ADAMTS Proteins: Concepts, Challenges, and Prospects.

The ADAMTS superfamily comprises secreted metalloproteases (ADAMTS proteases) as well as structurally related secreted glycoproteins that lack catalytic activity (ADAMTS-like proteins). Members of both families participate in diverse morphogenetic processes during embryonic development, and connective tissue maintenance and hemostasis in the adult. Several ADAMTS proteins are heavily implicated in genetic and acquired human and animal disorders. Despite these indicators of a profound biological and medical importance, detailed knowledge about their molecular structures, substrates, biological pathways, and biochemical mechanisms is significantly limited by unique intrinsic characteristics, which have led to several technical challenges. As a group, they are larger, more heavily modified, and harder to purify than other secreted proteases. In addition, idiosyncratic aspects of individual members are deserving of further investigation but can complicate their analysis. Here, some of the key concepts, challenges, and prospects in ADAMTS research are discussed in the context of the knowledge accumulated over the past two decades. Individual chapters in this volume of Methods in Molecular Biology provide practical solutions for surmounting these challenges. Since the biology of a protease is actually the biology of its substrates, there is considerable emphasis on purification of recombinant ADAMTS proteins, identification of their substrates and assays for their proteolytic activity.

Challenges and Solutions for Purification of ADAMTS Proteases: An Overview.

ADAMTS are secreted metalloproteinases implicated in many key biological processes. The 19 different members of this family share an identical domain composition at the level of their amino-terminal portion, whereas the identity and number of the domains forming their carboxy-terminal half are divergent and define distinct ADAMTS subfamilies. Due to their large size, extensive glycosylation, the presence of specific domains, their tendency to form aggregates, their relatively low abundance in tissues and the presence of many disulfide bonds, ADAMTS are very hard to isolate, express, and purify, as either native or recombinant active enzymes. This chapter provides an overview of critical steps to take into account when obtaining these proteases for biochemical and functional investigation.

Purification of Native or Recombinant ADAMTS2, and Procollagen I Cleavage Assay.

ADAMTS constitute a family of 19 secreted metalloproteinases involved in diverse physiopathological conditions. Most of their roles first emerged from analysis of spontaneous human and animal mutations or genetically engineered animals. However, the involved mechanisms and the full repertoire of their functions are still largely unrecognized, in part because they are difficult to produce and purify as recombinant active enzymes. Here we describe protocols, tips, and tricks specifically regarding ADAMTS2, 3, and 14 but still relevant for other ADAMTS.

Purification of Recombinant ADAMTSL2.

Recombinantly produced proteins are used in many biological disciplines. However, their purity and quality are vital for downstream applications used to determine their structure and functions. Several purification and detection strategies can be used in combination to obtain protein samples with homogeneity and structural conformity. Here we detail the protocols involved in the purification of ADAMTSL2 from mammalian cells. We also describe the protocols used to validate the purity of the protein samples.