HPLC chromatogram for (a) <sup>D</sup>Ala substituted imino poor region of type I collagen at 37°C; (b) <sup>D</sup>Ala substituted imino poor region of type I collagen after 2 h incubation with bacterial collagenase at 37°C.

<p>HPLC chromatogram for (a) <sup>D</sup>Ala substituted imino poor region of type I collagen at 37°C; (b) <sup>D</sup>Ala substituted imino poor region of type I collagen after 2 h incubation with bacterial collagenase at 37°C.</p>