[Frontiers in Bioscience E3, 250-255, January 1, 2011]

Shotgun proteomics analysis on maize chloroplast thylakoid membrane

Xiao-Yu Liu1, Ya-Dan Wu1, Zhi-Ying Shen2, Zhuo Shen1, Hua-Hua Li1, Xiao-Mei Yu3, Xiu-Feng Yan1, Chang-Hong Guo4, Bai-Chen Wang1

1Key Laboratory of Forest Tree Genetic Improvement and Biotechnology, Ministry of Education, Northeast Forestry University, 26 Hexing road, Harbin, 150040, China, 2Department of Pharmacy, Daqing Branch, Harbin Medical University, Daqing 163319, China, 3Library of Northeast Forestry University, 26 Hexing road, Harbin, 150040, China, 4Laboratory of Genetics, Faculty of Biology, Harbin Normal University, 50 Hexing road, Harbin, 150080, China


1. Abstract
2. Introduction
3. Materials and methods
3.1. Plant material and isolation of thylakoid membrane
3.2. Thylakoid membrane protein extraction and digestion
3.3. Protein digestion
3.4. Analysis by nano-UPLC-MSE tandem MS
3.5. Data processing and protein identification
3.6. Quantitative analysis
4. Results and discussion 4.1. Proteins identified on maize chloroplast thylakoid membranes
4.2. Proteins involved in chlorophyll synthesis
4.3. Proteins involved in the light-reaction of photosynthesis
4.4. Proteins involved in carbon assimilation and other functions
5. Perspective
6. Acknowledgments
7. References


In this study we initiated a proteomic investigation of the maize thylakoid membrane by using a shotgun proteomic approach based on LC-MSE. A total of 34 maize thylakoid membrane proteins were identified, the majority of which are primarily involved in photosynthesis, including the light-reaction and carbon assimilation. It is noteworthy that all of the core subunits of the Photosystem II were identified in our search. Proteins involved in other processes, such as iron storage, were also detected in our study. The quantity of each identified protein was also determined. Of interest, we discovered that the amount of the three ATP synthase subunits were not equivalent, suggesting that these proteins perform other functions in addition to ATP synthesis. To our knowledge this is the first extensive proteomic investigation of the maize thylakoid membrane, and will likely enable further study of maize photosynthesis and chloroplast development.