Analysis of Protein–Protein Interactions and Proteomic Profiles of Normal Human Lenses

Abstract

Purpose: To investigate proteomic profiles of normal human lenses and their key proteins in protein–protein interactions (PPIs).

Materials and Methods: Water-soluble and water-insoluble proteins extracted from human lenses were first separated by one-dimensional sodium dodecyl sulfate polyacrylamide gel, and then in-gel digested with trypsin into peptides eluted by reversed-phase high-performance liquid chromatography. The eluted peptides were analyzed by linear ion trap tandem mass spectrometry (MS/MS). The raw data was filtered by TurboSEQUEST algorithm. The reverse database was used for peptide false-positive rate estimation. A network chart was constructed by the identified lens PPIs in accordance with interaction database systems.

Results: From normal human lenses 339 proteins in total were identified, including many formerly unidentified low-abundance proteins. Key proteins we recognized included plectin, actin, spectrin (α, β), vimentin, 14-3-3 protein (β/α, ζ/δ, ϵ, γ, η), TSC2, guanine nucleotide-releasing protein, laminin γ, mitogen-activated protein kinase, α-A-crystallin, heat-shock protein (α, β), glyceraldehyde 3-phosphate dehydrogenase, and collagen IV α.

Conclusions: Key proteins of normal human lenses were studied by constructing a network chart of the identified lens PPIs. The results suggest that linear ion trap MS/MS is an effective tool for detecting low-abundance proteins of human lenses. This study provides valuable data for further proteomic research of the human lens development and lens diseases.

KEYWORDS::

• Human lens
• Proteome
• Polyacrylamide gel electrophoresis
• Liquid chromatography
• Mass spectrometry
• Protein–protein interactions

ACKNOWLEDGMENT

This study was supported by a Science Technical Planning Department grant (No:1091172-1-05), Shenyang, Liaoning Province, China.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.