Characterisation of the protein composition of peripheral blood mononuclear cell microsomes by SDS-PAGE and mass spectrometry

• Published in: Journal of immunological methods 2005-10, Vol.305 (1), p.84-93
• Main Authors: Nicholson, Ian C., Mavrangelos, Chris, Fung, Kim, Ayhan, Mustafa, Levichkin, Ilya, Johnston, Amelia, Zola, Heddy, Hoogenraad, Nicholas J.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; CD molecules; Cell Membrane - chemistry; DNA, Complementary - genetics; Electrophoresis, Polyacrylamide Gel; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Leukocytes, Mononuclear - chemistry; Mass Spectrometry; Membrane Proteins - analysis; Membrane Proteins - genetics; Microsomes - chemistry; Molecular immunology; Plasma membrane proteins; Proteomics; Techniques
• ISSN: 0022-1759; 1872-7905
• DOI: 10.1016/j.jim.2005.07.005

Approximately 340 leucocyte plasma membrane proteins have been characterised by the eight Human Leucocyte Differentiation Antigen workshops held between 1982 and 2004, based primarily on their reactivity with monoclonal antibodies. The human genome is predicted to encode approximately 34,000 cDNA transcripts, of which between 15% and 20% are predicted to contain one or more transmembrane helices. We have used SDS-PAGE separation coupled with mass spectrometry-based peptide mass tag identification to identify novel plasma membrane proteins in microsome preparations prepared from mononuclear cells obtained from human peripheral blood. A total of 361 distinct proteins were identified in a single preparation, including 37 known leucocyte plasma membrane proteins, 27 potential novel plasma membrane proteins whose expression on PBMC is poorly characterised, and 51 other proteins for which the subcellular location could not be determined. Expression analysis using cDNA panels indicates that several of these novel plasma membrane proteins are differentially expressed in lymphocyte subsets. These results show that previously unidentified lymphocyte plasma membrane proteins can be identified using this approach.