Insoluble collagen I. The effect of substrate weight on the rate of solubilisation of polymeric collagen fibrils by bacterial collagenase.

The enzymic solubilisation of insoluble collagen fibrils by bacterial collagenase has been examined employing unlabelled polymeric collagen fibrils (PC), rhodamine labelled fibrils (RB-PC), and fluorescein labelled fibrils (F-PC) as substrates. The presence of the label did not affect the kinetics of enzyme digestion but enabled the solubilized products to be rapidly estimated. The quantity of substrate used was found to play a major role in determining the quantity of peptides solubilised by a given enzyme concentration. It is suggested that in the PC fibrils only a limited number of TC molecules were suitably located to form an enzyme substrate complex with bacterial collagenase. Conditions were found in which the F-PC and RB-PC could be used as substrates in the assay of this enzyme.