Inside of the burst-phase intermediate of a protein folding. Hydration of hydrophobic groups.

The thermal effect of the formation of the "burst-phase" folding intermediate has been studied using a titration calorimeter. It is shown that, unlike the total thermal effect of native structure formation, it can be both positive and negative depending on the temperature. The reasons for this paradoxical behavior are analyzed.

Dependence on acyl chain length of energy and volume parameters of the gel to liquid-crystalline transition of 1,2-diacylphosphatidylcholines. Theoretical consideration.

The effect of acyl chain length on energy and volume parameters of gel to liquid-crystal transitions in phospholipids is analyzed. It is demonstrated that simple structural and thermodynamic considerations allow predicting some thermodynamic and volume characteristics of transitions and their dependencies on the acyl chains length.

Thermodynamic invariants of gel to the liquid-crystal 1,2-diacylphosphatidylcholines transition.

The bilayer phase transitions from the ripple gel phase (P'(β)) to the liquid-crystal phase (L(α)) of a series of 1,2-diacylphosphatidylcholines containing a linear saturated acyl chain (C=14-19) have been studied by high-pressure scanning microcalorimetry. It has been shown that at ambient pressure, the transition temperature increases non-linearly depending on the acyl chain length. Pressure stabilizes the gel phase of lipids in a similar way; the pressure derivatives of the logarithm transition temperature as function of pressure are identical for all lipids.

Kinetics and thermodynamics of the unfolding and refolding of the three-stranded alpha-helical coiled coil, Lpp-56.

Temperature-induced reversible unfolding and refolding of the three-stranded alpha-helical coiled coil, Lpp-56, were studied by kinetic and thermodynamic methods, using CD spectroscopy, dynamic light scattering, and scanning calorimetry. It was found that both unfolding and refolding reactions of this protein in neutral solution in the presence of 100 mM NaCl are characterized by unusually slow kinetics, which permits detailed investigation of the mechanism of these reactions. Kinetic analyses show that the unfolding of this coiled coil represents a single-stage first-order reaction, while the refolding represents a single-stage third-order reaction.

Organization of designed nanofibrils assembled from alpha-helical peptides as determined by electron microscopy.

Self-assembling peptides present attractive platforms for engineering materials with controlled nanostructures. Recently, an alpha-helical fibril forming peptide (alphaFFP) was designed that self-assembles into nanofibrils at acid pH. Circular dichroism spectroscopy, electron-microscopy and x-ray fibre diffraction data showed that the most likely structure of alphaFFP fibrils is a five-stranded coiled coil rope.

Compact globular structure of Thermus thermophilus ribosomal protein S1 in solution: sedimentation and calorimetric study.

Ribosomal protein S1 of Thermus thermophilus overexpressed in Escherichia coli cells has been isolated and subjected to studies by analytical sedimentation and differential scanning microcalorimetry techniques. It has been demonstrated that the protein of 60 kDa sediments at s020,w = 4.6 S and has the diffusion coefficient D020,w = 6.