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Solution Structure and Dynamics of Human MMP‐12 (Metalloelastase) in its Inhibitor‐Free State
Author(s) -
Van Doren Steven R.,
Liang Xiangyang,
Bhaskaran R.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb51-c
Subject(s) - autolysis (biology) , chemistry , active site , matrix metalloproteinase , biophysics , crystallography , stereochemistry , biochemistry , enzyme , biology
To gain insights on the specificity of matrix metalloproteinase‐12 (MMP‐12) in emphysema and arterial diseases, we have been pursuing the structure and dynamics of human MMP‐12 in its inhibitor‐free state. This has been severely complicated by its inherent self‐proteolysis within a few hours. To overcome this autolysis, we extended sample lifetimes to at least 5 days (and sometimes > 1 month) and exploited a cryogenic probe. The solution structure of inhibitor‐free MMP‐12 was calculated using 1300 interresidue NOEs. A comparison of the preliminary NMR structure of the inhibitor‐free state crystallographic results on MMP‐12‐inhibitor complexes is presented. 12% of MMP‐12 residues are glycines, but their correlation with sites of observed dynamics is weak. Lower 15 N{ 1 H}NOE suggests psec‐nsec flexibility of two loops atop the β‐sheet and of three residues at the active site. Msec‐scale motion of three residues around the active site is revealed by relaxation‐compensated R2 (CPMG) relaxation. Chemical exchange in msec is also present at a calcium binding site and near one ligand to the structural zinc. Supported by American Heart Association grants 0256134Z and 0455885Z and NIH grant R01GM57289.