Group of Chromoproteins Chemistry
We carry out high-tech MALDI-, ESI- and MS-MS- mass spectrometry for unambiguous protein identification and detection of posttranslational modifications. We also utilize molecular biology methods for protein engineering purposes and computer-assisted modeling and macromolecular X-ray crystallography as well, to determine atomic-resolution structures.
Our group carries out research that is mainly focused on studying post-translational modifications of proteins, with a particular emphasis on fluorescent proteins of the GFP-family. After polypeptide folding, the GFP-like protein undergoes maturation via consecutive post-translational autocatalytic reactions and the result of these reactions is a chromophore composed from modified amino acids. Different types of chromophore mostly account for diverse spectral properties of GFP-like proteins. Our group studies post-translational reaction mechanisms, proteins’ 3D structure and the structure of different types of chromophore, with the ultimate goal to understand how structural features affect spectral properties.
By biochemical methods and high-resolution mass-spectrometry the new post-translational modification of fluorescent protein z2FP574 from the coral polype Zoanthus sp. 2 has been discovered. It was shown that, in contrast to DsRed-like proteins, the z2FP574 chromophore undergoes coupled oxidation-decarboxylation, and this reaction is a prerequisite to green-to-red fluorescence transition of the protein. To probe the intermediate products of the reaction, a mutant has been obtained, in which oxidation-decarboxylation is controlled by temperature (look at the picture, upper inset). The obtained crystal structures of the intermediate green and final red fluorescent states of the mutant made it possible to draw the conclusions about structural basis of the green-to-red transition.