Revised Manuscript Received September 23, 1993® abstract: A 67-kDa cell-surface elastin/laminin receptor is expressed by fetal bovine ligamentum nuchae fibroblasts and neutrophils. Two hexapeptides, VGVAPG and PGAIPG, contained within hydrophobic domains of tropoelastin are binding sites for this receptor. Studies of recombinant tropoelastin proteins and synthetic peptides demonstrated that a monoclonal antibody, BA4, recognized peptide sequences similar to those recognized by the 67-kDa receptor. Taking advantage of this similarity, an “epitope library” containing random hexapeptides was screened with BA4. Four BA4-selected peptides (VGAMPG, VGMAPG, VGSLPG, and VGLSPG) were synthesized; studies of fibroblast and neutrophil migration support the hypothesis that these peptides are ligands of the 67-kDa receptor present on ligamentum nuchae fibroblasts and neutrophils. Two additional, physically similar tropoelastin peptides, AGAIPG and PGAVGP, were also identified as peptide ligands, and hence potential binding sites within tropoelastin, of the elastin receptor. These data suggest that the 67-kDa elastin/laminin receptor may interactwith a wide range of structurally similar peptides containing amino acid substitutionsinvolving small nonpolar and uncharged amino acids.

Fetal bovine fibroblasts and chondrocytes, as well as circulating phagocytes, express a 67-kDa elastin receptor that is structurally identical to the 67-kDa high-affinity, metastasisassociated laminin receptor (Wrenn et al., 1988; Mecham et al., 1989a, b; Senioretal., 1989; Mecham, 1991). This protein is a peripheral membrane protein with antigenic and functional properties of a galactoside lectin (Hinek et al., 1988; Mecham et al., 1989a, b; Grosso & Scott, 1993). The interaction of elastin and tropoelastin with thisreceptor is responsible for directed cell migration to tropoelastin, proteolytic products of elastin, and synthetic tropoelastin peptides (Senior et al., 1984; Wrenn et al., 1986, 1988; Mecham et al., 1989a, b). In elastogenic cells, this receptor may play a role in directing or aiding the integration of tropoelastin into the extracellular matrix (Hinek et al., 1988).