Analysis of protein-protein interactions and proteomic profiles of normal human lenses.
OBJECTIVE
To investigate proteomic profiles of normal human lenses and their key proteins in protein-protein interactions (PPIs).


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 (alpha, beta), vimentin, 14-3-3 protein (beta/alpha, zeta/delta, epsilon, gamma, eta), TSC2, guanine nucleotide-releasing protein, laminin gamma, mitogen-activated protein kinase, alpha-A-crystallin, heat-shock protein (alpha, beta), glyceraldehyde 3-phosphate dehydrogenase, and collagen IV alpha.


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.
Yao
Zhibin
Z
Department of Ophthalmology, Fourth Affiliated Hospital, China Medical University, Shenyang, China.
Yu
Hong
H
Xuan
Dwight
D
Sha
Qian
Q
Hu
Jianwen
J
Zhang
Jinsong
J
D000328:Adult; D000465:Algorithms; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000032:analysis*; D006801:Humans; D007908:Lens, Crystalline / Q000737:chemistry*; D008297:Male; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D040901:Proteomics; D053719:Tandem Mass Spectrometry
D005136:Eye Proteins