A New Hydrophobicity Scale and Its Relevance to Protein Folding and Interactions at Interfaces

A hydrophobicity scale, based on the temperature, Tt, at which an inverse temperature transition of hydrophobic folding and assembly occurs in a model protein, has been used for hydrophobicity plots of protein primary structures of fibronectin, fibrinogen and two apolipoproteins. The periodicity of recurrence of hydrophobic residues could be used to identify amphiphilic β-sheets and α-helices. Evaluation of relative stability of hydrophobic domains can use the calculated hydrophobicity of the domain, i.e., Σd Tt/N = d. Domains with the lowest values of d would be the most stable and those with values closer to 37°C would be the least stable corresponding respectively to the rigid and soft nomenclature of Norde for protein adsorption at interfaces. Non-uniformity within a given hydrophobic domain can be analyzed to assess a path of hydrophobic unfolding in the process of binding at a hydrophobic interface. ISBN13: 9780841233041 eISBN: 9780841215276 http://pubs.acs.org/doi/abs/10.1021/bk-1995-0602.ch007