ABSTRACT
This chapter covers all aspects of experiments designed to measure the rate of collagen synthesis in whole animals, isolated tissues, or cell cultures. It describes methods to determine the relative and absolute rates of collagen synthesis and the rate of degradation. The disadvantage of biochemical method is that two reactions are measured: collagen synthesis and proline hydroxylation. Many commercial preparations of purified collagenase have been found to contain a substantial amount of noncollagen proteolytic enzyme activity. In many cell cultures, however, procollagen is processed quite slowly, so that various intermediates and very little mature a-chains are present, especially in short-term labeling experiments. In order to determine the absolute rate of synthesis of a protein in molar terms, the specific activity of the radioactive amino acid in the precursor amino acid pool of the cell or tissue must be measured.
