| Abstract
| - The integrin α3β1 plays important roles in development, angiogenesis, and the pathogenesis of cancer,suggesting potential therapeutic uses for antagonists of this receptor. Recently, an α3β1 integrin-bindingsite was mapped to residues 190−201 (FQGVLQNVRFVF) of the N-terminal domain of the secreted proteinthrombospondin-1 (TSP1). This sequence displays diverse biological activities in vitro and inhibitsangiogenesis in vivo. Herein we describe the NMR solution conformation of this segment in both water anddodecylphosphocholine micelles. While essentially unstructured in water, a more well-defined conformationis populated in micelles, particularly in the C-terminal half of the peptide and correlated with increasedbiological activity of the micellar peptide. The data suggested that the residues that are critical for biologicalactivity are contained in a structurally well-defined segment of the peptide. These data support the role ofthe NVR motif as a required element of full-length TSP1 for specific molecular recognition by the α3β1integrin.
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