Two Hypothetical Proteins of Human Aortic Adventitia, with Ig Kappa, Collagenous, and Aromatic-Rich Motifs

Abstract Two of five clones, selected from an expression library of aortic adventitia, encode unique hypothetical proteins sharing sequences of Ig kappa, gly/pro rich (collagenous) motifs, and aromatic motifs that occur in several proteins of the extracellular matrix. Both proteins have a similar domain structure with at least 8 regions: (1) Ig kappa (84-120 residues in length); (2) ser/thr-rich motif (44-63); (3) a second Ig kappa motif (9-12); (4) either a possible calcium-binding motif or a gly/pro rich sequence (35-43); (5) an aromatic rich sequence (6-7); (6) another gly/pro rich sequence (62-72); (7) a third Ig kappa sequence (26-28); and (8) a C-terminal 68-70 residue sequence with another aromatic motif.