Specific Binding of -Macroglobulin to Complement-Type Repeat CR4 of the Low-Density Lipoprotein Receptor-Related Protein
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- 作者：Olav M. Andersen ; Peter A. Christensen ; Lisa L. Christensen ; Christian Jacobsen ; S
- 刊名：Biochemistry
- 出版年：2000
- 出版时间：September 5, 2000
- 年：2000
- 卷：39
- 期：35
- 页码：10627 - 10633
- 全文大小：178K
- 年卷期：v.39,no.35(September 5, 2000)
- ISSN：1520-4995
文摘
The low-density lipoprotein receptor-related protein (LRP) is a large surface receptor thatmediates binding and internalization of a large number of structurally and functionally unrelated ligands.The ligand binding sites are located in clusters of complement-type repeats (CR), where the general absenceof mutual binding competition suggests that different ligands map to distinct sites. Binding of
mages/gifchars/alpha.gif" BORDER=0>2-macroglobulin-protease complexes to the LRP is mediated by the receptor binding domain (RBD) ofmages/gifchars/alpha.gif" BORDER=0>2-macroglobulin (mages/gifchars/alpha.gif" BORDER=0>2M). To determine the major binding epitope(s) in the LRP, we generated a completeset of tandem CR proteins spanning the second cluster of CR domains, and identified a binding site formages/gifchars/alpha.gif" BORDER=0>2M in the N-terminal part of the cluster comprising CR3-CR6, using ligand blotting and surface plasmonresonance (SPR) analysis. The specific site involved in mages/gifchars/alpha.gif" BORDER=0>2M recognition resides in the fourth CR domain,CR4, whereas another site is identified in CR5. An acidic epitope in CR4 is identified as important forbinding mages/gifchars/alpha.gif" BORDER=0>2M by mutagenesis and SPR analysis. The formation of the complex between the ratmages/gifchars/alpha.gif" BORDER=0>1-macroglobulin RBD and CR domain pairs is characterized by analytical size-exclusion chromatography,which demonstrates a sufficiently strong interaction between the mages/gifchars/alpha.gif" BORDER=0>1M RBD and CR34 or CR45 for theisolation of a complex.