| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Pathology, School of Medicine, State University of New York, Stony Brook, NY 11794
The vitamin D binding protein (DBP) is a multifunctional plasma protein that can modulate certain immune and inflammatory responses. The diverse cellular functions of DBP appear to require cell surface binding to mediate these processes. Numerous reports have detected DBP bound to the surface of several cell types and would support the concept of a cell surface binding site for DBP. However, direct evidence for such a molecule has been lacking and essentially nothing is known about its basic biochemical properties. In the present study, radioiodinated DBP was used as a probe to characterize biochemically the neutrophil DBP binding site. Radiolabeled DBP binds to and remains associated with the plasma membrane and is not degraded. Quantitation of DBP binding to either intact cells or purified plasma membranes showed nonsaturable (linear) binding with positive cooperativity, possibly suggesting DBP oligomer formation. Solubilization of cell bound 125I-DBP with various nonionic and zwitterionic detergents demonstrated that DBP binds to a membrane macromolecule that partitions to the detergent insoluble fraction. Moreover, this molecule does not associate with the cytoskeleton. Cross-linking of radiolabeled DBP bound to plasma membranes increased the amount of protein that partitioned to the insoluble fraction, and analysis of these complexes by SDS-PAGE revealed that they may be very large since they did not enter the gel. Finally, treatment of plasma membranes with either proteases or chondroitinase ABC completely abrogated membrane binding of DBP, suggesting that the protein binds to a chondroitin sulfate proteoglycan.
This article has been cited by other articles:
|
|
 |
|
  S. R. Bates, A. S. Kazi, J.-Q. Tao, K. J. Yu, D. S. Gonder, S. I. Feinstein, and A. B. Fisher Role of P63 (CKAP4) in binding of surfactant protein-A to type II pneumocytes Am J Physiol Lung Cell Mol Physiol, October 1, 2008; 295(4): L658 - L669. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 U. Meier, O. Gressner, F. Lammert, and A. M. Gressner Gc-Globulin: Roles in Response to Injury Clin. Chem., July 1, 2006; 52(7): 1247 - 1253. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. A. McVoy and R. R. Kew CD44 and Annexin A2 Mediate the C5a Chemotactic Cofactor Function of the Vitamin D Binding Protein J. Immunol., October 1, 2005; 175(7): 4754 - 4760. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Zhang and R. R. Kew Identification of a Region in the Vitamin D-binding Protein that Mediates Its C5a Chemotactic Cofactor Function J. Biol. Chem., December 17, 2004; 279(51): 53282 - 53287. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Trujillo and R. R. Kew Platelet-Derived Thrombospondin-1 Is Necessary for the Vitamin D-Binding Protein (Gc-Globulin) to Function as a Chemotactic Cofactor for C5a J. Immunol., September 15, 2004; 173(6): 4130 - 4136. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. White, S. A. Liebhaber, and N. E. Cooke 129X1/SvJ Mouse Strain Has a Novel Defect in Inflammatory Cell Recruitment J. Immunol., January 15, 2002; 168(2): 869 - 874. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. J. DiMartino, A. B. Shah, G. Trujillo, and R. R. Kew Elastase Controls the Binding of the Vitamin D-Binding Protein (Gc-Globulin) to Neutrophils: A Potential Role in the Regulation of C5a Co-Chemotactic Activity J. Immunol., February 15, 2001; 166(4): 2688 - 2694. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
