Reduction-driven polypeptide folding by the delta Tt mechanism.
Poly(Gly-Val-Gly-Val-Pro), i.e., poly(GVGVP), exhibits composition and solute dependence of Tt, the temperature of the inverse temperature transition at which hydrophobic folding and assembly occur on raising the temperature. Importantly, a means whereby the value of Tt is lowered from above to below the working temperature becomes an isothermal means of driving folding and assembly, i.e., of achieving free energy transduction. Using poly[0.73(GVGVP),0.27(GK[NMeN]GVP)] where [NMeN] indicates N-methyl nicotinamide attached to the epsilon-NH2 of the Lys(K) residue, chemical and electrochemical reductions are found to remarkably lower the value of Tt; reduction can drive hydrophobic folding and assembly as effectively as decreasing ionization. Changing the redox state of a protein becomes yet another means of achieving free energy transduction by the delta Tt mechanism.
Urry
D W
DW
University of Alabama, Laboratory of Molecular Biophysics, Birmingham 35294-0019.
Hayes
L C
LC
Gowda
D C
DC
Harris
C M
CM
Harris
R D
RD
D000595:Amino Acid Sequence; D004563:Electrochemistry; D007202:Indicators and Reagents; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D017510:Protein Folding; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
D007202:Indicators and Reagents; D010455:Peptides