Activation and partial characterization of prolyl hydroxylase from regenerating limbs of the adult newt Notophthalmus viridescens.

Prolyl hydroxylase activity extracted from regenerating newt (Notophthalmus viridescens) limb tissues can be increased by brief preincubation with cofactors (ascorbate, alpha-ketoglutarate, Fe2+ and O2) prior to assay with [3H]proline-labeled collagen substrate. Newt prolyl hydroxylase is optimally active at 30 degrees C, but loses activity rapidly at 37 degrees C. The presence of cofactors or substrate decreases enzyme heat lability. Detergents (Triton X-100 and octyl glucoside) do not aid enzyme extraction and inhibit enzyme activity. Activity solubilized during homogenization without detergent remains soluble following high speed centrifugations. Comparative studies are reported for enzyme extracted from chick embryo tissues.