Automated design of the surface positions of protein helices

• Published in: Protein science 1997-06, Vol.6 (6), p.1333-1337
• Main Authors: Dahiyat, Bassil I., Benjamin Gordon, D., Mayo, Stephen L.
• Format: Article
• Language: English
• Subjects: Algorithms; Circular Dichroism; coiled coils; Computer Simulation; DNA-Binding Proteins; Fungal Proteins - chemistry; helix propensities; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Models, Chemical; Models, Molecular; Peptides - chemistry; protein design; Protein Engineering - methods; Protein Kinases - chemistry; Protein Structure, Secondary; Saccharomyces cerevisiae Proteins; Surface Properties; surface residues
• ISSN: 0961-8368; 1469-896X
• DOI: 10.1002/pro.5560060622

Using a protein design algorithm that quantitatively considers side‐chain interactions, the design of surface residues of α helices was examined. Three scoring functions were tested: a hydrogen‐bond potential, a hydrogen‐bond potential in conjunction with a penalty for uncompensated burial of polar hydrogens, and a hydrogen‐bond potential in combination with helix propensity. The solvent exposed residues of a homodimeric coiled coil based on GCN4‐p1 were designed by using the Dead‐End Elimination Theorem to find the optimal amino acid sequence for each scoring function. The corresponding peptides were synthesized and characterized by circular dichroism spectroscopy and size exclusion chromatography. The designed peptides were dimeric and nearly 100% helical at 1°C, with melting temperatures from 69‐72°C, over 12°C higher than GCN4‐p1, whereas a random hydrophilic sequence at the surface positions produced a peptide that melted at 15°C. Analysis of the designed sequences suggests that helix propensity is the key factor in sequence design for surface helical positions.