title: A topologically related singularity suggests a maximum preferred size for protein domains.
abstract: A variety of protein physicochemical as well as topological properties, demonstrate a scaling behavior relative to chain length. Many of the scalings can be modeled as a power law which is qualitatively similar across the examples. In this article, we suggest a rational explanation to these observations on the basis of both protein connectivity and hydrophobic constraints of residues compactness relative to surface volume. Unexpectedly, in an examination of these relationships, a singularity was shown to exist near 255-270 residues length, and may be associated with an upper limit for domain size. Evaluation of related G-factor data points to a wide range of conformational plasticity near this point. In addition to its theoretical importance, we show by an application of CASP experimental and predicted structures, that the scaling is a practical filter for protein structure prediction.
authors.affiliation: Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois 60612, USA. jzbilut@rush.edu
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Zbilut
authors.forename: Gek Huey
authors.initials: GH
authors.lastname: Chua
authors.forename: Arun
authors.initials: A
authors.lastname: Krishnan
authors.forename: Cecilia
authors.initials: C
authors.lastname: Bossa
authors.forename: Kristian
authors.initials: K
authors.lastname: Rother
authors.forename: Charles L
authors.initials: CL
authors.lastname: Webber
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giuliani
mesh_terms: D001665:Binding Sites; D007700:Kinetics; D008962:Models, Theoretical; D008970:Molecular Weight; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins