Purification of plasma membrane proteins for the proteomic analysis of hauman msenchymal stem cells

摘要

An efficient sample preparation method was developed for the analysis of plasma membrane proteins of stem cells using ultracentrifugation and aqueous two-phase extraction. The method developed was rapid (within 4 hr) and provided a relatively high purity (26-fold of cell lysate) with a high yield (2.6%). This separation process was proven to be suitable for proteomic analysis of plasma membranes on multipotent human mesenchymal stem cells (hMSC) derived from both human umbilical cord blood (hUCB) and bone marrow. In addition, hMSCs derived from human umbilical cord blood (hUCB) and bone marrow were differentiated into adipocytes and chondrocytes. Proteins which were differentially expressed by the differentiation of hMSC from bone marrow to adipocytes were analyzed. Thirty-two protein spots were shown to have different expression levels by 2-DE analysis. Among these, eight up-regulated proteins were identified by MALDI-TOF/MS, as the following: syntaxin binding protein 3, OSBP-related protein 3, phosphodiesterase, glycophorin, immunoglobulin-|ê chain variable region, peroxisome pro-liferative activated receptor gamma (PPAR-|? ), bA528A10.3.1 (novel protein similar to K1AA01616, isoform 1), and T cell receptor V-|? 4. Four proteins: syntaxin-3, OSBP-related protein 3, PPAR-|? And glycophorin were associated with adipogenesis.