Molecular markers are an important tool in biotechnology for following a biological molecule or leading another molecule to it. Most of the known markers cannot label lipids, so we wanted to discover such molecules and potentially expand the set of lipid targets. The problem with studying membrane lipids lies mainly in the lack of simple techniques such as electrophoretic separation, and in the fact that lipids do not carry biological information in the same way as e.g. DNA. By screening wild mushrooms, we first checked whether they express proteins that can bind to different membrane lipid receptors. Based on the screening analysis, we found that the aqueous extract of velvet chanterelle contains a protein with affinity for phosphatidylserine (PS). PS markers are of great biotechnological interest, as the presence of PS in the outer layer of mammalian plasma membranes is one of the key features of cancer cells and those that undergo apoptosis. To determine the amino acid sequence of a protein that has been shown to bind specifically to membrane PS, we isolated and characterized the genome of the velvet chanterelle. The genome mapping provided information on the candidate proteins encoded by the velvet chanterelle. Since the protein could be isolated by polyacrylamide gel electrophoresis, its amino acid sequence could be further characterized by mass spectrometry and Edman degradation. The latter two methods, in combination with the annotated genome, gave us a protein sequence. We envisage that this protein has great potential as a biomarker for cancer and apoptotic cells, and the presence of PS represents a target whose potential is still under-exploited in current diagnostics and therapeutics.
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