title: Biophysical characterization of recombinant human ameloblastin.
abstract: Ameloblastin (AMBN) is a protein expressed mainly during dental hard tissue development. Biochemically, it is classified as an intrinsically disordered protein (IDP). Its biological role remains largely unknown; however, the question of AMBN function will undoubtedly be connected to its structural properties and its potential for protein-protein and protein-cell interactions. A basic biophysical characterization of human recombinant ameloblastin (hrAMBN) and its N- and C-terminal domains by means of circular dichroism spectroscopy and dynamic light scattering showed that under physiological conditions ameloblastin is an IDP with a prevalent polyproline-II (PPII) conformation. Both the N- and C-terminal polypeptides, when expressed independently, showed different structural preferences upon heating as well as different behaviour in the presence of trifluoroethanol and CaCl(2) salt. The N-terminal peptide showed a more ordered structure with a strong tendency to adopt a helical conformation upon the addition of trifluorethanol, whereas the C-terminal domain seemed to be primarily responsible for the structural disorder of the entire AMBN molecule.
authors.affiliation: Institute of Microbiology v.v.i, Academy of Sciences of Czech Republic, Vídeňská, 1083, 142 20 Prague 4 Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Wald
authors.forename: Lucie
authors.initials: L
authors.lastname: Bednárová
authors.forename: Radim
authors.initials: R
authors.lastname: Osička
authors.forename: Petr
authors.initials: P
authors.lastname: Pachl
authors.forename: Miroslav
authors.initials: M
authors.lastname: Sulc
authors.forename: Stale Petter
authors.initials: SP
authors.lastname: Lyngstadaas
authors.forename: Ivan
authors.initials: I
authors.lastname: Slaby
authors.forename: Jiří
authors.initials: J
authors.lastname: Vondrášek
mesh_terms: D055592:Biophysical Phenomena; D002122:Calcium Chloride / Q000494:pharmacology; D002942:Circular Dichroism; D003432:Cross-Linking Reagents; D003746:Dental Enamel Proteins / Q000737:chemistry*; D006801:Humans; D009994:Osmolar Concentration; D011487:Protein Conformation / Q000187:drug effects; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D012542:Scattering, Radiation; D020539:Sequence Analysis, Protein; D012965:Sodium Chloride / Q000494:pharmacology; D013057:Spectrum Analysis; D013696:Temperature; D014270:Trifluoroethanol / Q000494:pharmacology
chemical_list: C490889:AMBN protein, human; D003432:Cross-Linking Reagents; D003746:Dental Enamel Proteins; D011994:Recombinant Proteins; D012965:Sodium Chloride; D014270:Trifluoroethanol; D002122:Calcium Chloride