Identification of critical residues for plasminogen binding by the alphaX I-domain of the beta2 integrin, alphaXbeta2 - PubMed (original) (raw)

. 2007 Oct 31;24(2):240-6.

Affiliations

Free article

Identification of critical residues for plasminogen binding by the alphaX I-domain of the beta2 integrin, alphaXbeta2

Jongyun Gang et al. Mol Cells. 2007.

Free article

Abstract

The beta2 integrins on leukocytes play important roles in cell adhesion, migration and phagocytosis. One of the beta2 integrins, alphaXbeta2 (CD11c/CD18), is known to bind ligands such as fibrinogen, Thy-1 and iC3b, but its function is not well characterized. To understand its biological roles, we attempted to identify novel ligands. The functional moiety of alphaXbeta2, the alphaX I-domain, was found to bind plasminogen, the zymogen of plasmin, with moderate affinity (1.92 X 10-(6) M) in the presence of Mg(2+) or Mn(2+). The betaD-alpha5 loop of the alphaX I-domain proved to be responsible for binding, and lysine residues (Lys(242), Lys(243)) in the loop were the most important for recognizing plasminogen. An excess amount of the lysine analog, 6-aminohexanoic acid, inhibited alphaX I-domain binding to plasminogen, indicating that binding is lysine-dependent. The results of this study indicate that leukocytes regulate plasminogen activation, and consequently plasmin activities, through an interaction with alphaXbeta2 integrin.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances

LinkOut - more resources