REGULATION OF ZN-ALPHA-2-GLYCOPROTEIN-MEDIATED CELL-ADHESION BY KININOGENS AND THEIR DERIVATIVES

MC3T3-E1 (mouse osteoblast-like) cells adhered to a tissue culture pla te coated with human Zn-alpha 2-glycoprotein (Zn alpha 2gp). The adhes ion of MC3T3-E1 cells to Zn alpha 2gp was inhibited by synthetic pepti des such as RGDS and ELRGDV, and by antibody against vitronectin recep tor. These findings suggested that the RGD region of Zn alpha 2gp inte racts with the vitronectin receptor (alpha v beta 3) on the MC3T3-E1 c ell surface, Furthermore, we found that the common heavy chain of both HMW- and LMW-kininogens accelerated the Zn alpha 2gp-mediated MC3T3-E 1 cell adhesion. Among the three domains of the common heavy chain of both kininogens, domain 3 promoted the cell adhesion by up to 200%. Am ong the nine synthetic peptides covering domain 3, the peptide, N(334) AEVYVVPWEKKIYPTVN(351) accelerated in a dose-dependent manner the Zn a lpha 2gp- and vitronectin (VN)mediated MC3T3-E1 cell adhesion. These f indings suggested that a defined region of domain 3 is responsible for the acceleration of cell adhesion. (C) 1998 Academic Press.