The Effects of Catheptic Enzymes on Muscle Proteins

This work gives biochemical, ultrastructural and technological evidence for the use of spleen enzymes (cathepsins) as exogenous tenderizing agents. The extraction of the active enzyme fraction is shown. The release of the catheptic enzymes from the lysosomes occurs when the pH is lowered to 3.5. The subsequent lyophilate is rehydrated prior to its application. The catheptic enzymes found in the spleen extract are given. Attention has been focused on cathepsin D and B. As a model system of meat in order to examine the effect of these catheptic enzymes we chose bovine myofibrils. The effect of the action of the spleen enzymes was followed by electrophoretic analyses of the treated myofibrils. The most dramatic change is seen in the myosin which has decreased in molecular weight from 200,000 daltons to 145,000 daltons, other changes occurred in the regulatory proteins especially troponin I and troponin C. Changes in myosin might be expected to weaken the structure of the muscle fiber and lead to an alteration in tensile strength (a tenderization).