52 - Microfibril-associated glycoprotein-2 MAGP2, MP25

Abstract

This chapter focuses on the structure and functions of microfibril-associated glycoprotein-2 (MAGP2), which is a glycoprotein component of 12 nm microfibrils found in a variety of elastic and nonelastic tissues. MAGP2 is shown to localize on the beaded microfibrils that contain fibrillin as a major component, although it has a more restricted distribution than MAGP1. Glycoproteins from elastin-associated microfibrils are solubilized from fetal bovine nuchal ligament, through their treatment with reductive saline extracts. MAGP2 was originally prepared from reductive guanidinium chloride extracts. It is a hydrophilic protein that contains two distinct regions—a basic cysteine-rich carboxy-terminal half and an acidic cysteine-free amino-terminal half. Overall, MAGP2 has an isoelectric point of 6.6. The chapter discusses the gene structure and isolation of MAGP2.