Integrin alphaL, beta2, Recombinant, Human (LFA-1, CD11a/CD18)
Description
Purity ~95%, as determined by SDS-PAGE and visualized by silver stain. Endotoxin: ≤1EU/ug (LAL). Integrin alphaLbeta2 is one of three beta2 integrin adhesion proteins. The non-covalent heterodimer of 180kD aL/CD11a and 95kD b2/CD18 integrin subunits is expressed on virtually all leukocytes. The ligand binding site of LFA-1 is in the N-terminal head region, formed by an interaction of the vWFA (I, I-like) domains from each subunit, and the aL betapropeller structure. The aL subunit contains domains termed thigh, calf-1 and calf-2, while the b2 subunit contains a PSI region and four cysteine-rich I-EGF folds. Each subunit has a transmembrane sequence and a short cytoplasmic tail connected to the cytoskeleton. Upon activation by ``inside-out'' signaling, clustering, or Mg2+ or Mn2+ binding to metal ion-dependent adhesion sites within the vWFA domains, the molecule unfolds from its inactive, ``closed'' conformation to expose ligand binding sites. Active aLb2 binds ICAM-1/CD54, ICAM-2, ICAM-3