Clearly the functions and structure of the myometrium and placenta are different, however should investigate the expression of aB-crystallin within the placenta during labor. Also that particular study highlights how different changes in HSP 27 can occur depending on the cellular event to be targeted. In summary HSP 27 is expressed in a spatial manner in the human placenta and changes in expression occur during labor suggest that HSP 27 may be part of the signaling process of labor and thus warrants further investigation particularly with regard to a role on pre-term labor. The monomeric form of this protein has been studied extensively in aqueous solution by a wide range of biophysical methods revealing a compact intrinsically disordered state without persistent secondary or tertiary structure. Measurements of the hydrodynamic radius of this species have revealed that the structural ensemble is more compact than that expected for a random coil state, and NMR measurements of residual dipolar couplings and paramagnetic relaxation enhancements have identified weak interactions between the negatively charged C-terminal region and the positively charged N-terminal region. It has also been observed, however, that in the presence of curved, anionic lipid surfaces the N-terminal region adopts essentially complete a-helical structure. Although NMR spectroscopy is routinely applied to the study of structure and dynamics of proteins in vitro, recently the feasibility of performing high-resolution spectroscopic studies of proteins directly within living cells has been demonstrated an approach termed ‘in-cell NMR’. One of the first systems to be observed was aSyn, and both the in-cell HSQC and the directlydetected CON spectra of aSyn expressed within bacterial cells have been reported to be similar to that of the isolated protein. These observations indicated that aSyn remains intrinsically disordered within the cytosolic environment, and subsequent 19F NMR measurements of 3-fluorotyrosine chemical shifts also showed similar chemical shifts for intracellular aSyn when compared with the isolated protein. The effect of N-terminal acetylation, a post-translational modification constitutively observed for aSyn in vivo, has also been investigated by in-cell NMR for aSyn co-expressed with the N-acetyltransferase NatB within E. coli cells. While small chemical shift changes were observed in the isolated protein following N-terminal acetylation, consistent with the increase in the a-helical population in the first 12 Nterminal residues reported from in vitro studies no additional changes were observed in the HSQC spectrum of the intracellular species. In the present work, we have brought together advances in the in-cell measurements of chemical shifts with progress in the analysis of secondary structure populations in disordered proteins, to assess directly the conformation of aSyn within living cells.