Assay and biochemical characterization of a dynorphin converting enzyme in human cerebrospinal fluid.

An endopeptidase hydrolyzing dynorphins A and B and alpha-neo-endorphin at the Arg6-Arg7 or Arg6-Lys7 bonds, was partially purified from human cerebrospinal fluid and further characterized by various biochemical techniques including HPLC gel permeation (UltroPac TSK G3000SW) and ion exchange (TSK DEAE-3SW) chromatography. A procedure for quantitative analysis of the enzyme in individual CSF samples is also described. The activity in lumbar CSF of women in late pregnancy was significantly lower than that in control samples.