Homochiral stereochemistry: the missing link of structure to energetics in protein folding.
The notion is tested that homochiral stereochemistry being ubiquitous to protein structure could be critical to protein folding as well, causing it to become frustrated energetically providing the basis for its solvent- and sequence-mediated control. The proof in support of the notion is found in a consensus of experiment and computation according to which suitable oligopeptides are in their folding-unfolding equilibria, at both macrostate and microstate levels, susceptible to dielectric because of the conflict of peptide-chain electrostatics with interpeptide hydrogen bonds when the structure is poly-L but not when it is alternating-L,D. The argument is thus made that homochiral stereochemistry may in protein folding provide the unifying basis for its solvent- and sequence-mediated control based on screening of peptide-chain electrostatics under conflict with folding of the chain due to homochiral stereochemistry. Dielectric is brought into spotlight as the effect comparatively obscure but presumably critical to the folding in protein structure for its control.
Kumar
Anil
A
Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India.
Ramakrishnan
Vibin
V
Ranbhor
Ranjit
R
Patel
Kirti
K
Durani
Susheel
S
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D055672:Static Electricity; D013237:Stereoisomerism; D013816:Thermodynamics
D010455:Peptides