Evidence that chick tendon procollagen must be denatured to serve as substrate for proline hydroxylase (Short Communication)

The ability of chick-embryo proline hydroxylase to hydroxylate [¹⁴C]proline-labelled procollagen was investigated between 23° and 37°C. The amount of hydroxy[¹⁴C]proline that could be formed increased sharply between 26° and 30°C. This corresponded to the temperature interval in which the [¹⁴C]procollagen substrate was thermally denatured, and the results therefore indicate that only denatured molecules can be hydroxylated.