Abstract
Background: CXCL4L1 is a highly potent anti-angiogenic and anti-tumor chemokine, and its structural information is unknown. Results: CXCL4L1 x-ray structure is determined, and it reveals a previously unrecognized chemokine structure adopting a novel C-terminal helix conformation. Conclusion: The alternative helix conformation enhances the anti-angiogenic activity of CXCL4L1 by reducing the glycosaminoglycan binding ability. Significance: Chemokine C-terminal helix orientation is critical in regulating their functions. Copyright © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.