Polyproline Helices in Protein Structures: A Statistical Survey
Abstract:A statistical survey of polyproline II (PPII) helices extracted from protein crystal structures is here reported. The average hydrophobicity of these helices is intermediate between those displayed by β-strands and coil regions and is similar to that of α-helices. PPII helices with amphipathic properties have been identified and classified. Amino acid propensities for PPII helices derived in this study differ significantly from those previously reported. They show a little albeit significant correlation with propensities for α-helices whereas they are fully non-correlated to propensities for β-sheets. Finally, PPII propensities have been correlated with amino acid frequencies in structural proteins, such as collagen and extensins.
Document Type: Research Article
Affiliations: Istituto di Biostrutture e Bioimmagini, CNR, Via Mezzocannone 16. I-80134 Napoli, Italy and dCentro Interuniversitario di Ricerca sui Peptidi Bioattivi (C.I.R.P.E.B.), Via Mezzocannone 16. I-80134 Napoli, Italy.
Publication date: 2006-08-01
- Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.