One of the most common substances used for doping is EPO (erythropoietin), which is difficult to detect. In an era when there are increasing numbers of “copies” of biotechnologically produced medications (biosimilars), it is also becoming more and more difficult to detect the difference between the body’s own EPO and that made biosynthetically. Chemists at Vienna University of Technology (TU) working jointly with ARC Seibersdorf, are developing a new analytical method, based on MALDI mass spectrometry, to track down the perpetrators of doping.
“With the aid of MALDI mass spectrometry, a method that is used for non-destructive desorption/ionisation of large molecules, especially biopolymers, we compare the deceptively similar ‘humanised’ form of EPO with the body’s own substance. The two samples differ in the structure of the amino acid chains and/or in that of the associated sugar chains. Depending on the structure of these sugar chains and where they bind to, we can recognise whether this is a natural or biosynthetic EPO”, explains Professor Günter Allmaier of the Institute of Chemical Technologies and Analytics at Vienna University of Technology.
Previous methods, for example iso electric focusing, exhibit several weaknesses. First, it takes between two and three days to obtain the test results. Furthermore, the method is regarded as difficult to automate, and is based on antibodies which can detect EPO in urine but sometimes are too nonspecific and do not distinguish the structure sufficiently precisely. Allmaier and his co-workers are concentrating now on a search for suitable analytical strategies that can detect recombinant EPO directly in urine. Lab-on-chip technology is to be combined with laser-based time-of-flight mass spectrometry. Following the testing phase, Allmaier estimates that the method may reach the patentable stage around 2009 and provide a valuable support in the fight against doping. Allmaier points out that “the most essential point in our strategy is that we are developing a method with which the EPO molecule itself is detected. All the other methods used so far have been indirect.”
EPO preparations increase the production of red blood cells, which in turn transport more oxygen in the blood. As a result, the organism’s performance improves. That is why EPO has been misused for doping as far back as the late 1980s, mainly in endurance sports such as cycling. Recently, Günter Allmaier received the John Beynon Prize Award 2007 for the most innovative publication in Rapid Communications in Mass Spectrometry for the period 2005 to 2006 (http://www3.interscience.wiley.com/cgi-bin/fulltext/114298803/ PDFSTART). This work was also the starting point for intensive cooperation with Dr Reichel of ARC Seibersdorf’s doping control laboratory.