Relation of amino acid composition and the moffitt parameters to the secondary structure of proteins

✍ Scribed by D. E. Goldsack

• Publisher: Wiley (John Wiley & Sons)
• Year: 1969
• Tongue: English
• Weight: 721 KB
• Volume: 7
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1969.360070303

✦ Synopsis

A statistical analysis c the relation between the amino acid composition of proteins and the amount of helical secondary structure as characterized by the Moffitt bo parameter has shown a high degree of correlation of the bo parameter with those amino acids whose homopolymers can form helical structures. Using the data for 107 proteins, a linear relation was found between bo and the sum of the residue percentages of alanine, arginine, aspartic acid, cysteine, glutamic acid, leucine, andlysine. A statistical analysis of the Moffitt a. parameter, on the other hand, showed no statistically significant grouping of amino acids in relation to the amount of secondary @ structure in a protein.

A plot of bo versus a. -a:, where a? represents the a0 parameter for a fully denatured protein, for 55 proteins showed distinct nonlinearity. This nonlinearity was postulated to be due to presence of @ structure, and a nomagram was constructed which allowed a semiquantitative estimate of the amount of helical and @-type secondary structures from the 60 Venus a0a? plot.