AN FPLC METHOD FOR DETERMINATION OF CALPAINS AND CALPASTATIN IN PORCINE M LONGISSIMUS-DORSI

Using a rapid FPLC procedure for the separation of calpain I, calpain II and the inhibitor calpastatin from pork meat, results of proteolytic and inhibitory activity were obtained. Duplicate measurements showed variation coefficients less than 0.13. Compared to others we found lower calpain I activity 1 h post-mortem. Three groups of pigs were randomly selected. One group was exposed to work immediately before slaughter, another group was exposed to work but allowed 30 min rest before slaughter, while the third group was a control group. Samples were taken from m longissimus dorsi 1 h and 6 h post-mortem. Work had no influence on the calpain/calpastatin activity, but a significant decrease in the calpain and calpastatin activity 6 h post-mortem was found. It should be noted that the results are preliminary and are part of an ongoing study. The method described allows separation of three extracts per instrument per day followed by activity determinations of calpains and calpastatin by the casein assay.