A tale of two tails: why are terminal residues of proteins exposed?

• DOI: 10.1093/bioinformatics/btl318
• Publication Date: 2007-01-19T18:51:12Z
• Authors: Etai Jacob; Ron Unger
• Keywords: Folding (DSP implementation); Lattice protein

It is widely known that terminal residues of proteins (i.e. the N- and C-termini) are predominantly located on surface exposed to solvent. However, there no good explanation as forces driving this phenomenon. The common charged, charged prefer be surface, cannot explain magnitude Here, we survey a large number from PDB in order explore, quantitatively, phenomenon, then use lattice model study mechanisms involved.The location termini was examined for 425 small monomeric (50-200 amino acids) it found average solvent accessibility 87.1% compared with 49.2% 35.9% all residues. Using cutoff 50% maximal possible exposure, 80.3% N-terminal 86.1% C-terminal 32% In addition, much more distant center mass their than other 2D lattice, population studied three levels: structural selection compact structures, thermodynamic conformations pronounced energy gap kinetic fast folding using Monte-Carlo simulations. Progressively, each raises proportion resulting similar proportions those observed real proteins.