Abstract
Collagenolysis is essential in extracellular matrix homeostasis, but its structural basis has long been shrouded in mystery. We have developed a novel docking strategy guided by paramagnetic NMR that positions a triple-helical collagen V mimic (synthesized with nitroxide spin labels) in the active site of the catalytic domain of matrix metalloproteinase-12 (MMP-12 or macrophage metalloelastase) primed for catalysis. The collagenolytically productive complex forms by utilizing seven distinct subsites that traverse the entire length of the active site. These subsites bury ∼1,080 Å(2)of surface area, over half of which is contributed by the trailing strand of the synthetic collagen V mimic, which also appears to ligate the catalytic zinc through the glycine carbonyl oxygen of its scissile G∼VV triplet. Notably, the middle strand also occupies the full length of the active site where it contributes extensive interfacial contacts with five subsites. This work identifies, for the first time, the productive and specific interactions of a collagen triple helix with an MMP catalytic site. The results uniquely demonstrate that the active site of the MMPs is wide enough to accommodate two strands from collagen triple helices. Paramagnetic relaxation enhancements also reveal an extensive array of encounter complexes that form over a large part of the catalytic domain. These transient complexes could possibly facilitate the formation of collagenolytically active complexes via directional Brownian tumbling.
Highlights
Collagenolysis is essential in extracellular matrix homeostasis, but its structural basis has long been shrouded in mystery
We have developed a novel docking strategy guided by paramagnetic NMR that positions a triple-helical collagen V mimic in the active site of the catalytic domain of matrix metalloproteinase-12 (MMP-12 or macrophage metalloelastase) primed for catalysis
To determine whether primary structure alone accounted for the observed Matrix metalloproteinases (MMPs)-12 cat activity, a single-stranded peptide analog encompassing the sequence of residues 436 – 450 of type V collagen (Gly-Pro-Pro-GlyϳVal-Val-Gly-Glu-Gln-Gly-GluGln-Gly-Pro-Pro-NH2) was utilized [27]
Summary
Collagenolysis is essential in extracellular matrix homeostasis, but its structural basis has long been shrouded in mystery. The collagenolytically productive complex forms by utilizing seven distinct subsites that traverse the entire length of the active site These subsites bury ϳ1,080 Å2 of surface area, over half of which is contributed by the trailing strand of the synthetic collagen V mimic, which appears to ligate the catalytic zinc through the glycine carbonyl oxygen of its scissile GϳVV triplet. The archetypal collagenase MMP-1 may unwind the collagen triple helix [13] or rather destabilize the helical state and stabilize the locally unwound state [19] This may occur more readily in Hyp-poor regions that are less stable and more susceptible to localized unwinding [1, 14, 20]. The classic collagenases MMP-1, -8, and -13 are joined by MMP-2 and -9 and membrane type MT1MMP and MT2-MMP [21]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
