Immunofluorescent localization of the Ca2+-dependent proteinase and its inhibitor in tissues of Crotalus atrox

The native 108,000 dalton Ca2+-dependent proteinase (CDP) and its 115,000 dalton protein inhibitor (CDPI) were purified from bovine skeletal muscle using native polyacrylamide gel electrophoresis and were used to elicit antibody production in rabbits and BALB/c mice. Polyclonal antibodies were purified as IgG fractions by column chromatography; monoclonal antibodyies were produced by the hybridoma technique. Indirect immunofluorescence localizations of CDP and CDPI in tissues of Crotalus atrox show both proteins to be ubiquitous. Both occur in the cytoplasm and are absent from the cell membrane and the nucleus; CDPI is also present in the I-band of skeletal muscle.