ASCORBIC-ACID UTILIZATION BY PROLYL HYDROXYLASE INVIVO

The treatment with 3,4-dehydro-D,L-proline, an analogous compound of proline which specifically inhibits prolyl hydroxylase, reduces the quantity of the hydroxyproline residues present in the polypeptide chains and at the same time leads to an increase in the ascorbic acid content in different plant tissues analysed (pea embryos, carrot and potato slices). The increase of ascorbic acid induced by dehydroproline treatment can be interpreted as a consequence of the reduced activity of the prolyl hydroxylase and suggests that in vivo the ascorbic acid acts as electron donor in the process of proline hydroxylation.