Simplified method for determination of protocollagen proline hydroxylase

Preparation of (14C) Pro labeled protocollagen and requirements for its hydroxylation by PPH was investigated. Protocollagen can be prepared by centrifugation of the biological material at 15.000 X g. Substances in current use, viz catalase, bovine serum albumin and dithiothreitol were found unnecessary under the hydroxylation conditions used. A decrease in PPH in the testis and skin of rats with increasing age was demonstrated.