title: Evaluation of different methods of protein extraction and identification of differentially expressed proteins upon ethylene-induced early-ripening in banana peels.
abstract: BACKGROUND
  Banana peels (Musa spp.) are a good example of a plant tissue where protein extraction is challenging due to the abundance of interfering metabolites. Sample preparation is a critical step in proteomic research and is critical for good results.
  
  
  RESULTS
  We sought to evaluate three methods of protein extraction: trichloroacetic acid (TCA)-acetone precipitation, phenol extraction, and TCA precipitation. We found that a modified phenol extraction protocol was the most optimal method. SDS-PAGE and two-dimensional gel electrophoresis (2-DE) demonstrated good protein separation and distinct spots of high quality protein. Approximately 300 and 550 protein spots were detected on 2-DE gels at pH values of 3-10 and 4-7, respectively. Several spots were excised from the 2-DE gels and identified by mass spectrometry.
  
  
  CONCLUSIONS
  The protein spots identified were found to be involved in glycolysis, the tricarboxylic acid cycle, and the biosynthesis of ethylene. Several of the identified proteins may play important roles in banana ripening.
authors.affiliation: Key Laboratory of Tropical Crop Biotechnology, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences (CATAS), Haikou 571101, P.R. China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Zhang
authors.forename: Ren-Jun
authors.initials: RJ
authors.lastname: Feng
authors.forename: Yin-Dong
authors.initials: YD
authors.lastname: Zhang
mesh_terms: D000096:Acetone; D004586:Electrophoresis; D005030:Ethylenes / Q000096:biosynthesis*; D005638:Fruit / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D028521:Musa / Q000378:metabolism*; D010636:Phenols; D010940:Plant Proteins / Q000032:analysis* / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D014238:Trichloroacetic Acid
chemical_list: D005030:Ethylenes; D010636:Phenols; D010940:Plant Proteins; D000096:Acetone; D014238:Trichloroacetic Acid; C036216:ethylene