Fig. 3.

Enzyme-mediated mechanical integrity loss of individual collagen fibrils. Representative force versus strain data from mechanical probes performed each 300 s. a Control—no enzyme present. Note the relatively constant mechanical response at low strain values. b Low-load. Note the linearity of the force-strain response throughout enzymatic degradation. Fibril failed during the 3,300 s probe. c Zero-load data. Fibril failed during the 1,200 s probe. Note High-load data are not shown because no degradation was seen and the fibril was not mechanically probed, to avoid allowing degradation during the unloaded phase of mechanical probing