AVS 46th International Symposium
    Biomaterial Interfaces Group Wednesday Sessions
       Session BI-WeP

Paper BI-WeP15
Conformational Studies of Human Salivary Histatin-5 Bound to Hydroxyapatite Surfaces and Lipid Bilayers

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: M. Cotten, University of Washington
Authors: M. Cotten, University of Washington
J.L. Dindot, University of Washington
P.S. Stayton, University of Washington
G.P. Drobny, University of Washington
Correspondent: Click to Email
Histatin-5 (hsn5) is a human salivary polypeptide found in the acquired enamel pellicle. The protein is histidine-rich and basic (DSHAKRHHGYKRKFHEKHHSHRGY), and possesses at least two important functions: control of HAP crystal growth and antimicrobial activity. Previous studies have characterized functionally important regions of the peptide sequence as well as some secondary conformation analysis in solution. Very little is known about specific hsn5/HAP and hsn5/lipid bilayer interactions and the conformation of the HAP-bound peptide. This knowledge is nevertheless necessary to better understand molecular recognition and structure-functions relationships. Our primary goals have been to characterize the conformation of hsn5 both free and bound to HAP crystals and lipid bilayers. Moreover, we have been interested in identifying interactions between the peptide and HAP by using solid state NMR techniques. Solid state NMR experiments that measure internuclear distances to sub-Angstrom accuracy have been performed to determine distances between two 13C carbonyl labels of adjacent amino acids and thereby constrain the conformation of the peptide bound to HAP. In addition, hisn5 with a 15N amide label has been incorporated into hydrated oriented lipid bilayers and used to determine the orientation of the peptide with respect to the bilayer.