1b50
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NMR STRUCTURE OF HUMAN MIP-1A D26A, 10 STRUCTURES
OverviewOverview
Human CC chemokines macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES (regulated on activation normal T cell expressed), self-associate to form high-molecular mass aggregates. To explore the, biological significance of chemokine aggregation, nonaggregating variants, were sought. The phenotypes of 105 hMIP-1alpha variants generated by, systematic mutagenesis and expression in yeast were determined., hMIP-1alpha residues Asp26 and Glu66 were critical to the self-association, process. Substitution at either residue resulted in the formation of, essentially homogenous tetramers at 0.5 mg/ml. Substitution of identical, or analogous residues in homologous positions in both hMIP-1beta and, RANTES demonstrated that they were also critical to aggregation. Our, analysis suggests that a single charged residue at either position 26 or, 66 is insufficient to support extensive aggregation and that two charged, residues must be present. Solution of the three-dimensional NMR structure, of hMIP-1alpha has enabled comparison of these residues in hMIP-1beta and, RANTES. Aggregated and disaggregated forms of hMIP-1alpha, hMIP-1beta, and, RANTES generally have equivalent G-protein-coupled receptor-mediated, biological potencies. We have therefore generated novel reagents to, evaluate the role of hMIP-1alpha, hMIP-1beta, and RANTES aggregation in, vitro and in vivo. The disaggregated chemokines retained their human, immunodeficiency virus (HIV) inhibitory activities. Surprisingly, high, concentrations of RANTES, but not disaggregated RANTES variants, enhanced, infection of cells by both M- and T-tropic HIV isolates/strains. This, observation has important implications for potential therapeutic uses of, chemokines implying that disaggregated forms may be necessary for safe, clinical investigation.
DiseaseDisease
Known disease associated with this structure: HIV infection, resistance to OMIM:[182283]
About this StructureAbout this Structure
1B50 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Identification of amino acid residues critical for aggregation of human CC chemokines macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES. Characterization of active disaggregated chemokine variants., Czaplewski LG, McKeating J, Craven CJ, Higgins LD, Appay V, Brown A, Dudgeon T, Howard LA, Meyers T, Owen J, Palan SR, Tan P, Wilson G, Woods NR, Heyworth CM, Lord BI, Brotherton D, Christison R, Craig S, Cribbes S, Edwards RM, Evans SJ, Gilbert R, Morgan P, Randle E, Schofield N, Varley PG, Fisher J, Waltho JP, Hunter MG, J Biol Chem. 1999 Jun 4;274(23):16077-84. PMID:10347159
Page seeded by OCA on Mon Nov 12 16:05:49 2007