Gel-sol transition can describe the proteolysis of extracellular matrix gels

We monitored the cell-free solubilization of extracellular matrix and fibronectin gels, catalyzed by exogenous proteinases. The corresponding measurements could not be interpreted according to usual proteinase kinetics. The observation that this experimental system did not consist in surface but in bulk degradation and appeared specific to gel substrates, incited us to use gelation-related approaches to describe these kinetics. We show that the gel-sol transition theory adequately describes the enzyme reactions. This allowed formulation and experimental confirmation of a power law relating macroscopic changes of the gel to enzyme kinetics. This approach could also be used for other power laws predicted by the gel-sol transition theory, allowing a better understanding of macroscopic modification of the extracellular matrix during proteolysis, which is implied in many biological situations, especially tumor dissemination. (C) 2000 Elsevier Science B.V. All rights reserved.