Leptospira Go Formyl Enzyme X-ray Absorption Spectroscopy Study

Metalloproteins that constitute almost 40% of the proteins of the entire genome are an important class of proteins responsible of many fundamental biological processes. They exploit the redox and coordination chemistry of biological metals performing a wide variety of chemical reactions. Actually, small changes of the site of the metal ion and of its ligand atoms have a profound effect on the entire protein structure triggering different complex biological processes. X-ray absorption spectroscopy (XAS) is a valuable tool to investigate the local coordination environment of specific atoms with sub-atomic resolution. This technique can be applied to any physical state and it may be applied in biology to study metal ions in different systems. XAS is an effective probe for the local structure of active site in metalloprotein at high resolution. XAS technique used in metalloprotein is specially named BioXAS.In eubacterium as well as in mitochondria and chloroplasts the protein synthesis begins with formylmethionine- tRNA_i resulting in the synthesis of N-terminally formylated polypeptides During the elongation of the polypeptide chain the formyl group is removed hydrolytically by the Peptide deformylase (PDF, EC 3.5.1.27), which seems to be a universally conserved feature of the prokaryotic protein synthesis and an essential component for bacterial survival. The PDF is an attractive target for the design of new antibiotics since the deformyling apparently does not occur in the cytoplasm of eucaryotic cells.Leptospira interrogans PDF is an important zinc metalloprotein and plays a key role in protein synthesis of Leptospira interrogans, a ubiquitous environmental bacterium that can cause the infections of animals and humans. Previous work has shown that the activity of LiPDF is strongly affected by changes in pH values, temperature and metal ion. The enzymatic activity has being progressively decreased as the pH was reduced from 7.0 and almost constant from 7.0 up to 10.5. That is to say LiPDF with a broad optimum pH values to alkali area. Although it has long been studied on pH values to protein activity, the biochemical mechanism for pH-dependent enzymatic activity difference has never been conclusively...