Total chemical synthesis and chemotactic activity of human S100A12 (EN-RAGE)

Human S100A12 (extracellular newly identified RAGE (receptor for advanced g lycosylation end products)binding protein), a new member of the S100 family of EF-hand calcium-binding proteins, was chemically synthesised using high ly optimised 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluoro phosphate/tert-butoxycarbonyl in situ neutralisation solid-phase chemistry. Circular dichroism studies indicated that CaCl2 decreased the helical cont ent by 27% whereas helicity was marginally increased by ZnCl2. The propensi ty of S100A12 to dimerise was examined by electrospray ionisation time-of-f light mass spectrometry which clearly demonstrated the prevalence of the no n-covalent homodimer (20 890 Da). Importantly, synthetic human S100A12 in t he nanomolar range was chemotactic for neutrophils and macrophages in vitro . (C) 2001 Federation of European Biochemical Societies. Published by Elsev ier Science B.V. All rights reserved.