Degradation of neuropeptides by cytosolic and cytoskeleton-bound calcium-activated neutral proteases from bovine spinal cord

抄録

Cytosolic and cytoskeleton-bound calcium-activated neutral proteases (CANPs) requiring millimolar order Ca²⁺ were purified from bovine spinal cord, and their action on various neuropeptides and the B chain of oxidized insulin was examined. Both enzymes showed almost the same specificity toward the peptides used as substrates. They cleaved specifically the Arg-Arg bond in dynorphin and the ArgLys bonds in α- and β-neoendorphins, and fairly specifically the Tyr-X and/or PheX bond in neurotensin and angioterisin I. The enzymes also cleaved the Tyr-Leu bond in the B chain of oxidized insulin fairly selectively with additional cleavages occurring to a lesser extent on some other peptide bonds.