Solution structure and dynamics of myeloid progenitor inhibitory factor-1 (MPIF-1), a novel monomeric CC chemokine.Rajarathnam, K., Li, Y., Rohrer, T., Gentz, R.
(2001) J.Biol.Chem. 276: 4909-4916
- PubMed: 11060285
- DOI: 10.1074/jbc.M005085200
- PubMed Abstract:
MPIF-1, a CC chemokine, is a specific inhibitor of myeloid progenitor cells and is the most potent activator of monocytes. The solution structure of myeloid progenitor inhibitor factor-1 (MPIF-1) has been determined by NMR spectroscopy. The structure ...
MPIF-1, a CC chemokine, is a specific inhibitor of myeloid progenitor cells and is the most potent activator of monocytes. The solution structure of myeloid progenitor inhibitor factor-1 (MPIF-1) has been determined by NMR spectroscopy. The structure reveals that MPIF-1 is a monomer with a well defined core except for termini residues and adopts the chemokine fold of three beta-strands and an overlying alpha-helix. In addition to the four cysteines that characterize most chemokines, MPIF-1 has two additional cysteines that form a disulfide bond. The backbone dynamics indicate that the disulfide bonds and the adjacent residues that include the functionally important N-terminal and N-terminal loop residues show significant dynamics. MPIF-1 is a highly basic protein (pI >9), and the structure reveals distinct positively charged pockets that could be correlated to proteoglycan binding. MPIF-1 is processed from a longer proprotein at the N terminus and the latter is also functional though with reduced potency, and both proteins exist as monomers under a variety of solution conditions. MPIF-1 is therefore unique because longer proproteins of all other chemokines oligomerize in solution. The MPIF-1 structure should serve as a template for future functional studies that could lead to therapeutics for preventing chemotherapy-associated myelotoxicity.
Department of Human Biological Chemistry and Genetics and Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, TX 77555, USA. email@example.com