertiary structure [28], which is consistent with a compact globular state of the protein molecule in solution.…”

“…It is seen that the ratio between the radius of gyration and the molecular weight of protein S15 corresponds fully to a compact globular protein. For comparison, the results of neutron scattering for the dimer of protein L7 which seems to have a rod-like or dumbbell-like structure [25-271 and for protein S18 in the form of a partly disordered polypeptide chain ( [28], Z.V.G., S.Yu.V., unpublished) are also plotted in fig.5. …”

Study of the secondary and tertiary structure of ribosomal protein S7 from Escherichia coli in solution

“…The small radius of gyration of protein S7, about 15 A [S], directly indicated the presence of a compact globular structure. Preliminary scanning microcalorimetric experiments testified to the presence of a cooperative tertiary structure in this protein [8]. Here we report circular dichroism and nuclear magnetic resonance spectra of protein S7 in solution.…”

“…Thus, in the presence of 2 M urea it is already practically disrupted (fig.3A). Microcalorimetric data indicate a rather low melting temperature of this protein in solution, near 40-45°C [8].…”

Cloning, purification and characterization of the ribosomal protein L11 from E. coli

“…At temperatures higher than 37˚C the protein L11 is aggregating because of denaturation, increasing with the concentration of protein and decreasing with the salt concentration up to 1 M. The reported thermal denaturation of protein L11 showed low thermostability with a transition of about 50˚C. The aggregation appeared after the middle of the transition, but the existence of a peak is evidence of a cooperative structure [6]. The process was irreversible and an enthalpy of denaturation could not be calculated.…”