Non-linear hydrophobic-induced pKa shifts: Implications for efficiency of conversion to chemical energy
✍ Scribed by Dan W. Urry; D. Channe Gowda; Shao Qing Peng; Timothy M. Parker
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 589 KB
- Volume
- 239
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
By using one Asp or one Glu per thirty residues in a polytricosapeptide capable of exhibiting a hydrophobic folding and assembly transition and stepwise converting a set of the five Val residues (most proximal to the Asp or Glu residue) to more-hydrophobic Phe residues, a non-linear hydrophobic-induced pK a shift was observed with a ApK a of 0.4 (Asp) and 0.3 (Glu) on addition of 2 Phe residues per 30mer but with a ApK a of 4.7 (Asp) and 2.7 (Glu) on going from 4 Phe/30mer to 5 Phe/30mer. As a shift in pK a can be equivalent to the conversion to chemical energy from whatever energy inputmechanical, chemical, electrochemical, pressure or light -which effects a change in hydrophobicity, the non-linear hydrophobic-induced pK a shift means increased efficiency of energy conversion with increased hydrophobicity of the protein-based polymer.