Identification of foetal brain proteins by two-dimensional gel electrophoresis and mass spectrometry - Comparison of samples from individuals with orwithout chromosome 21 trisomy

Protein expression in foetal brain with or without chromosome 21 trisomy (D own's syndrome) was analyzed by two-dimensional gel electrophoresis and mas s spectrometry. Data generated by in-gel digestion and matrix-assisted lase r desorption/ionization mass spectrometry allowed identification of 40 prot eins. Most of these are common to syndrome and healthy subjects and represe nt different types of protein. However, a few proteins, identified as trunc ated structural proteins (tubulin, actin), were present in part of the tris omy samples but absent from the controls. This is interpreted to indicate i ncreased proteolysis in the syndrome samples but could also reflect some al tered expression or processing. Independent of the apparently increased pro teolysis in the syndrome samples, and in spite of the use of total brain ti ssues, the results show that two-dimensional protein separation patterns ar e largely similar between the syndrome and control samples upon silver-stai ning, but that differences associated with structural components can be det ected and identified.