title: Human collagen digestion: I. Nature of the digestion kinetics as a function of age and structure.
abstract: The digestion of human collagen by bacterial collagenase was studied in order to relate collagen structure to the digestion kinetics. The digestion was shown to be first order in collagen and in collagenase on given material from run to run. There was no product inhibition and no enzyme deactivation. However, the rate changed with age, and also within a run as a function of conversion. It was shown that the normalized time (time X enzyme concentration), to reach a given amount of digestion can be plotted as a linear function of the sample age, from 20 to 70 years. The digestion broke down into two regions. The first was a rapid first order region which amounted to about 10% of the collagen. The second region could be graphed as a second order plot to obtain a straight line. This implied that the rate of digestion was functionally second order in collagen; first order in concentration and first order in conversion of collagen.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D002648:Child; D003094:Collagen / Q000378:metabolism*; D004063:Digestion; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D003012:Microbial Collagenase / Q000378:metabolism; D008875:Middle Aged; D011487:Protein Conformation; D012995:Solubility
chemical_list: D003094:Collagen; D003012:Microbial Collagenase