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Title: Molecular Structures and Dynamics of the Stepwise Activation Mechanism of a Matrix Metalloproteinase Zymogen: Challenging the Cysteine Switch Dogma

Journal Article · · Journal of the American Chemical Society
DOI:https://doi.org/10.1021/ja073941l· OSTI ID:959763

Activation of matrix metalloproteinase zymogen (pro-MMP) is a vital homeostatic process, yet its molecular basis remains unresolved. Using stopped-flow X-ray spectroscopy of the active site zinc ion, we determined the temporal sequence of pro-MMP-9 activation catalyzed by tissue kallikrein protease in milliseconds to several minutes. The identity of three intermediates seen by X-ray spectroscopy was corroborated by molecular dynamics simulations and quantum mechanics/molecular mechanics calculations. The cysteine-zinc interaction that maintains enzyme latency is disrupted via active-site proton transfers that mediate transient metal-protein coordination events and eventual binding of water. Unexpectedly, these events ensue as a direct result of complexation of pro-MMP-9 and kallikrein and occur before proteolysis and eventual dissociation of the pro-peptide from the catalytic site. Here we demonstrate the synergism among long-range protein conformational transitions, local structural rearrangements, and fine atomic events in the process of zymogen activation.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
Sponsoring Organization:
Doe - Office Of Science
DOE Contract Number:
DE-AC02-98CH10886
OSTI ID:
959763
Report Number(s):
BNL-82749-2009-JA; JACSAT; TRN: US1005803
Journal Information:
Journal of the American Chemical Society, Vol. 129; ISSN 0002-7863
Country of Publication:
United States
Language:
English