CHANGES IN QUALITATIVE COMPOSITION OF WHITE MUSCLE WITH NUTRITIONAL-STATUS OF ATLANTIC COD, GADUS-MORHUA

Proteins from white muscle are mobilized to cover energy requirements during long-term starvation in fish. Using SDS-polyacrylamide gel elec trophoresis, we compared the soluble and insoluble fractions of white muscle proteins from fed and starved Atlantic cod, Gadus morhua, to es tablish whether preferential preservation or degradation of specific p roteins occurred during starvation. While starvation induced no qualit ative changes in the electrophoretic pattern of the myofibrillar fract ion, our results document differential decreases in the levels of solu ble proteins during fasting. Moreover, immunoblot analysis using a mon oclonal antibody directed against actin, showed a marked accumulation of this protein in the sarcoplasmic fraction of starved individuals, m ost likely due to myofibrillar degradation. (C) 1998 Elsevier Science Inc. All rights reserved.