Structural basis for matrix metalloproteinase 1-catalyzed collagenolysis

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Collagenolysis, the breakdown of collagen's triple-helix, is vital but poorly understood.
• Matrix metalloproteinase 1 (MMP-1) is a key enzyme involved in collagen degradation.

Purpose of the Study:

• To elucidate the mechanism and energetics of collagenolysis by MMP-1.
• To characterize the roles of MMP-1's hemopexin-like (HPX) and catalytic (CAT) domains in substrate binding and hydrolysis.

Main Methods:

• Utilized NMR spectroscopy to analyze 12 enzyme-substrate complexes of MMP-1 and collagen peptide models.
• Investigated the energetics and structural dynamics of collagenolysis.

Main Results:

• Identified a specific binding interaction between the MMP-1 HPX domain and collagen residues 782-785.
• Described a unique orientation of the triple-helix within the MMP-1 HPX and CAT domains, differing from the X-ray 'closed' conformation.
• Demonstrated a domain rotation mechanism that positions a collagen chain for hydrolysis in the CAT domain active site.

Conclusions:

• Provided a detailed, experimentally validated mechanism for collagenolysis.
• Offered significant insights into the functional roles of distinct extracellular protease domains.