title: Solution and solid-state circular dichroism analyses of a human salivary proline-rich glycoprotein repeating domain and its subfragments.
abstract: Solution- and solid-state c.d. spectra, as well as surface energetics values, were collected for a series of peptides derived from human salivary proline-rich glycoprotein (PRG). The acronyms and sequences for these peptides are as follows: PRG9-2 = NH2-G(1)-P(2)-CONH2, PRG9-3 = NH2-G(1)-P(2)-P(3)-CONH2, PRG9-4 = NH2-G(1)-P(2)-P(3)-P(4)-CONH2, PRG9-5 = NH2-G(1)-P(2)-P(3)-P(4)-H(5)-CONH2, PRG9-6 = NH2-G(1)-P(2)-P(3)-P(4)-H(5)-P(6)-CONH2, PRG9-7 = NH2-G(1)-P(2)-P(3)-P(4)-H(5)-P(6)-G(7)-CONH2, PRG9-8 = NH2-G(1)-P(2)-P(3)-P(4)-H(5)-P(6)-G(7)-K(8)-CONH2, and PRG9-9 = NH2-G(1)-P(2)-P(3)-P(4)-H(5)-P(6)-G(7)-K(8)-P(9)-CONH2. The presence of stable poly-L-proline II-like 'mini' helices in the solution state was found to be dependent on peptide chain length, pH, salt, and organic solvent type. Other conformational features such as kinks and beta-/gamma-turns were also found in the larger peptides. Solid-state peptide conformations were not necessarily related to their solution-state counterparts. Poly-L-proline II-like 'mini' helices, kinks, and beta-/gamma-turns were similarly found in the various substrate-bound PRG9 peptides. Surface energetics parameters suggested specific orientations for PRG9 peptides and their constituent acids and homopolymers.
authors.affiliation: School of Dental Medicine, State University of New York, Department of Oral Biology, Buffalo 14214.
authors.forename: M
authors.initials: M
authors.lastname: Gonzalez
authors.forename: P M
authors.initials: PM
authors.lastname: Loomis
authors.forename: R E
authors.initials: RE
authors.lastname: Loomis
mesh_terms: D002942:Circular Dichroism; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D010446:Peptide Fragments / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011392:Proline / Q000737:chemistry*; D055232:Proline-Rich Protein Domains; D011487:Protein Conformation; D012471:Salivary Proteins and Peptides / Q000737:chemistry*; D012996:Solutions; D012997:Solvents
chemical_list: D006023:Glycoproteins; D010446:Peptide Fragments; D010455:Peptides; D012471:Salivary Proteins and Peptides; D012996:Solutions; D012997:Solvents; D011392:Proline