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 proteolyti c and inhibitory activity were obtained. Duplicate measurements showed variation coefficients less than 0.13. Compared to others we found lo wer calpain I activity 1 h post-mortem. Three groups of pigs were rand omly selected. One group was exposed to work immediately before slaugh ter, another group was exposed to work but allowed 30 min rest before slaughter, while the third group was a control group. Samples were tak en from m longissimus dorsi 1 h and 6 h post-mortem. Work had no influ ence on the calpain/calpastatin activity, but a significant decrease i n the calpain and calpastatin activity 6 h post-mortem was found. It s hould be noted that the results are preliminary and are part of an ong oing study. The method described allows separation of three extracts p er instrument per day followed by activity determinations of calpains and calpastatin by the casein assay.