[The identification and partial characterization of merosin--a new specific protein of the basement membranes of certain tissues].
A tissue-specific basement membrane-associated protein has been identified by the use of monoclonal antibodies prepared against a protein fraction of human placenta. In frozen sections of human tissues the monoclonal antibodies decorated basement membranes of Schwann cells, striated muscle, and trophoblast. In antibody-affinity chromatography of limited pepsin digests of human placenta, a 65-kDa polypeptide was bound by the monoclonal antibodies. Polyclonal antisera and new monoclonal antibodies were raised against the isolated 65-kDa polypeptide, and they stained human tissues identically to the original monoclonal antibodies. An 80-kDa polypeptide was detected by these antibodies in placental extracts prepared without proteolysis. The 65-kDa and 80-kDa polypeptides were immunologically distinct from laminin, type IV collagen, fibronectin and major serum proteins. These polypeptides are presumably derived from a novel basement membrane-associated protein which we named merosin. Several cDNA clones were isolated which code for a protein specifically recognized by polyclonal antibodies to the 65-kDa fragment. In developing mouse tissues, merosin was first detected at the newborn stage. The restricted tissue distribution and the late development appearance of merosin suggest that the protein has a tissue-specific function in highly differentiated cells.
Leivo
I
I
Ehrig
K
K
Engvall
E
E
D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D001485:Basement Membrane / Q000737:chemistry*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007158:Immunologic Techniques; D007797:Laminin / Q000032:analysis*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification*; D051379:Mice; D008970:Molecular Weight; D009132:Muscles / Q000737:chemistry; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D012583:Schwann Cells / Q000737:chemistry; D014327:Trophoblasts / Q000737:chemistry
D000911:Antibodies, Monoclonal; D007797:Laminin; D008565:Membrane Proteins
Identifikatsiia i chastichnaia kharakteristika merosina--novogo spetsificheskogo belka bazal'nykh membran nekotorykh tkaneĭ.