Component of the elastin-associated microfibrils. Forms a ternary complex with BGN and ELN. Interacts with FBN1 (via N-terminal domain) and FBN2. Forms intermolecular disulfide bonds either with other MAGP-1 molecules or with other components of the microfibrils. May form transglutaminase cross-links. O-glycosylated. Belongs to the MFAP family.