Trace element analysis of proteins directly from 2d-page: an efficient strategy for metalloproteomics

Inductively coupled plasma-mass spectrometry (ICP-MS) is a sensitive analytical method to detect the total concentrations of elements in biological samples, but it is unable to identify molecules that can bind to metals, and for this reason it is vital to combine this method's use with other biochemical techniques. Therefore, in order to identify elements complexed to specific proteins, a very relevant combination of bidimensional electrophoresis followed by ICP-MS was used. Protein spots from gels were excised and submitted directly to element detection, a method not reported before. This report focused on the use of plasma from people with laryngeal carcinoma. Most elements were below detection level, with only Cr and Pb being observed in all samples. Although the relationship between metals and laryngeal cancer was not conclusive, it is possible to affirm that the methodology utilized here is successful and has the advantage of determining to which proteins the elements bind.