Proteomic analysis of protein deposits on worn daily wear silicone hydrogel contact lenses

Abstract

Purpose: Previous studies have demonstrated deposition of tear proteins onto worn contact lenses. In this study, we used proteomic techniques to analyze the protein deposits extracted from worn daily wear silicone hydrogel contact lenses in combination with different lens care solutions.

Methods: Worn lenses were collected and protein deposits extracted using urea and surfactant. Protein extracts were desalted, concentrated, and then separated using one-dimensional gel electrophoresis. Individual protein components in extracts were identified using liquid chromatography combined with tandem mass spectrometry (LC-MS-MS) after trypsin digestion.

Results: One-dimensional gel electrophoresis revealed that lysozyme and other small proteins (around 20 kDa) were the most abundant proteins in the extracts. LC-MS-MS revealed a wide array of proteins in lens extracts with lysozyme and lipocalin 1 being the most commonly identified in deposit extracts.

Conclusions: Worn contact lenses deposit a wide array of proteins from tear film and other sources. Protein deposit profiles varied and were specific for each contact lens material.

Figure 1

Examples of SDS gel analysis of the protein extracts. Lane 1 shows the balafilcon A lens with Opti-Free extract. Lane 2 shows the lotrafilcon B lens with ClearCare extract, and lane 3 shows the senofilcon A lens with ClearCare extract. Lane 4 shows galyfilcon A lens with Opti-Free extract. Band A is the tear lysozyme, and Band B shows unidentified proteins.