Small molecular weight proteins/peptides present in the in vivo formed human acquired enamel pellicle

Objective: The aim of this study was to investigate the type and the nature of peptides present in the in vivo formed human acquired enamel pellicle. Design: Pellicle material was collected from 10 volunteers and subjected to sample preparations consisting of centrifugal filtration using a 10 kDa molecular weight cut-off membrane and high-resolution gel filtration chromatography. The fractions containing peptides <10 kDa obtained by both methods were analyzed by LC-ESI-MS/MS. Results: 78 natural pellicle peptides with molecular weights ranging from 766.9 Da to 3981.4 Da were identified originating from 29 different proteins. Conclusions: The number of peptides present in acquired enamel pellicle appears to be large and this is likely to enhance the functional spectrum of this protein film. The presence of small peptides in pellicle may be functionally important since structure/function studies of many salivary proteins have shown that specific domains within these native proteins retain or even exhibit enhanced biological activities. The data present the basis for determining the precise function of these pellicle peptides and for gaining insights into the role pellicle plays in the oral cavity. (C) 2009 Elsevier Ltd. All rights reserved.