title: Second virial coefficient determination of a therapeutic peptide by self-interaction chromatography.
abstract: Self-interaction of macromolecules has been shown to play an important role in a number of physical processes, including crystallization, solubility, viscosity, and aggregation. Peptide self-interaction is not as well studied as for larger proteins, but should play an equally important role. The osmotic second virial coefficient, B, can be used to quantify peptide and protein self-interaction. B values are typically measured using static light scattering (SLS). Peptides, however, do not scatter enough light to allow such measurements. This study describes the first use of self-interaction chromatography (SIC) for the measurement of peptide B values because SIC does not have the molecular size limitations of SLS. In the present work, SIC was used to measure B for enfuvirtide, a 36-amino acid therapeutic peptide, as a function of salt concentration, salt type, and pH. B was found to correlate strongly with solubility and apparent molecular weight. In general, the solubility of enfuvirtide increases with pH from 6 to 10 and decreases as the salt concentration increases from 0 to 0.5M for three different salts. The effect of peptide concentration on B was also investigated and shown to have a significant effect, but only at high concentrations (>80 mg/mL).
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, CO.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Payne
authors.forename: Rajiv
authors.initials: R
authors.lastname: Nayar
authors.forename: Ralph
authors.initials: R
authors.lastname: Tarantino
authors.forename: Sam
authors.initials: S
authors.lastname: Del Terzo
authors.forename: John
authors.initials: J
authors.lastname: Moschera
authors.forename: Jie
authors.initials: J
authors.lastname: Di
authors.forename: David
authors.initials: D
authors.lastname: Heilman
authors.forename: Brian
authors.initials: B
authors.lastname: Bray
authors.forename: Mark Cornell
authors.initials: MC
authors.lastname: Manning
authors.forename: Charles S
authors.initials: CS
authors.lastname: Henry
mesh_terms: D002845:Chromatography / Q000379:methods*; D000077560:Enfuvirtide; D015700:HIV Envelope Protein gp41 / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009995:Osmosis; D010446:Peptide Fragments / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry
chemical_list: D015700:HIV Envelope Protein gp41; D010446:Peptide Fragments; D012996:Solutions; D000077560:Enfuvirtide