1g91

From Proteopedia

Revision as of 09:19, 20 March 2008

SOLUTION STRUCTURE OF MYELOID PROGENITOR INHIBITORY FACTOR-1 (MPIF-1)

Overview

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.

About this Structure

1G91 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

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, J Biol Chem. 2001 Feb 16;276(7):4909-16. Epub 2000 Nov 1. PMID:11060285

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